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2020-06-03fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()Alexander Potapenko
[ Upstream commit 1d605416fb7175e1adf094251466caa52093b413 ] KMSAN reported uninitialized data being written to disk when dumping core. As a result, several kilobytes of kmalloc memory may be written to the core file and then read by a non-privileged user. Reported-by: sam <sunhaoyl@outlook.com> Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200419100848.63472-1-glider@google.com Link: https://github.com/google/kmsan/issues/76 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-03cifs: Fix null pointer check in cifs_readSteve French
[ Upstream commit 9bd21d4b1a767c3abebec203342f3820dcb84662 ] Coverity scan noted a redundant null check Coverity-id: 728517 Reported-by: Coverity <scan-admin@coverity.com> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-03cachefiles: Fix race between read_waiter and read_copier involving op->to_doLei Xue
[ Upstream commit 7bb0c5338436dae953622470d52689265867f032 ] There is a potential race in fscache operation enqueuing for reading and copying multiple pages from cachefiles to netfs. The problem can be seen easily on a heavy loaded system (for example many processes reading files continually on an NFS share covered by fscache triggered this problem within a few minutes). The race is due to cachefiles_read_waiter() adding the op to the monitor to_do list and then then drop the object->work_lock spinlock before completing fscache_enqueue_operation(). Once the lock is dropped, cachefiles_read_copier() grabs the op, completes processing it, and makes it through fscache_retrieval_complete() which sets the op->state to the final state of FSCACHE_OP_ST_COMPLETE(4). When cachefiles_read_waiter() finally gets through the remainder of fscache_enqueue_operation() it sees the invalid state, and hits the ASSERTCMP and the following oops is seen: [ 2259.612361] FS-Cache: [ 2259.614785] FS-Cache: Assertion failed [ 2259.618639] FS-Cache: 4 == 5 is false [ 2259.622456] ------------[ cut here ]------------ [ 2259.627190] kernel BUG at fs/fscache/operation.c:70! ... [ 2259.791675] RIP: 0010:[<ffffffffc061b4cf>] [<ffffffffc061b4cf>] fscache_enqueue_operation+0xff/0x170 [fscache] [ 2259.802059] RSP: 0000:ffffa0263d543be0 EFLAGS: 00010046 [ 2259.807521] RAX: 0000000000000019 RBX: ffffa01a4d390480 RCX: 0000000000000006 [ 2259.814847] RDX: 0000000000000000 RSI: 0000000000000046 RDI: ffffa0263d553890 [ 2259.822176] RBP: ffffa0263d543be8 R08: 0000000000000000 R09: ffffa0263c2d8708 [ 2259.829502] R10: 0000000000001e7f R11: 0000000000000000 R12: ffffa01a4d390480 [ 2259.844483] R13: ffff9fa9546c5920 R14: ffffa0263d543c80 R15: ffffa0293ff9bf10 [ 2259.859554] FS: 00007f4b6efbd700(0000) GS:ffffa0263d540000(0000) knlGS:0000000000000000 [ 2259.875571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2259.889117] CR2: 00007f49e1624ff0 CR3: 0000012b38b38000 CR4: 00000000007607e0 [ 2259.904015] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 2259.918764] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 2259.933449] PKRU: 55555554 [ 2259.943654] Call Trace: [ 2259.953592] <IRQ> [ 2259.955577] [<ffffffffc03a7c12>] cachefiles_read_waiter+0x92/0xf0 [cachefiles] [ 2259.978039] [<ffffffffa34d3942>] __wake_up_common+0x82/0x120 [ 2259.991392] [<ffffffffa34d3a63>] __wake_up_common_lock+0x83/0xc0 [ 2260.004930] [<ffffffffa34d3510>] ? task_rq_unlock+0x20/0x20 [ 2260.017863] [<ffffffffa34d3ab3>] __wake_up+0x13/0x20 [ 2260.030230] [<ffffffffa34c72a0>] __wake_up_bit+0x50/0x70 [ 2260.042535] [<ffffffffa35bdcdb>] unlock_page+0x2b/0x30 [ 2260.054495] [<ffffffffa35bdd09>] page_endio+0x29/0x90 [ 2260.066184] [<ffffffffa368fc81>] mpage_end_io+0x51/0x80 CPU1 cachefiles_read_waiter() 20 static int cachefiles_read_waiter(wait_queue_entry_t *wait, unsigned mode, 21 int sync, void *_key) 22 { ... 61 spin_lock(&object->work_lock); 62 list_add_tail(&monitor->op_link, &op->to_do); 63 spin_unlock(&object->work_lock); <begin race window> 64 65 fscache_enqueue_retrieval(op); 182 static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op) 183 { 184 fscache_enqueue_operation(&op->op); 185 } 58 void fscache_enqueue_operation(struct fscache_operation *op) 59 { 60 struct fscache_cookie *cookie = op->object->cookie; 61 62 _enter("{OBJ%x OP%x,%u}", 63 op->object->debug_id, op->debug_id, atomic_read(&op->usage)); 64 65 ASSERT(list_empty(&op->pend_link)); 66 ASSERT(op->processor != NULL); 67 ASSERT(fscache_object_is_available(op->object)); 68 ASSERTCMP(atomic_read(&op->usage), >, 0); <end race window> CPU2 cachefiles_read_copier() 168 while (!list_empty(&op->to_do)) { ... 202 fscache_end_io(op, monitor->netfs_page, error); 203 put_page(monitor->netfs_page); 204 fscache_retrieval_complete(op, 1); CPU1 58 void fscache_enqueue_operation(struct fscache_operation *op) 59 { ... 69 ASSERTIFCMP(op->state != FSCACHE_OP_ST_IN_PROGRESS, 70 op->state, ==, FSCACHE_OP_ST_CANCELLED); Signed-off-by: Lei Xue <carmark.dlut@gmail.com> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-03gfs2: move privileged user check to gfs2_quota_lock_checkBob Peterson
[ Upstream commit 4ed0c30811cb4d30ef89850b787a53a84d5d2bcb ] Before this patch, function gfs2_quota_lock checked if it was called from a privileged user, and if so, it bypassed the quota check: superuser can operate outside the quotas. That's the wrong place for the check because the lock/unlock functions are separate from the lock_check function, and you can do lock and unlock without actually checking the quotas. This patch moves the check to gfs2_quota_lock_check. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27Revert "gfs2: Don't demote a glock until its revokes are written"Bob Peterson
[ Upstream commit b14c94908b1b884276a6608dea3d0b1b510338b7 ] This reverts commit df5db5f9ee112e76b5202fbc331f990a0fc316d6. This patch fixes a regression: patch df5db5f9ee112 allowed function run_queue() to bypass its call to do_xmote() if revokes were queued for the glock. That's wrong because its call to do_xmote() is what is responsible for calling the go_sync() glops functions to sync both the ail list and any revokes queued for it. By bypassing the call, gfs2 could get into a stand-off where the glock could not be demoted until its revokes are written back, but the revokes would not be written back because do_xmote() was never called. It "sort of" works, however, because there are other mechanisms like the log flush daemon (logd) that can sync the ail items and revokes, if it deems it necessary. The problem is: without file system pressure, it might never deem it necessary. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27ceph: fix double unlock in handle_cap_export()Wu Bo
[ Upstream commit 4d8e28ff3106b093d98bfd2eceb9b430c70a8758 ] If the ceph_mdsc_open_export_target_session() return fails, it will do a "goto retry", but the session mutex has already been unlocked. Re-lock the mutex in that case to ensure that we don't unlock it twice. Signed-off-by: Wu Bo <wubo40@huawei.com> Reviewed-by: "Yan, Zheng" <zyan@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27configfs: fix config_item refcnt leak in configfs_rmdir()Xiyu Yang
[ Upstream commit 8aebfffacfa379ba400da573a5bf9e49634e38cb ] configfs_rmdir() invokes configfs_get_config_item(), which returns a reference of the specified config_item object to "parent_item" with increased refcnt. When configfs_rmdir() returns, local variable "parent_item" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of configfs_rmdir(). When down_write_killable() fails, the function forgets to decrease the refcnt increased by configfs_get_config_item(), causing a refcnt leak. Fix this issue by calling config_item_put() when down_write_killable() fails. Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27fix multiplication overflow in copy_fdtable()Al Viro
[ Upstream commit 4e89b7210403fa4a8acafe7c602b6212b7af6c3b ] cpy and set really should be size_t; we won't get an overflow on that, since sysctl_nr_open can't be set above ~(size_t)0 / sizeof(void *), so nr that would've managed to overflow size_t on that multiplication won't get anywhere near copy_fdtable() - we'll fail with EMFILE before that. Cc: stable@kernel.org # v2.6.25+ Fixes: 9cfe015aa424 (get rid of NR_OPEN and introduce a sysctl_nr_open) Reported-by: Thiago Macieira <thiago.macieira@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20exec: Move would_dump into flush_old_execEric W. Biederman
commit f87d1c9559164294040e58f5e3b74a162bf7c6e8 upstream. I goofed when I added mm->user_ns support to would_dump. I missed the fact that in the case of binfmt_loader, binfmt_em86, binfmt_misc, and binfmt_script bprm->file is reassigned. Which made the move of would_dump from setup_new_exec to __do_execve_file before exec_binprm incorrect as it can result in would_dump running on the script instead of the interpreter of the script. The net result is that the code stopped making unreadable interpreters undumpable. Which allows them to be ptraced and written to disk without special permissions. Oops. The move was necessary because the call in set_new_exec was after bprm->mm was no longer valid. To correct this mistake move the misplaced would_dump from __do_execve_file into flos_old_exec, before exec_mmap is called. I tested and confirmed that without this fix I can attach with gdb to a script with an unreadable interpreter, and with this fix I can not. Cc: stable@vger.kernel.org Fixes: f84df2a6f268 ("exec: Ensure mm->user_ns contains the execed files") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20cifs: Fix a race condition with cifs_echo_requestRonnie Sahlberg
[ Upstream commit f2caf901c1b7ce65f9e6aef4217e3241039db768 ] There is a race condition with how we send (or supress and don't send) smb echos that will cause the client to incorrectly think the server is unresponsive and thus needs to be reconnected. Summary of the race condition: 1) Daisy chaining scheduling creates a gap. 2) If traffic comes unfortunate shortly after the last echo, the planned echo is suppressed. 3) Due to the gap, the next echo transmission is delayed until after the timeout, which is set hard to twice the echo interval. This is fixed by changing the timeouts from 2 to three times the echo interval. Detailed description of the bug: https://lutz.donnerhacke.de/eng/Blog/Groundhog-Day-with-SMB-remount Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20cifs: Check for timeout on Negotiate stageSamuel Cabrero
[ Upstream commit 76e752701a8af4404bbd9c45723f7cbd6e4a251e ] Some servers seem to accept connections while booting but never send the SMBNegotiate response neither close the connection, causing all processes accessing the share hang on uninterruptible sleep state. This happens when the cifs_demultiplex_thread detects the server is unresponsive so releases the socket and start trying to reconnect. At some point, the faulty server will accept the socket and the TCP status will be set to NeedNegotiate. The first issued command accessing the share will start the negotiation (pid 5828 below), but the response will never arrive so other commands will be blocked waiting on the mutex (pid 55352). This patch checks for unresponsive servers also on the negotiate stage releasing the socket and reconnecting if the response is not received and checking again the tcp state when the mutex is acquired. PID: 55352 TASK: ffff880fd6cc02c0 CPU: 0 COMMAND: "ls" #0 [ffff880fd9add9f0] schedule at ffffffff81467eb9 #1 [ffff880fd9addb38] __mutex_lock_slowpath at ffffffff81468fe0 #2 [ffff880fd9addba8] mutex_lock at ffffffff81468b1a #3 [ffff880fd9addbc0] cifs_reconnect_tcon at ffffffffa042f905 [cifs] #4 [ffff880fd9addc60] smb_init at ffffffffa042faeb [cifs] #5 [ffff880fd9addca0] CIFSSMBQPathInfo at ffffffffa04360b5 [cifs] .... Which is waiting a mutex owned by: PID: 5828 TASK: ffff880fcc55e400 CPU: 0 COMMAND: "xxxx" #0 [ffff880fbfdc19b8] schedule at ffffffff81467eb9 #1 [ffff880fbfdc1b00] wait_for_response at ffffffffa044f96d [cifs] #2 [ffff880fbfdc1b60] SendReceive at ffffffffa04505ce [cifs] #3 [ffff880fbfdc1bb0] CIFSSMBNegotiate at ffffffffa0438d79 [cifs] #4 [ffff880fbfdc1c50] cifs_negotiate_protocol at ffffffffa043b383 [cifs] #5 [ffff880fbfdc1c80] cifs_reconnect_tcon at ffffffffa042f911 [cifs] #6 [ffff880fbfdc1d20] smb_init at ffffffffa042faeb [cifs] #7 [ffff880fbfdc1d60] CIFSSMBQFSInfo at ffffffffa0434eb0 [cifs] .... Signed-off-by: Samuel Cabrero <scabrero@suse.de> Reviewed-by: Aurélien Aptel <aaptel@suse.de> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20chardev: add helper function to register char devs with a struct deviceLogan Gunthorpe
commit 233ed09d7fdacf592ee91e6c97ce5f4364fbe7c0 upstream. Credit for this patch goes is shared with Dan Williams [1]. I've taken things one step further to make the helper function more useful and clean up calling code. There's a common pattern in the kernel whereby a struct cdev is placed in a structure along side a struct device which manages the life-cycle of both. In the naive approach, the reference counting is broken and the struct device can free everything before the chardev code is entirely released. Many developers have solved this problem by linking the internal kobjs in this fashion: cdev.kobj.parent = &parent_dev.kobj; The cdev code explicitly gets and puts a reference to it's kobj parent. So this seems like it was intended to be used this way. Dmitrty Torokhov first put this in place in 2012 with this commit: 2f0157f char_dev: pin parent kobject and the first instance of the fix was then done in the input subsystem in the following commit: 4a215aa Input: fix use-after-free introduced with dynamic minor changes Subsequently over the years, however, this issue seems to have tripped up multiple developers independently. For example, see these commits: 0d5b7da iio: Prevent race between IIO chardev opening and IIO device (by Lars-Peter Clausen in 2013) ba0ef85 tpm: Fix initialization of the cdev (by Jason Gunthorpe in 2015) 5b28dde [media] media: fix use-after-free in cdev_put() when app exits after driver unbind (by Shauh Khan in 2016) This technique is similarly done in at least 15 places within the kernel and probably should have been done so in another, at least, 5 places. The kobj line also looks very suspect in that one would not expect drivers to have to mess with kobject internals in this way. Even highly experienced kernel developers can be surprised by this code, as seen in [2]. To help alleviate this situation, and hopefully prevent future wasted effort on this problem, this patch introduces a helper function to register a char device along with its parent struct device. This creates a more regular API for tying a char device to its parent without the developer having to set members in the underlying kobject. This patch introduce cdev_device_add and cdev_device_del which replaces a common pattern including setting the kobj parent, calling cdev_add and then calling device_add. It also introduces cdev_set_parent for the few cases that set the kobject parent without using device_add. [1] https://lkml.org/lkml/2017/2/13/700 [2] https://lkml.org/lkml/2017/2/10/370 Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20ext4: add cond_resched() to ext4_protect_reserved_inodeShijie Luo
commit af133ade9a40794a37104ecbcc2827c0ea373a3c upstream. When journal size is set too big by "mkfs.ext4 -J size=", or when we mount a crafted image to make journal inode->i_size too big, the loop, "while (i < num)", holds cpu too long. This could cause soft lockup. [ 529.357541] Call trace: [ 529.357551] dump_backtrace+0x0/0x198 [ 529.357555] show_stack+0x24/0x30 [ 529.357562] dump_stack+0xa4/0xcc [ 529.357568] watchdog_timer_fn+0x300/0x3e8 [ 529.357574] __hrtimer_run_queues+0x114/0x358 [ 529.357576] hrtimer_interrupt+0x104/0x2d8 [ 529.357580] arch_timer_handler_virt+0x38/0x58 [ 529.357584] handle_percpu_devid_irq+0x90/0x248 [ 529.357588] generic_handle_irq+0x34/0x50 [ 529.357590] __handle_domain_irq+0x68/0xc0 [ 529.357593] gic_handle_irq+0x6c/0x150 [ 529.357595] el1_irq+0xb8/0x140 [ 529.357599] __ll_sc_atomic_add_return_acquire+0x14/0x20 [ 529.357668] ext4_map_blocks+0x64/0x5c0 [ext4] [ 529.357693] ext4_setup_system_zone+0x330/0x458 [ext4] [ 529.357717] ext4_fill_super+0x2170/0x2ba8 [ext4] [ 529.357722] mount_bdev+0x1a8/0x1e8 [ 529.357746] ext4_mount+0x44/0x58 [ext4] [ 529.357748] mount_fs+0x50/0x170 [ 529.357752] vfs_kern_mount.part.9+0x54/0x188 [ 529.357755] do_mount+0x5ac/0xd78 [ 529.357758] ksys_mount+0x9c/0x118 [ 529.357760] __arm64_sys_mount+0x28/0x38 [ 529.357764] el0_svc_common+0x78/0x130 [ 529.357766] el0_svc_handler+0x38/0x78 [ 529.357769] el0_svc+0x8/0xc [ 541.356516] watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [mount:18674] Link: https://lore.kernel.org/r/20200211011752.29242-1-luoshijie1@huawei.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Shijie Luo <luoshijie1@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-20binfmt_elf: Do not move brk for INTERP-less ET_EXECKees Cook
commit 7be3cb019db1cbd5fd5ffe6d64a23fefa4b6f229 upstream. When brk was moved for binaries without an interpreter, it should have been limited to ET_DYN only. In other words, the special case was an ET_DYN that lacks an INTERP, not just an executable that lacks INTERP. The bug manifested for giant static executables, where the brk would end up in the middle of the text area on 32-bit architectures. Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in> Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20binfmt_elf: move brk out of mmap when doing direct loader execKees Cook
commit bbdc6076d2e5d07db44e74c11b01a3e27ab90b32 upstream. Commmit eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE"), made changes in the rare case when the ELF loader was directly invoked (e.g to set a non-inheritable LD_LIBRARY_PATH, testing new versions of the loader), by moving into the mmap region to avoid both ET_EXEC and PIE binaries. This had the effect of also moving the brk region into mmap, which could lead to the stack and brk being arbitrarily close to each other. An unlucky process wouldn't get its requested stack size and stack allocations could end up scribbling on the heap. This is illustrated here. In the case of using the loader directly, brk (so helpfully identified as "[heap]") is allocated with the _loader_ not the binary. For example, with ASLR entirely disabled, you can see this more clearly: $ /bin/cat /proc/self/maps 555555554000-55555555c000 r-xp 00000000 ... /bin/cat 55555575b000-55555575c000 r--p 00007000 ... /bin/cat 55555575c000-55555575d000 rw-p 00008000 ... /bin/cat 55555575d000-55555577e000 rw-p 00000000 ... [heap] ... 7ffff7ff7000-7ffff7ffa000 r--p 00000000 ... [vvar] 7ffff7ffa000-7ffff7ffc000 r-xp 00000000 ... [vdso] 7ffff7ffc000-7ffff7ffd000 r--p 00027000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffd000-7ffff7ffe000 rw-p 00028000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffe000-7ffff7fff000 rw-p 00000000 ... 7ffffffde000-7ffffffff000 rw-p 00000000 ... [stack] $ /lib/x86_64-linux-gnu/ld-2.27.so /bin/cat /proc/self/maps ... 7ffff7bcc000-7ffff7bd4000 r-xp 00000000 ... /bin/cat 7ffff7bd4000-7ffff7dd3000 ---p 00008000 ... /bin/cat 7ffff7dd3000-7ffff7dd4000 r--p 00007000 ... /bin/cat 7ffff7dd4000-7ffff7dd5000 rw-p 00008000 ... /bin/cat 7ffff7dd5000-7ffff7dfc000 r-xp 00000000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7fb2000-7ffff7fd6000 rw-p 00000000 ... 7ffff7ff7000-7ffff7ffa000 r--p 00000000 ... [vvar] 7ffff7ffa000-7ffff7ffc000 r-xp 00000000 ... [vdso] 7ffff7ffc000-7ffff7ffd000 r--p 00027000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffd000-7ffff7ffe000 rw-p 00028000 ... /lib/x86_64-linux-gnu/ld-2.27.so 7ffff7ffe000-7ffff8020000 rw-p 00000000 ... [heap] 7ffffffde000-7ffffffff000 rw-p 00000000 ... [stack] The solution is to move brk out of mmap and into ELF_ET_DYN_BASE since nothing is there in the direct loader case (and ET_EXEC is still far away at 0x400000). Anything that ran before should still work (i.e. the ultimately-launched binary already had the brk very far from its text, so this should be no different from a COMPAT_BRK standpoint). The only risk I see here is that if someone started to suddenly depend on the entire memory space lower than the mmap region being available when launching binaries via a direct loader execs which seems highly unlikely, I'd hope: this would mean a binary would _not_ work when exec()ed normally. (Note that this is only done under CONFIG_ARCH_HAS_ELF_RANDOMIZATION when randomization is turned on.) Link: http://lkml.kernel.org/r/20190422225727.GA21011@beast Link: https://lkml.kernel.org/r/CAGXu5jJ5sj3emOT2QPxQkNQk0qbU6zEfu9=Omfhx_p0nCKPSjA@mail.gmail.com Fixes: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Ali Saidi <alisaidi@amazon.com> Cc: Ali Saidi <alisaidi@amazon.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-10cifs: protect updating server->dstaddr with a spinlockRonnie Sahlberg
[ Upstream commit fada37f6f62995cc449b36ebba1220594bfe55fe ] We use a spinlock while we are reading and accessing the destination address for a server. We need to also use this spinlock to protect when we are modifying this address from reconn_set_ipaddr(). Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-05nfs: Fix potential posix_acl refcnt leak in nfs3_set_aclAndreas Gruenbacher
commit 7648f939cb919b9d15c21fff8cd9eba908d595dc upstream. nfs3_set_acl keeps track of the acl it allocated locally to determine if an acl needs to be released at the end. This results in a memory leak when the function allocates an acl as well as a default acl. Fix by releasing acls that differ from the acl originally passed into nfs3_set_acl. Fixes: b7fa0554cf1b ("[PATCH] NFS: Add support for NFSv3 ACLs") Reported-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-05btrfs: fix block group leak when removing failsXiyu Yang
commit f6033c5e333238f299c3ae03fac8cc1365b23b77 upstream. btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which returns a local reference of the block group that contains the given bytenr to "block_group" with increased refcount. When btrfs_remove_block_group() returns, "block_group" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in several exception handling paths of btrfs_remove_block_group(). When those error scenarios occur such as btrfs_alloc_path() returns NULL, the function forgets to decrease its refcnt increased by btrfs_lookup_block_group() and will cause a refcnt leak. Fix this issue by jumping to "out_put_group" label and calling btrfs_put_block_group() when those error scenarios occur. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-05ext4: fix special inode number checks in __ext4_iget()Theodore Ts'o
commit 191ce17876c9367819c4b0a25b503c0f6d9054d8 upstream. The check for special (reserved) inode number checks in __ext4_iget() was broken by commit 8a363970d1dc: ("ext4: avoid declaring fs inconsistent due to invalid file handles"). This was caused by a botched reversal of the sense of the flag now known as EXT4_IGET_SPECIAL (when it was previously named EXT4_IGET_NORMAL). Fix the logic appropriately. Fixes: 8a363970d1dc ("ext4: avoid declaring fs inconsistent...") Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@kernel.org Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02propagate_one(): mnt_set_mountpoint() needs mount_lockAl Viro
commit b0d3869ce9eeacbb1bbd541909beeef4126426d5 upstream. ... to protect the modification of mp->m_count done by it. Most of the places that modify that thing also have namespace_lock held, but not all of them can do so, so we really need mount_lock here. Kudos to Piotr Krysiuk <piotras@gmail.com>, who'd spotted a related bug in pivot_root(2) (fixed unnoticed in 5.3); search for other similar turds has caught out this one. Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: check for non-zero journal inum in ext4_calculate_overheadRitesh Harjani
commit f1eec3b0d0a849996ebee733b053efa71803dad5 upstream. While calculating overhead for internal journal, also check that j_inum shouldn't be 0. Otherwise we get below error with xfstests generic/050 with external journal (XXX_LOGDEV config) enabled. It could be simply reproduced with loop device with an external journal and marking blockdev as RO before mounting. [ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode # ------------[ cut here ]------------ generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2) WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0 CPU: 107 PID: 115347 Comm: mount Tainted: G L --------- -t - 4.18.0-167.el8.ppc64le #1 NIP: c0000000006f6d44 LR: c0000000006f6d40 CTR: 0000000030041dd4 <...> NIP [c0000000006f6d44] generic_make_request_checks+0x6b4/0x7d0 LR [c0000000006f6d40] generic_make_request_checks+0x6b0/0x7d0 <...> Call Trace: generic_make_request_checks+0x6b0/0x7d0 (unreliable) generic_make_request+0x3c/0x420 submit_bio+0xd8/0x200 submit_bh_wbc+0x1e8/0x250 __sync_dirty_buffer+0xd0/0x210 ext4_commit_super+0x310/0x420 [ext4] __ext4_error+0xa4/0x1e0 [ext4] __ext4_iget+0x388/0xe10 [ext4] ext4_get_journal_inode+0x40/0x150 [ext4] ext4_calculate_overhead+0x5a8/0x610 [ext4] ext4_fill_super+0x3188/0x3260 [ext4] mount_bdev+0x778/0x8f0 ext4_mount+0x28/0x50 [ext4] mount_fs+0x74/0x230 vfs_kern_mount.part.6+0x6c/0x250 do_mount+0x2fc/0x1280 sys_mount+0x158/0x180 system_call+0x5c/0x70 EXT4-fs (pmem1p2): no journal found EXT4-fs (pmem1p2): can't get journal size EXT4-fs (pmem1p2): mounted filesystem without journal. Opts: dax,norecovery Fixes: 3c816ded78bb ("ext4: use journal inode to determine journal overhead") Reported-by: Harish Sriram <harish@linux.ibm.com> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200316093038.25485-1-riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: unsigned int compared against zeroColin Ian King
commit fbbbbd2f28aec991f3fbc248df211550fbdfd58c upstream. There are two cases where u32 variables n and err are being checked for less than zero error values, the checks is always false because the variables are not signed. Fix this by making the variables ints. Addresses-Coverity: ("Unsigned compared against 0") Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Ashwin H <ashwinh@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: fix block validity checks for journal inodes using indirect blocksTheodore Ts'o
commit 170417c8c7bb2cbbdd949bf5c443c0c8f24a203b upstream. Commit 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity") failed to add an exception for the journal inode in ext4_check_blockref(), which is the function used by ext4_get_branch() for indirect blocks. This caused attempts to read from the ext3-style journals to fail with: [ 848.968550] EXT4-fs error (device sdb7): ext4_get_branch:171: inode #8: block 30343695: comm jbd2/sdb7-8: invalid block Fix this by adding the missing exception check. Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity") Reported-by: Arthur Marsh <arthur.marsh@internode.on.net> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Ashwin H <ashwinh@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: don't perform block validity checks on the journal inodeTheodore Ts'o
commit 0a944e8a6c66ca04c7afbaa17e22bf208a8b37f0 upstream. Since the journal inode is already checked when we added it to the block validity's system zone, if we check it again, we'll just trigger a failure. This was causing failures like this: [ 53.897001] EXT4-fs error (device sda): ext4_find_extent:909: inode #8: comm jbd2/sda-8: pblk 121667583 bad header/extent: invalid extent entries - magic f30a, entries 8, max 340(340), depth 0(0) [ 53.931430] jbd2_journal_bmap: journal block not found at offset 49 on sda-8 [ 53.938480] Aborting journal on device sda-8. ... but only if the system was under enough memory pressure that logical->physical mapping for the journal inode gets pushed out of the extent cache. (This is why it wasn't noticed earlier.) Fixes: 345c0dbf3a30 ("ext4: protect journal inode's blocks using block_validity") Reported-by: Dan Rue <dan.rue@linaro.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Ashwin H <ashwinh@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: protect journal inode's blocks using block_validityTheodore Ts'o
commit 345c0dbf3a30872d9b204db96b5857cd00808cae upstream. Add the blocks which belong to the journal inode to block_validity's system zone so attempts to deallocate or overwrite the journal due a corrupted file system where the journal blocks are also claimed by another inode. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202879 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Ashwin H <ashwinh@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: avoid declaring fs inconsistent due to invalid file handlesTheodore Ts'o
commit 8a363970d1dc38c4ec4ad575c862f776f468d057 upstream. If we receive a file handle, either from NFS or open_by_handle_at(2), and it points at an inode which has not been initialized, and the file system has metadata checksums enabled, we shouldn't try to get the inode, discover the checksum is invalid, and then declare the file system as being inconsistent. This can be reproduced by creating a test file system via "mke2fs -t ext4 -O metadata_csum /tmp/foo.img 8M", mounting it, cd'ing into that directory, and then running the following program. #define _GNU_SOURCE #include <fcntl.h> struct handle { struct file_handle fh; unsigned char fid[MAX_HANDLE_SZ]; }; int main(int argc, char **argv) { struct handle h = {{8, 1 }, { 12, }}; open_by_handle_at(AT_FDCWD, &h.fh, O_RDONLY); return 0; } Google-Bug-Id: 120690101 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Ashwin H <ashwinh@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ext4: convert BUG_ON's to WARN_ON's in mballoc.cTheodore Ts'o
[ Upstream commit 907ea529fc4c3296701d2bfc8b831dd2a8121a34 ] If the in-core buddy bitmap gets corrupted (or out of sync with the block bitmap), issue a WARN_ON and try to recover. In most cases this involves skipping trying to allocate out of a particular block group. We can end up declaring the file system corrupted, which is fair, since the file system probably should be checked before we proceed any further. Link: https://lore.kernel.org/r/20200414035649.293164-1-tytso@mit.edu Google-Bug-Id: 34811296 Google-Bug-Id: 34639169 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02xfs: fix partially uninitialized structure in xfs_reflink_remap_extentDarrick J. Wong
[ Upstream commit c142932c29e533ee892f87b44d8abc5719edceec ] In the reflink extent remap function, it turns out that uirec (the block mapping corresponding only to the part of the passed-in mapping that got unmapped) was not fully initialized. Specifically, br_state was not being copied from the passed-in struct to the uirec. This could lead to unpredictable results such as the reflinked mapping being marked unwritten in the destination file. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02nfsd: memory corruption in nfsd4_lock()Vasily Averin
commit e1e8399eee72e9d5246d4d1bcacd793debe34dd3 upstream. New struct nfsd4_blocked_lock allocated in find_or_allocate_block() does not initialized nbl_list and nbl_lru. If conflock allocation fails rollback can call list_del_init() access uninitialized fields and corrupt memory. v2: just initialize nbl_list and nbl_lru right after nbl allocation. Fixes: 76d348fadff5 ("nfsd: have nfsd4_lock use blocking locks for v4.1+ lock") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02fuse: fix possibly missed wake-up after abortMiklos Szeredi
commit 2d84a2d19b6150c6dbac1e6ebad9c82e4c123772 upstream. In current fuse_drop_waiting() implementation it's possible that fuse_wait_aborted() will not be woken up in the unlikely case that fuse_abort_conn() + fuse_wait_aborted() runs in between checking fc->connected and calling atomic_dec(&fc->num_waiting). Do the atomic_dec_and_test() unconditionally, which also provides the necessary barrier against reordering with the fc->connected check. The explicit smp_mb() in fuse_wait_aborted() is not actually needed, since the spin_unlock() in fuse_abort_conn() provides the necessary RELEASE barrier after resetting fc->connected. However, this is not a performance sensitive path, and adding the explicit barrier makes it easier to document. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: b8f95e5d13f5 ("fuse: umount should wait for all requests") Cc: <stable@vger.kernel.org> #v4.19 Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02vmalloc: fix remap_vmalloc_range() bounds checksJann Horn
commit bdebd6a2831b6fab69eb85cee74a8ba77f1a1cc2 upstream. remap_vmalloc_range() has had various issues with the bounds checks it promises to perform ("This function checks that addr is a valid vmalloc'ed area, and that it is big enough to cover the vma") over time, e.g.: - not detecting pgoff<<PAGE_SHIFT overflow - not detecting (pgoff<<PAGE_SHIFT)+usize overflow - not checking whether addr and addr+(pgoff<<PAGE_SHIFT) are the same vmalloc allocation - comparing a potentially wildly out-of-bounds pointer with the end of the vmalloc region In particular, since commit fc9702273e2e ("bpf: Add mmap() support for BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer dereferences by calling mmap() on a BPF map with a size that is bigger than the distance from the start of the BPF map to the end of the address space. This could theoretically be used as a kernel ASLR bypass, by using whether mmap() with a given offset oopses or returns an error code to perform a binary search over the possible address range. To allow remap_vmalloc_range_partial() to verify that addr and addr+(pgoff<<PAGE_SHIFT) are in the same vmalloc region, pass the offset to remap_vmalloc_range_partial() instead of adding it to the pointer in remap_vmalloc_range(). In remap_vmalloc_range_partial(), fix the check against get_vm_area_size() by using size comparisons instead of pointer comparisons, and add checks for pgoff. Fixes: 833423143c3a ("[PATCH] mm: introduce remap_vmalloc_range()") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Yonghong Song <yhs@fb.com> Cc: Andrii Nakryiko <andriin@fb.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@chromium.org> Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02fs/namespace.c: fix mountpoint reference counter racePiotr Krysiuk
A race condition between threads updating mountpoint reference counter affects longterm releases 4.4.220, 4.9.220, 4.14.177 and 4.19.118. The mountpoint reference counter corruption may occur when: * one thread increments m_count member of struct mountpoint [under namespace_sem, but not holding mount_lock] pivot_root() * another thread simultaneously decrements the same m_count [under mount_lock, but not holding namespace_sem] put_mountpoint() unhash_mnt() umount_mnt() mntput_no_expire() To fix this race condition, grab mount_lock before updating m_count in pivot_root(). Reference: CVE-2020-12114 Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-02ceph: don't skip updating wanted caps when cap is staleYan, Zheng
[ Upstream commit 0aa971b6fd3f92afef6afe24ef78d9bb14471519 ] 1. try_get_cap_refs() fails to get caps and finds that mds_wanted does not include what it wants. It returns -ESTALE. 2. ceph_get_caps() calls ceph_renew_caps(). ceph_renew_caps() finds that inode has cap, so it calls ceph_check_caps(). 3. ceph_check_caps() finds that issued caps (without checking if it's stale) already includes caps wanted by open file, so it skips updating wanted caps. Above events can cause an infinite loop inside ceph_get_caps(). Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02ceph: return ceph_mdsc_do_request() errors from __get_parent()Qiujun Huang
[ Upstream commit c6d50296032f0b97473eb2e274dc7cc5d0173847 ] Return the error returned by ceph_mdsc_do_request(). Otherwise, r_target_inode ends up being NULL this ends up returning ENOENT regardless of the error. Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02ext4: fix extent_status fragmentation for plain filesDmitry Monakhov
commit 4068664e3cd2312610ceac05b74c4cf1853b8325 upstream. Extents are cached in read_extent_tree_block(); as a result, extents are not cached for inodes with depth == 0 when we try to find the extent using ext4_find_extent(). The result of the lookup is cached in ext4_map_blocks() but is only a subset of the extent on disk. As a result, the contents of extents status cache can get very badly fragmented for certain workloads, such as a random 4k read workload. File size of /mnt/test is 33554432 (8192 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 8191: 40960.. 49151: 8192: last,eof $ perf record -e 'ext4:ext4_es_*' /root/bin/fio --name=t --direct=0 --rw=randread --bs=4k --filesize=32M --size=32M --filename=/mnt/test $ perf script | grep ext4_es_insert_extent | head -n 10 fio 131 [000] 13.975421: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [494/1) mapped 41454 status W fio 131 [000] 13.975939: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6064/1) mapped 47024 status W fio 131 [000] 13.976467: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6907/1) mapped 47867 status W fio 131 [000] 13.976937: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3850/1) mapped 44810 status W fio 131 [000] 13.977440: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3292/1) mapped 44252 status W fio 131 [000] 13.977931: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6882/1) mapped 47842 status W fio 131 [000] 13.978376: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3117/1) mapped 44077 status W fio 131 [000] 13.978957: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [2896/1) mapped 43856 status W fio 131 [000] 13.979474: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [7479/1) mapped 48439 status W Fix this by caching the extents for inodes with depth == 0 in ext4_find_extent(). [ Renamed ext4_es_cache_extents() to ext4_cache_extents() since this newly added function is not in extents_cache.c, and to avoid potential visual confusion with ext4_es_cache_extent(). -TYT ] Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com> Link: https://lore.kernel.org/r/20191106122502.19986-1-dmonakhov@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24ext2: fix debug reference to ext2_xattr_cacheJan Kara
[ Upstream commit 32302085a8d90859c40cf1a5e8313f575d06ec75 ] Fix a debug-only build error in ext2/xattr.c: When building without extra debugging, (and with another patch that uses no_printk() instead of <empty> for the ext2-xattr debug-print macros, this build error happens: ../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’: ../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in this function); did you mean ‘ext2_xattr_list’? atomic_read(&ext2_xattr_cache->c_entry_count)); Fix the problem by removing cached entry count from the debug message since otherwise we'd have to export the mbcache structure just for that. Fixes: be0726d33cb8 ("ext2: convert to mbcache2") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24ext2: fix empty body warnings when -Wextra is usedRandy Dunlap
[ Upstream commit 44a52022e7f15cbaab957df1c14f7a4f527ef7cf ] When EXT2_ATTR_DEBUG is not defined, modify the 2 debug macros to use the no_printk() macro instead of <nothing>. This fixes gcc warnings when -Wextra is used: ../fs/ext2/xattr.c:252:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../fs/ext2/xattr.c:258:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../fs/ext2/xattr.c:330:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../fs/ext2/xattr.c:872:45: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body] I have verified that the only object code change (with gcc 7.5.0) is the reversal of some instructions from 'cmp a,b' to 'cmp b,a'. Link: https://lore.kernel.org/r/e18a7395-61fb-2093-18e8-ed4f8cf56248@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jan Kara <jack@suse.com> Cc: linux-ext4@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24NFS: Fix memory leaks in nfs_pageio_stop_mirroring()Trond Myklebust
[ Upstream commit 862f35c94730c9270833f3ad05bd758a29f204ed ] If we just set the mirror count to 1 without first clearing out the mirrors, we can leak queued up requests. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24ext4: do not commit super on read-only bdevEric Sandeen
[ Upstream commit c96e2b8564adfb8ac14469ebc51ddc1bfecb3ae2 ] Under some circumstances we may encounter a filesystem error on a read-only block device, and if we try to save the error info to the superblock and commit it, we'll wind up with a noisy error and backtrace, i.e.: [ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode # ------------[ cut here ]------------ generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2) WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0 ... To avoid this, commit the error info in the superblock only if the block device is writable. Reported-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/4b6e774d-cc00-3469-7abb-108eb151071a@sandeen.net Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24NFS: direct.c: Fix memory leak of dreq when nfs_get_lock_context failsMisono Tomohiro
[ Upstream commit 8605cf0e852af3b2c771c18417499dc4ceed03d5 ] When dreq is allocated by nfs_direct_req_alloc(), dreq->kref is initialized to 2. Therefore we need to call nfs_direct_req_release() twice to release the allocated dreq. Usually it is called in nfs_file_direct_{read, write}() and nfs_direct_complete(). However, current code only calls nfs_direct_req_relese() once if nfs_get_lock_context() fails in nfs_file_direct_{read, write}(). So, that case would result in memory leak. Fix this by adding the missing call. Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24ext4: do not zeroout extents beyond i_disksizeJan Kara
commit 801674f34ecfed033b062a0f217506b93c8d5e8a upstream. We do not want to create initialized extents beyond end of file because for e2fsck it is impossible to distinguish them from a case of corrupted file size / extent tree and so it complains like: Inode 12, i_size is 147456, should be 163840. Fix? no Code in ext4_ext_convert_to_initialized() and ext4_split_convert_extents() try to make sure it does not create initialized extents beyond inode size however they check against inode->i_size which is wrong. They should instead check against EXT4_I(inode)->i_disksize which is the current inode size on disk. That's what e2fsck is going to see in case of crash before all dirty data is written. This bug manifests as generic/456 test failure (with recent enough fstests where fsx got fixed to properly pass FALLOC_KEEP_SIZE_FL flags to the kernel) when run with dioread_lock mount option. CC: stable@vger.kernel.org Fixes: 21ca087a3891 ("ext4: Do not zero out uninitialized extents beyond i_size") Reviewed-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Link: https://lore.kernel.org/r/20200331105016.8674-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24btrfs: check commit root generation in should_ignore_rootJosef Bacik
commit 4d4225fc228e46948486d8b8207955f0c031b92e upstream. Previously we would set the reloc root's last snapshot to transid - 1. However there was a problem with doing this, and we changed it to setting the last snapshot to the generation of the commit node of the fs root. This however broke should_ignore_root(). The assumption is that if we are in a generation newer than when the reloc root was created, then we would find the reloc root through normal backref lookups, and thus can ignore any fs roots we find with an old enough reloc root. Now that the last snapshot could be considerably further in the past than before, we'd end up incorrectly ignoring an fs root. Thus we'd find no nodes for the bytenr we were searching for, and we'd fail to relocate anything. We'd loop through the relocate code again and see that there were still used space in that block group, attempt to relocate those bytenr's again, fail in the same way, and just loop like this forever. This is tricky in that we have to not modify the fs root at all during this time, so we need to have a block group that has data in this fs root that is not shared by any other root, which is why this has been difficult to reproduce. Fixes: 054570a1dc94 ("Btrfs: fix relocation incorrectly dropping data references") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24ext4: fix incorrect inodes per group in error messageJosh Triplett
commit b9c538da4e52a7b79dfcf4cfa487c46125066dfb upstream. If ext4_fill_super detects an invalid number of inodes per group, the resulting error message printed the number of blocks per group, rather than the number of inodes per group. Fix it to print the correct value. Fixes: cd6bb35bf7f6d ("ext4: use more strict checks for inodes_per_block on mount") Link: https://lore.kernel.org/r/8be03355983a08e5d4eed480944613454d7e2550.1585434649.git.josh@joshtriplett.org Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24ext4: fix incorrect group count in ext4_fill_super error messageJosh Triplett
commit df41460a21b06a76437af040d90ccee03888e8e5 upstream. ext4_fill_super doublechecks the number of groups before mounting; if that check fails, the resulting error message prints the group count from the ext4_sb_info sbi, which hasn't been set yet. Print the freshly computed group count instead (which at that point has just been computed in "blocks_count"). Signed-off-by: Josh Triplett <josh@joshtriplett.org> Fixes: 4ec1102813798 ("ext4: Add sanity checks for the superblock before mounting the filesystem") Link: https://lore.kernel.org/r/8b957cd1513fcc4550fe675c10bcce2175c33a49.1585431964.git.josh@joshtriplett.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24jbd2: improve comments about freeing data buffers whose page mapping is NULLzhangyi (F)
commit 780f66e59231fcf882f36c63f287252ee47cc75a upstream. Improve comments in jbd2_journal_commit_transaction() to describe why we don't need to clear the buffer_mapped bit for freeing file mapping buffers whose page mapping is NULL. Link: https://lore.kernel.org/r/20200217112706.20085-1-yi.zhang@huawei.com Fixes: c96dceeabf76 ("jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer") Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24Btrfs: fix crash during unmount due to race with delayed inode workersFilipe Manana
[ Upstream commit f0cc2cd70164efe8f75c5d99560f0f69969c72e4 ] During unmount we can have a job from the delayed inode items work queue still running, that can lead to at least two bad things: 1) A crash, because the worker can try to create a transaction just after the fs roots were freed; 2) A transaction leak, because the worker can create a transaction before the fs roots are freed and just after we committed the last transaction and after we stopped the transaction kthread. A stack trace example of the crash: [79011.691214] kernel BUG at lib/radix-tree.c:982! [79011.692056] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI [79011.693180] CPU: 3 PID: 1394 Comm: kworker/u8:2 Tainted: G W 5.6.0-rc2-btrfs-next-54 #2 (...) [79011.696789] Workqueue: btrfs-delayed-meta btrfs_work_helper [btrfs] [79011.697904] RIP: 0010:radix_tree_tag_set+0xe7/0x170 (...) [79011.702014] RSP: 0018:ffffb3c84a317ca0 EFLAGS: 00010293 [79011.702949] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [79011.704202] RDX: ffffb3c84a317cb0 RSI: ffffb3c84a317ca8 RDI: ffff8db3931340a0 [79011.705463] RBP: 0000000000000005 R08: 0000000000000005 R09: ffffffff974629d0 [79011.706756] R10: ffffb3c84a317bc0 R11: 0000000000000001 R12: ffff8db393134000 [79011.708010] R13: ffff8db3931340a0 R14: ffff8db393134068 R15: 0000000000000001 [79011.709270] FS: 0000000000000000(0000) GS:ffff8db3b6a00000(0000) knlGS:0000000000000000 [79011.710699] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [79011.711710] CR2: 00007f22c2a0a000 CR3: 0000000232ad4005 CR4: 00000000003606e0 [79011.712958] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [79011.714205] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [79011.715448] Call Trace: [79011.715925] record_root_in_trans+0x72/0xf0 [btrfs] [79011.716819] btrfs_record_root_in_trans+0x4b/0x70 [btrfs] [79011.717925] start_transaction+0xdd/0x5c0 [btrfs] [79011.718829] btrfs_async_run_delayed_root+0x17e/0x2b0 [btrfs] [79011.719915] btrfs_work_helper+0xaa/0x720 [btrfs] [79011.720773] process_one_work+0x26d/0x6a0 [79011.721497] worker_thread+0x4f/0x3e0 [79011.722153] ? process_one_work+0x6a0/0x6a0 [79011.722901] kthread+0x103/0x140 [79011.723481] ? kthread_create_worker_on_cpu+0x70/0x70 [79011.724379] ret_from_fork+0x3a/0x50 (...) The following diagram shows a sequence of steps that lead to the crash during ummount of the filesystem: CPU 1 CPU 2 CPU 3 btrfs_punch_hole() btrfs_btree_balance_dirty() btrfs_balance_delayed_items() --> sees fs_info->delayed_root->items with value 200, which is greater than BTRFS_DELAYED_BACKGROUND (128) and smaller than BTRFS_DELAYED_WRITEBACK (512) btrfs_wq_run_delayed_node() --> queues a job for fs_info->delayed_workers to run btrfs_async_run_delayed_root() btrfs_async_run_delayed_root() --> job queued by CPU 1 --> starts picking and running delayed nodes from the prepare_list list close_ctree() btrfs_delete_unused_bgs() btrfs_commit_super() btrfs_join_transaction() --> gets transaction N btrfs_commit_transaction(N) --> set transaction state to TRANTS_STATE_COMMIT_START btrfs_first_prepared_delayed_node() --> picks delayed node X through the prepared_list list btrfs_run_delayed_items() btrfs_first_delayed_node() --> also picks delayed node X but through the node_list list __btrfs_commit_inode_delayed_items() --> runs all delayed items from this node and drops the node's item count to 0 through call to btrfs_release_delayed_inode() --> finishes running any remaining delayed nodes --> finishes transaction commit --> stops cleaner and transaction threads btrfs_free_fs_roots() --> frees all roots and removes them from the radix tree fs_info->fs_roots_radix btrfs_join_transaction() start_transaction() btrfs_record_root_in_trans() record_root_in_trans() radix_tree_tag_set() --> crashes because the root is not in the radix tree anymore If the worker is able to call btrfs_join_transaction() before the unmount task frees the fs roots, we end up leaking a transaction and all its resources, since after the call to btrfs_commit_super() and stopping the transaction kthread, we don't expect to have any transaction open anymore. When this situation happens the worker has a delayed node that has no more items to run, since the task calling btrfs_run_delayed_items(), which is doing a transaction commit, picks the same node and runs all its items first. We can not wait for the worker to complete when running delayed items through btrfs_run_delayed_items(), because we call that function in several phases of a transaction commit, and that could cause a deadlock because the worker calls btrfs_join_transaction() and the task doing the transaction commit may have already set the transaction state to TRANS_STATE_COMMIT_DOING. Also it's not possible to get into a situation where only some of the items of a delayed node are added to the fs/subvolume tree in the current transaction and the remaining ones in the next transaction, because when running the items of a delayed inode we lock its mutex, effectively waiting for the worker if the worker is running the items of the delayed node already. Since this can only cause issues when unmounting a filesystem, fix it in a simple way by waiting for any jobs on the delayed workers queue before calling btrfs_commit_supper() at close_ctree(). This works because at this point no one can call btrfs_btree_balance_dirty() or btrfs_balance_delayed_items(), and if we end up waiting for any worker to complete, btrfs_commit_super() will commit the transaction created by the worker. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24hfsplus: fix crash and filesystem corruption when deleting filesSimon Gander
commit 25efb2ffdf991177e740b2f63e92b4ec7d310a92 upstream. When removing files containing extended attributes, the hfsplus driver may remove the wrong entries from the attributes b-tree, causing major filesystem damage and in some cases even kernel crashes. To remove a file, all its extended attributes have to be removed as well. The driver does this by looking up all keys in the attributes b-tree with the cnid of the file. Each of these entries then gets deleted using the key used for searching, which doesn't contain the attribute's name when it should. Since the key doesn't contain the name, the deletion routine will not find the correct entry and instead remove the one in front of it. If parent nodes have to be modified, these become corrupt as well. This causes invalid links and unsorted entries that not even macOS's fsck_hfs is able to fix. To fix this, modify the search key before an entry is deleted from the attributes b-tree by copying the found entry's key into the search key, therefore ensuring that the correct entry gets removed from the tree. Signed-off-by: Simon Gander <simon@tuxera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Anton Altaparmakov <anton@tuxera.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200327155541.1521-1-simon@tuxera.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24ocfs2: no need try to truncate file beyond i_sizeChangwei Ge
commit 783fda856e1034dee90a873f7654c418212d12d7 upstream. Linux fallocate(2) with FALLOC_FL_PUNCH_HOLE mode set, its offset can exceed the inode size. Ocfs2 now doesn't allow that offset beyond inode size. This restriction is not necessary and violates fallocate(2) semantics. If fallocate(2) offset is beyond inode size, just return success and do nothing further. Otherwise, ocfs2 will crash the kernel. kernel BUG at fs/ocfs2//alloc.c:7264! ocfs2_truncate_inline+0x20f/0x360 [ocfs2] ocfs2_remove_inode_range+0x23c/0xcb0 [ocfs2] __ocfs2_change_file_space+0x4a5/0x650 [ocfs2] ocfs2_fallocate+0x83/0xa0 [ocfs2] vfs_fallocate+0x148/0x230 SyS_fallocate+0x48/0x80 do_syscall_64+0x79/0x170 Signed-off-by: Changwei Ge <chge@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200407082754.17565-1-chge@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24ext4: fix a data race at inode->i_blocksQian Cai
commit 28936b62e71e41600bab319f262ea9f9b1027629 upstream. inode->i_blocks could be accessed concurrently as noticed by KCSAN, BUG: KCSAN: data-race in ext4_do_update_inode [ext4] / inode_add_bytes write to 0xffff9a00d4b982d0 of 8 bytes by task 22100 on cpu 118: inode_add_bytes+0x65/0xf0 __inode_add_bytes at fs/stat.c:689 (inlined by) inode_add_bytes at fs/stat.c:702 ext4_mb_new_blocks+0x418/0xca0 [ext4] ext4_ext_map_blocks+0x1a6b/0x27b0 [ext4] ext4_map_blocks+0x1a9/0x950 [ext4] _ext4_get_block+0xfc/0x270 [ext4] ext4_get_block_unwritten+0x33/0x50 [ext4] __block_write_begin_int+0x22e/0xae0 __block_write_begin+0x39/0x50 ext4_write_begin+0x388/0xb50 [ext4] ext4_da_write_begin+0x35f/0x8f0 [ext4] generic_perform_write+0x15d/0x290 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe read to 0xffff9a00d4b982d0 of 8 bytes by task 8 on cpu 65: ext4_do_update_inode+0x4a0/0xf60 [ext4] ext4_inode_blocks_set at fs/ext4/inode.c:4815 ext4_mark_iloc_dirty+0xaf/0x160 [ext4] ext4_mark_inode_dirty+0x129/0x3e0 [ext4] ext4_convert_unwritten_extents+0x253/0x2d0 [ext4] ext4_convert_unwritten_io_end_vec+0xc5/0x150 [ext4] ext4_end_io_rsv_work+0x22c/0x350 [ext4] process_one_work+0x54f/0xb90 worker_thread+0x80/0x5f0 kthread+0x1cd/0x1f0 ret_from_fork+0x27/0x50 4 locks held by kworker/u256:0/8: #0: ffff9a025abc4328 ((wq_completion)ext4-rsv-conversion){+.+.}, at: process_one_work+0x443/0xb90 #1: ffffab5a862dbe20 ((work_completion)(&ei->i_rsv_conversion_work)){+.+.}, at: process_one_work+0x443/0xb90 #2: ffff9a025a9d0f58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2] #3: ffff9a00d4b985d8 (&(&ei->i_raw_lock)->rlock){+.+.}, at: ext4_do_update_inode+0xaa/0xf60 [ext4] irq event stamp: 3009267 hardirqs last enabled at (3009267): [<ffffffff980da9b7>] __find_get_block+0x107/0x790 hardirqs last disabled at (3009266): [<ffffffff980da8f9>] __find_get_block+0x49/0x790 softirqs last enabled at (3009230): [<ffffffff98a0034c>] __do_softirq+0x34c/0x57c softirqs last disabled at (3009223): [<ffffffff97cc67a2>] irq_exit+0xa2/0xc0 Reported by Kernel Concurrency Sanitizer on: CPU: 65 PID: 8 Comm: kworker/u256:0 Tainted: G L 5.6.0-rc2-next-20200221+ #7 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work [ext4] The plain read is outside of inode->i_lock critical section which results in a data race. Fix it by adding READ_ONCE() there. Link: https://lore.kernel.org/r/20200222043258.2279-1-cai@lca.pw Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-24btrfs: drop block from cache on error in relocationJosef Bacik
commit 8e19c9732ad1d127b5575a10f4fbcacf740500ff upstream. If we have an error while building the backref tree in relocation we'll process all the pending edges and then free the node. However if we integrated some edges into the cache we'll lose our link to those edges by simply freeing this node, which means we'll leak memory and references to any roots that we've found. Instead we need to use remove_backref_node(), which walks through all of the edges that are still linked to this node and free's them up and drops any root references we may be holding. CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>