summaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2024-03-04x86/boot: Move mem_encrypt= parsing to the decompressorArd Biesheuvel
The early SME/SEV code parses the command line very early, in order to decide whether or not memory encryption should be enabled, which needs to occur even before the initial page tables are created. This is problematic for a number of reasons: - this early code runs from the 1:1 mapping provided by the decompressor or firmware, which uses a different translation than the one assumed by the linker, and so the code needs to be built in a special way; - parsing external input while the entire kernel image is still mapped writable is a bad idea in general, and really does not belong in security minded code; - the current code ignores the built-in command line entirely (although this appears to be the case for the entire decompressor) Given that the decompressor/EFI stub is an intrinsic part of the x86 bootable kernel image, move the command line parsing there and out of the core kernel. This removes the need to build lib/cmdline.o in a special way, or to use RIP-relative LEA instructions in inline asm blocks. This involves a new xloadflag in the setup header to indicate that mem_encrypt=on appeared on the kernel command line. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-17-ardb+git@google.com
2024-03-04efi/libstub: Add generic support for parsing mem_encrypt=Ard Biesheuvel
Parse the mem_encrypt= command line parameter from the EFI stub if CONFIG_ARCH_HAS_MEM_ENCRYPT=y, so that it can be passed to the early boot code by the arch code in the stub. This avoids the need for the core kernel to do any string parsing very early in the boot. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-16-ardb+git@google.com
2024-03-04x86/startup_64: Simplify virtual switch on primary bootArd Biesheuvel
The secondary startup code is used on the primary boot path as well, but in this case, the initial part runs from a 1:1 mapping, until an explicit cross-jump is made to the kernel virtual mapping of the same code. On the secondary boot path, this jump is pointless as the code already executes from the mapping targeted by the jump. So combine this cross-jump with the jump from startup_64() into the common boot path. This simplifies the execution flow, and clearly separates code that runs from a 1:1 mapping from code that runs from the kernel virtual mapping. Note that this requires a page table switch, so hoist the CR3 assignment into startup_64() as well. And since absolute symbol references will no longer be permitted in .head.text once we enable the associated build time checks, a RIP-relative memory operand is used in the JMP instruction, referring to an absolute constant in the .init.rodata section. Given that the secondary startup code does not require a special placement inside the executable, move it to the .text section. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-15-ardb+git@google.com
2024-03-04x86/startup_64: Simplify calculation of initial page table addressArd Biesheuvel
Determining the address of the initial page table to program into CR3 involves: - taking the physical address - adding the SME encryption mask On the primary entry path, the code is mapped using a 1:1 virtual to physical translation, so the physical address can be taken directly using a RIP-relative LEA instruction. On the secondary entry path, the address can be obtained by taking the offset from the virtual kernel base (__START_kernel_map) and adding the physical kernel base. This is implemented in a slightly confusing way, so clean this up. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-14-ardb+git@google.com
2024-03-04x86/startup_64: Defer assignment of 5-level paging global variablesArd Biesheuvel
Assigning the 5-level paging related global variables from the earliest C code using explicit references that use the 1:1 translation of memory is unnecessary, as the startup code itself does not rely on them to create the initial page tables, and this is all it should be doing. So defer these assignments to the primary C entry code that executes via the ordinary kernel virtual mapping. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-13-ardb+git@google.com
2024-03-04x86/startup_64: Simplify CR4 handling in startup codeArd Biesheuvel
When paging is enabled, the CR4.PAE and CR4.LA57 control bits cannot be changed, and so they can simply be preserved rather than reason about whether or not they need to be set. CR4.MCE should be preserved unless the kernel was built without CONFIG_X86_MCE, in which case it must be cleared. CR4.PSE should be set explicitly, regardless of whether or not it was set before. CR4.PGE is set explicitly, and then cleared and set again after programming CR3 in order to flush TLB entries based on global translations. This makes the first assignment redundant, and can therefore be omitted. So clear PGE by omitting it from the preserve mask, and set it again explicitly after switching to the new page tables. [ bp: Document the exact operation of CR4.PGE ] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20240227151907.387873-12-ardb+git@google.com
2024-03-01x86/boot: Use 32-bit XOR to clear registersUros Bizjak
x86_64 zero extends 32-bit operations, so for 64-bit operands, XORL r32,r32 is functionally equal to XORQ r64,r64, but avoids a REX prefix byte when legacy registers are used. Slightly smaller code generated, no change in functionality. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240124103859.611372-1-ubizjak@gmail.com
2024-02-28efi/x86: Set the PE/COFF header's NX compat flag unconditionallyArd Biesheuvel
Now that the proper section and file alignment is used, and the EFI memory attributes protocol to manage executable permissions where needed is invoked, set the NX compat flag unconditionally. [ bp: Remove the "we"s. ] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20240116085347.2193966-2-ardb+git@google.com
2024-02-28x86/boot/64: Load the final kernel GDT during early boot directly, remove ↵Brian Gerst
startup_gdt[] Instead of loading a duplicate GDT just for early boot, load the kernel GDT from its physical address. Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20240226220544.70769-1-brgerst@gmail.com
2024-02-26x86/boot/64: Use RIP_REL_REF() to access early_top_pgt[]Ard Biesheuvel
early_top_pgt[] is assigned from code that executes from a 1:1 mapping so it cannot use a plain access from C. Replace the use of fixup_pointer() with RIP_REL_REF(), which is better and simpler. For legibility and to align with the code that populates the lower page table levels, statically initialize the root level page table with an entry pointing to level3_kernel_pgt[], and overwrite it when needed to enable 5-level paging. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240221113506.2565718-24-ardb+git@google.com
2024-02-26x86/boot/64: Use RIP_REL_REF() to access early page tablesArd Biesheuvel
The early statically allocated page tables are populated from code that executes from a 1:1 mapping so it cannot use plain accesses from C. Replace the use of fixup_pointer() with RIP_REL_REF(), which is better and simpler. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240221113506.2565718-23-ardb+git@google.com
2024-02-26x86/boot/64: Use RIP_REL_REF() to access '__supported_pte_mask'Ard Biesheuvel
'__supported_pte_mask' is accessed from code that executes from a 1:1 mapping so it cannot use a plain access from C. Replace the use of fixup_pointer() with RIP_REL_REF(), which is better and simpler. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240221113506.2565718-22-ardb+git@google.com
2024-02-26x86/boot/64: Use RIP_REL_REF() to access early_dynamic_pgts[]Ard Biesheuvel
early_dynamic_pgts[] and next_early_pgt are accessed from code that executes from a 1:1 mapping so it cannot use a plain access from C. Replace the use of fixup_pointer() with RIP_REL_REF(), which is better and simpler. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240221113506.2565718-21-ardb+git@google.com
2024-02-26x86/boot/64: Use RIP_REL_REF() to assign 'phys_base'Ard Biesheuvel
'phys_base' is assigned from code that executes from a 1:1 mapping so it cannot use a plain access from C. Replace the use of fixup_pointer() with RIP_REL_REF(), which is better and simpler. While at it, move the assignment to before the addition of the SME mask so there is no need to subtract it again, and drop the unnecessary addition ('phys_base' is statically initialized to 0x0) Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240221113506.2565718-20-ardb+git@google.com
2024-02-26x86/boot/64: Simplify global variable accesses in GDT/IDT programmingArd Biesheuvel
There are two code paths in the startup code to program an IDT: one that runs from the 1:1 mapping and one that runs from the virtual kernel mapping. Currently, these are strictly separate because fixup_pointer() is used on the 1:1 path, which will produce the wrong value when used while executing from the virtual kernel mapping. Switch to RIP_REL_REF() so that the two code paths can be merged. Also, move the GDT and IDT descriptors to the stack so that they can be referenced directly, rather than via RIP_REL_REF(). Rename startup_64_setup_env() to startup_64_setup_gdt_idt() while at it, to make the call from assembler self-documenting. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240221113506.2565718-19-ardb+git@google.com
2024-02-26Merge branch 'x86/sev' into x86/boot, to resolve conflicts and to pick up ↵Ingo Molnar
dependent tree We are going to queue up a number of patches that depend on fresh changes in x86/sev - merge in that branch to reduce the number of conflicts going forward. Also resolve a current conflict with x86/sev. Conflicts: arch/x86/include/asm/coco.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-02-26Merge tag 'v6.8-rc6' into x86/boot, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-02-25Linux 6.8-rc6v6.8-rc6Linus Torvalds
2024-02-25Merge tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefsLinus Torvalds
Pull bcachefs fixes from Kent Overstreet: "Some more mostly boring fixes, but some not User reported ones: - the BTREE_ITER_FILTER_SNAPSHOTS one fixes a really nasty performance bug; user reported an untar initially taking two seconds and then ~2 minutes - kill a __GFP_NOFAIL in the buffered read path; this was a leftover from the trickier fix to kill __GFP_NOFAIL in readahead, where we can't return errors (and have to silently truncate the read ourselves). bcachefs can't use GFP_NOFAIL for folio state unlike iomap based filesystems because our folio state is just barely too big, 2MB hugepages cause us to exceed the 2 page threshhold for GFP_NOFAIL. additionally, the flags argument was just buggy, we weren't supplying GFP_KERNEL previously (!)" * tag 'bcachefs-2024-02-25' of https://evilpiepirate.org/git/bcachefs: bcachefs: fix bch2_save_backtrace() bcachefs: Fix check_snapshot() memcpy bcachefs: Fix bch2_journal_flush_device_pins() bcachefs: fix iov_iter count underflow on sub-block dio read bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btree bcachefs: Kill __GFP_NOFAIL in buffered read path bcachefs: fix backpointer_to_text() when dev does not exist
2024-02-25bcachefs: fix bch2_save_backtrace()Kent Overstreet
Missed a call in the previous fix. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-25Merge tag 'docs-6.8-fixes3' of git://git.lwn.net/linuxLinus Torvalds
Pull two documentation build fixes from Jonathan Corbet: - The XFS online fsck documentation uses incredibly deeply nested subsection and list nesting; that broke the PDF docs build. Tweak a parameter to tell LaTeX to allow the deeper nesting. - Fix a 6.8 PDF-build regression * tag 'docs-6.8-fixes3' of git://git.lwn.net/linux: docs: translations: use attribute to store current language docs: Instruct LaTeX to cope with deeper nesting
2024-02-25Merge tag 'usb-6.8-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB fixes from Greg KH: "Here are some small USB fixes for 6.8-rc6 to resolve some reported problems. These include: - regression fixes with typec tpcm code as reported by many - cdnsp and cdns3 driver fixes - usb role setting code bugfixes - build fix for uhci driver - ncm gadget driver bugfix - MAINTAINERS entry update All of these have been in linux-next all week with no reported issues and there is at least one fix in here that is in Thorsten's regression list that is being tracked" * tag 'usb-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: usb: typec: tpcm: Fix issues with power being removed during reset MAINTAINERS: Drop myself as maintainer of TYPEC port controller drivers usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs Revert "usb: typec: tcpm: reset counter when enter into unattached state after try role" usb: gadget: omap_udc: fix USB gadget regression on Palm TE usb: dwc3: gadget: Don't disconnect if not started usb: cdns3: fix memory double free when handle zero packet usb: cdns3: fixed memory use after free at cdns3_gadget_ep_disable() usb: roles: don't get/set_role() when usb_role_switch is unregistered usb: roles: fix NULL pointer issue when put module's reference usb: cdnsp: fixed issue with incorrect detecting CDNSP family controllers usb: cdnsp: blocked some cdns3 specific code usb: uhci-grlib: Explicitly include linux/platform_device.h
2024-02-25Merge tag 'tty-6.8-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver fixes from Greg KH: "Here are three small serial/tty driver fixes for 6.8-rc6 that resolve the following reported errors: - riscv hvc console driver fix that was reported by many - amba-pl011 serial driver fix for RS485 mode - stm32 serial driver fix for RS485 mode All of these have been in linux-next all week with no reported problems" * tag 'tty-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: amba-pl011: Fix DMA transmission in RS485 mode serial: stm32: do not always set SER_RS485_RX_DURING_TX if RS485 is enabled tty: hvc: Don't enable the RISC-V SBI console by default
2024-02-25Merge tag 'x86_urgent_for_v6.8_rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Make sure clearing CPU buffers using VERW happens at the latest possible point in the return-to-userspace path, otherwise memory accesses after the VERW execution could cause data to land in CPU buffers again * tag 'x86_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: KVM/VMX: Move VERW closer to VMentry for MDS mitigation KVM/VMX: Use BT+JNC, i.e. EFLAGS.CF to select VMRESUME vs. VMLAUNCH x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key x86/entry_32: Add VERW just before userspace transition x86/entry_64: Add VERW just before userspace transition x86/bugs: Add asm helpers for executing VERW
2024-02-25Merge tag 'irq_urgent_for_v6.8_rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Borislav Petkov: - Make sure GICv4 always gets initialized to prevent a kexec-ed kernel from silently failing to set it up - Do not call bus_get_dev_root() for the mbigen irqchip as it always returns NULL - use NULL directly - Fix hardware interrupt number truncation when assigning MSI interrupts - Correct sending end-of-interrupt messages to disabled interrupts lines on RISC-V PLIC * tag 'irq_urgent_for_v6.8_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3-its: Do not assume vPE tables are preallocated irqchip/mbigen: Don't use bus_get_dev_root() to find the parent PCI/MSI: Prevent MSI hardware interrupt number truncation irqchip/sifive-plic: Enable interrupt if needed before EOI
2024-02-25Merge tag 'erofs-for-6.8-rc6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs Pull erofs fix from Gao Xiang: - Fix page refcount leak when looking up specific inodes introduced by metabuf reworking * tag 'erofs-for-6.8-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: fix refcount on the metabuf used for inode lookup
2024-02-25Merge tag 'pull-fixes.pathwalk-rcu-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull RCU pathwalk fixes from Al Viro: "We still have some races in filesystem methods when exposed to RCU pathwalk. This series is a result of code audit (the second round of it) and it should deal with most of that stuff. Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate(). Up to maintainers (a note for NTFS folks - when documentation says that a method may not block, it *does* imply that blocking allocations are to be avoided. Really)" [ More explanations for people who aren't familiar with the vagaries of RCU path walking: most of it is hidden from filesystems, but if a filesystem actively participates in the low-level path walking it needs to make sure the fields involved in that walk are RCU-safe. That "actively participate in low-level path walking" includes things like having its own ->d_hash()/->d_compare() routines, or by having its own directory permission function that doesn't just use the common helpers. Having a ->d_revalidate() function will also have this issue. Note that instead of making everything RCU safe you can also choose to abort the RCU pathwalk if your operation cannot be done safely under RCU, but that obviously comes with a performance penalty. One common pattern is to allow the simple cases under RCU, and abort only if you need to do something more complicated. So not everything needs to be RCU-safe, and things like the inode etc that the VFS itself maintains obviously already are. But these fixes tend to be about properly RCU-delaying things like ->s_fs_info that are maintained by the filesystem and that got potentially released too early. - Linus ] * tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ext4_get_link(): fix breakage in RCU mode cifs_get_link(): bail out in unsafe case fuse: fix UAF in rcu pathwalks procfs: make freeing proc_fs_info rcu-delayed procfs: move dropping pde and pid from ->evict_inode() to ->free_inode() nfs: fix UAF on pathwalk running into umount nfs: make nfs_set_verifier() safe for use in RCU pathwalk afs: fix __afs_break_callback() / afs_drop_open_mmap() race hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper affs: free affs_sb_info with kfree_rcu() rcu pathwalk: prevent bogus hard errors from may_lookup() fs/super.c: don't drop ->s_user_ns until we free struct super_block itself
2024-02-25Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull vfs fixes from Al Viro: "A couple of fixes - revert of regression from this cycle and a fix for erofs failure exit breakage (had been there since way back)" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: erofs: fix handling kern_mount() failure Revert "get rid of DCACHE_GENOCIDE"
2024-02-25ext4_get_link(): fix breakage in RCU modeAl Viro
1) errors from ext4_getblk() should not be propagated to caller unless we are really sure that we would've gotten the same error in non-RCU pathwalk. 2) we leak buffer_heads if ext4_getblk() is successful, but bh is not uptodate. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25cifs_get_link(): bail out in unsafe caseAl Viro
->d_revalidate() bails out there, anyway. It's not enough to prevent getting into ->get_link() in RCU mode, but that could happen only in a very contrieved setup. Not worth trying to do anything fancy here unless ->d_revalidate() stops kicking out of RCU mode at least in some cases. Reviewed-by: Christian Brauner <brauner@kernel.org> Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25fuse: fix UAF in rcu pathwalksAl Viro
->permission(), ->get_link() and ->inode_get_acl() might dereference ->s_fs_info (and, in case of ->permission(), ->s_fs_info->fc->user_ns as well) when called from rcu pathwalk. Freeing ->s_fs_info->fc is rcu-delayed; we need to make freeing ->s_fs_info and dropping ->user_ns rcu-delayed too. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25procfs: make freeing proc_fs_info rcu-delayedAl Viro
makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns() is still synchronous, but that's not a problem - it does rcu-delay everything that needs to be) Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()Al Viro
that keeps both around until struct inode is freed, making access to them safe from rcu-pathwalk Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25nfs: fix UAF on pathwalk running into umountAl Viro
NFS ->d_revalidate(), ->permission() and ->get_link() need to access some parts of nfs_server when called in RCU mode: server->flags server->caps *(server->io_stats) and, worst of all, call server->nfs_client->rpc_ops->have_delegation (the last one - as NFS_PROTO(inode)->have_delegation()). We really don't want to RCU-delay the entire nfs_free_server() (it would have to be done with schedule_work() from RCU callback, since it can't be made to run from interrupt context), but actual freeing of nfs_server and ->io_stats can be done via call_rcu() just fine. nfs_client part is handled simply by making nfs_free_client() use kfree_rcu(). Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25nfs: make nfs_set_verifier() safe for use in RCU pathwalkAl Viro
nfs_set_verifier() relies upon dentry being pinned; if that's the case, grabbing ->d_lock stabilizes ->d_parent and guarantees that ->d_parent points to a positive dentry. For something we'd run into in RCU mode that is *not* true - dentry might've been through dentry_kill() just as we grabbed ->d_lock, with its parent going through the same just as we get to into nfs_set_verifier_locked(). It might get to detaching inode (and zeroing ->d_inode) before nfs_set_verifier_locked() gets to fetching that; we get an oops as the result. That can happen in nfs{,4} ->d_revalidate(); the call chain in question is nfs_set_verifier_locked() <- nfs_set_verifier() <- nfs_lookup_revalidate_delegated() <- nfs{,4}_do_lookup_revalidate(). We have checked that the parent had been positive, but that's done before we get to nfs_set_verifier() and it's possible for memory pressure to pick our dentry as eviction candidate by that time. If that happens, back-to-back attempts to kill dentry and its parent are quite normal. Sure, in case of eviction we'll fail the ->d_seq check in the caller, but we need to survive until we return there... Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25afs: fix __afs_break_callback() / afs_drop_open_mmap() raceAl Viro
In __afs_break_callback() we might check ->cb_nr_mmap and if it's non-zero do queue_work(&vnode->cb_work). In afs_drop_open_mmap() we decrement ->cb_nr_mmap and do flush_work(&vnode->cb_work) if it reaches zero. The trouble is, there's nothing to prevent __afs_break_callback() from seeing ->cb_nr_mmap before the decrement and do queue_work() after both the decrement and flush_work(). If that happens, we might be in trouble - vnode might get freed before the queued work runs. __afs_break_callback() is always done under ->cb_lock, so let's make sure that ->cb_nr_mmap can change from non-zero to zero while holding ->cb_lock (the spinlock component of it - it's a seqlock and we don't need to mess with the counter). Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_infoAl Viro
->d_hash() and ->d_compare() use those, so we need to delay freeing them. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helperAl Viro
That stuff can be accessed by ->d_hash()/->d_compare(); as it is, we have a hard-to-hit UAF if rcu pathwalk manages to get into ->d_hash() on a filesystem that is in process of getting shut down. Besides, having nls and upcase table cleanup moved from ->put_super() towards the place where sbi is freed makes for simpler failure exits. Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25affs: free affs_sb_info with kfree_rcu()Al Viro
one of the flags in it is used by ->d_hash()/->d_compare() Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25rcu pathwalk: prevent bogus hard errors from may_lookup()Al Viro
If lazy call of ->permission() returns a hard error, check that try_to_unlazy() succeeds before returning it. That both makes life easier for ->permission() instances and closes the race in ENOTDIR handling - it is possible that positive d_can_lookup() seen in link_path_walk() applies to the state *after* unlink() + mkdir(), while nd->inode matches the state prior to that. Normally seeing e.g. EACCES from permission check in rcu pathwalk means that with some timings non-rcu pathwalk would've run into the same; however, running into a non-executable regular file in the middle of a pathname would not get to permission check - it would fail with ENOTDIR instead. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25fs/super.c: don't drop ->s_user_ns until we free struct super_block itselfAl Viro
Avoids fun races in RCU pathwalk... Same goes for freeing LSM shite hanging off super_block's arse. Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-24bcachefs: Fix check_snapshot() memcpyKent Overstreet
check_snapshot() copies the bch_snapshot to a temporary to easily handle older versions that don't have all the fields of the current version, but it lacked a min() to correctly handle keys newer and larger than the current version. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24bcachefs: Fix bch2_journal_flush_device_pins()Kent Overstreet
If a journal write errored, the list of devices it was written to could be empty - we're not supposed to mark an empty replicas list. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24bcachefs: fix iov_iter count underflow on sub-block dio readBrian Foster
bch2_direct_IO_read() checks the request offset and size for sector alignment and then falls through to a couple calculations to shrink the size of the request based on the inode size. The problem is that these checks round up to the fs block size, which runs the risk of underflowing iter->count if the block size happens to be large enough. This is triggered by fstest generic/361 with a 4k block size, which subsequently leads to a crash. To avoid this crash, check that the shorten length doesn't exceed the overall length of the iter. Fixes: Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Su Yue <glass.su@suse.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24bcachefs: Fix BTREE_ITER_FILTER_SNAPSHOTS on inodes btreeKent Overstreet
If we're in FILTER_SNAPSHOTS mode and we start scanning a range of the keyspace where no keys are visible in the current snapshot, we have a problem - we'll scan for a very long time before scanning terminates. Awhile back, this was fixed for most cases with peek_upto() (and assertions that enforce that it's being used). But the fix missed the fact that the inodes btree is different - every key offset is in a different snapshot tree, not just the inode field. Fixes: Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24bcachefs: Kill __GFP_NOFAIL in buffered read pathKent Overstreet
Recently, we fixed our __GFP_NOFAIL usage in the readahead path, but the easy one in read_single_folio() (where wa can return an error) was missed - oops. Fixes: Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24bcachefs: fix backpointer_to_text() when dev does not existKent Overstreet
Fixes: Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-02-24Merge tag 'powerpc-6.8-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - Fix a crash when hot adding a PCI device to an LPAR since recent changes - Fix nested KVM level-2 guest reboot failure due to empty 'arch_compat' Thanks to Amit Machhiwal, Aneesh Kumar K.V (IBM), Brian King, Gaurav Batra, and Vaibhav Jain. * tag 'powerpc-6.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: KVM: PPC: Book3S HV: Fix L2 guest reboot failure due to empty 'arch_compat' powerpc/pseries/iommu: DLPAR add doesn't completely initialize pci_controller
2024-02-24Merge tag 'iommu-fixes-v6.8-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu fixes from Joerg Roedel: - Intel VT-d fixes for nested domain handling: - Cache invalidation for changes in a parent domain - Dirty tracking setting for parent and nested domains - Fix a constant-out-of-range warning - ARM SMMU fixes: - Fix CD allocation from atomic context when using SVA with SMMUv3 - Revert the conversion of SMMUv2 to domain_alloc_paging(), as it breaks the boot for Qualcomm MSM8996 devices - Restore SVA handle sharing in core code as it turned out there are still drivers relying on it * tag 'iommu-fixes-v6.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/sva: Restore SVA handle sharing iommu/arm-smmu-v3: Do not use GFP_KERNEL under as spinlock iommu/vt-d: Fix constant-out-of-range warning iommu/vt-d: Set SSADE when attaching to a parent with dirty tracking iommu/vt-d: Add missing dirty tracking set for parent domain iommu/vt-d: Wrap the dirty tracking loop to be a helper iommu/vt-d: Remove domain parameter for intel_pasid_setup_dirty_tracking() iommu/vt-d: Add missing device iotlb flush for parent domain iommu/vt-d: Update iotlb in nested domain attach iommu/vt-d: Add missing iotlb flush for parent domain iommu/vt-d: Add __iommu_flush_iotlb_psi() iommu/vt-d: Track nested domains in parent Revert "iommu/arm-smmu: Convert to domain_alloc_paging()"
2024-02-24Merge tag 'cxl-fixes-6.8-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl fixes from Dan Williams: "A collection of significant fixes for the CXL subsystem. The largest change in this set, that bordered on "new development", is the fix for the fact that the location of the new qos_class attribute did not match the Documentation. The fix ends up deleting more code than it added, and it has a new unit test to backstop basic errors in this interface going forward. So the "red-diff" and unit test saved the "rip it out and try again" response. In contrast, the new notification path for firmware reported CXL errors (CXL CPER notifications) has a locking context bug that can not be fixed with a red-diff. Given where the release cycle stands, it is not comfortable to squeeze in that fix in these waning days. So, that receives the "back it out and try again later" treatment. There is a regression fix in the code that establishes memory NUMA nodes for platform CXL regions. That has an ack from x86 folks. There are a couple more fixups for Linux to understand (reassemble) CXL regions instantiated by platform firmware. The policy around platforms that do not match host-physical-address with system-physical-address (i.e. systems that have an address translation mechanism between the address range reported in the ACPI CEDT.CFMWS and endpoint decoders) has been softened to abort driver load rather than teardown the memory range (can cause system hangs). Lastly, there is a robustness / regression fix for cases where the driver would previously continue in the face of error, and a fixup for PCI error notification handling. Summary: - Fix NUMA initialization from ACPI CEDT.CFMWS - Fix region assembly failures due to async init order - Fix / simplify export of qos_class information - Fix cxl_acpi initialization vs single-window-init failures - Fix handling of repeated 'pci_channel_io_frozen' notifications - Workaround platforms that violate host-physical-address == system-physical address assumptions - Defer CXL CPER notification handling to v6.9" * tag 'cxl-fixes-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/acpi: Fix load failures due to single window creation failure acpi/ghes: Remove CXL CPER notifications cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window cxl/test: Add support for qos_class checking cxl: Fix sysfs export of qos_class for memdev cxl: Remove unnecessary type cast in cxl_qos_class_verify() cxl: Change 'struct cxl_memdev_state' *_perf_list to single 'struct cxl_dpa_perf' cxl/region: Allow out of order assembly of autodiscovered regions cxl/region: Handle endpoint decoders in cxl_region_find_decoder() x86/numa: Fix the sort compare func used in numa_fill_memblks() x86/numa: Fix the address overlap check in numa_fill_memblks() cxl/pci: Skip to handle RAS errors if CXL.mem device is detached