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2022-06-14KEYS: trusted: tpm2: Fix migratable logicDavid Safford
commit dda5384313a40ecbaafd8a9a80f47483255e4c4d upstream. When creating (sealing) a new trusted key, migratable trusted keys have the FIXED_TPM and FIXED_PARENT attributes set, and non-migratable keys don't. This is backwards, and also causes creation to fail when creating a migratable key under a migratable parent. (The TPM thinks you are trying to seal a non-migratable blob under a migratable parent.) The following simple patch fixes the logic, and has been tested for all four combinations of migratable and non-migratable trusted keys and parent storage keys. With this logic, you will get a proper failure if you try to create a non-migratable trusted key under a migratable parent storage key, and all other combinations work correctly. Cc: stable@vger.kernel.org # v5.13+ Fixes: e5fb5d2c5a03 ("security: keys: trusted: Make sealed key properly interoperable") Signed-off-by: David Safford <david.safford@gmail.com> Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09ima: remove the IMA_TEMPLATE Kconfig optionGUO Zihua
commit 891163adf180bc369b2f11c9dfce6d2758d2a5bd upstream. The original 'ima' measurement list template contains a hash, defined as 20 bytes, and a null terminated pathname, limited to 255 characters. Other measurement list templates permit both larger hashes and longer pathnames. When the "ima" template is configured as the default, a new measurement list template (ima_template=) must be specified before specifying a larger hash algorithm (ima_hash=) on the boot command line. To avoid this boot command line ordering issue, remove the legacy "ima" template configuration option, allowing it to still be specified on the boot command line. The root cause of this issue is that during the processing of ima_hash, we would try to check whether the hash algorithm is compatible with the template. If the template is not set at the moment we do the check, we check the algorithm against the configured default template. If the default template is "ima", then we reject any hash algorithm other than sha1 and md5. For example, if the compiled default template is "ima", and the default algorithm is sha1 (which is the current default). In the cmdline, we put in "ima_hash=sha256 ima_template=ima-ng". The expected behavior would be that ima starts with ima-ng as the template and sha256 as the hash algorithm. However, during the processing of "ima_hash=", "ima_template=" has not been processed yet, and hash_setup would check the configured hash algorithm against the compiled default: ima, and reject sha256. So at the end, the hash algorithm that is actually used will be sha1. With template "ima" removed from the configured default, we ensure that the default tempalte would at least be "ima-ng" which allows for basically any hash algorithm. This change would not break the algorithm compatibility checks for IMA. Fixes: 4286587dccd43 ("ima: add Kconfig default measurement list template") Signed-off-by: GUO Zihua <guozihua@huawei.com> Cc: <Stable@vger.kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Fix same-layer rule unionsMickaël Salaün
commit 8ba0005ff418ec356e176b26eaa04a6ac755d05b upstream. The original behavior was to check if the full set of requested accesses was allowed by at least a rule of every relevant layer. This didn't take into account requests for multiple accesses and same-layer rules allowing the union of these accesses in a complementary way. As a result, multiple accesses requested on a file hierarchy matching rules that, together, allowed these accesses, but without a unique rule allowing all of them, was illegitimately denied. This case should be rare in practice and it can only be triggered by the path_rename or file_open hook implementations. For instance, if, for the same layer, a rule allows execution beneath /a/b and another rule allows read beneath /a, requesting access to read and execute at the same time for /a/b should be allowed for this layer. This was an inconsistency because the union of same-layer rule accesses was already allowed if requested once at a time anyway. This fix changes the way allowed accesses are gathered over a path walk. To take into account all these rule accesses, we store in a matrix all layer granting the set of requested accesses, according to the handled accesses. To avoid heap allocation, we use an array on the stack which is 2*13 bytes. A following commit bringing the LANDLOCK_ACCESS_FS_REFER access right will increase this size to reach 112 bytes (2*14*4) in case of link or rename actions. Add a new layout1.layer_rule_unions test to check that accesses from different rules pertaining to the same layer are ORed in a file hierarchy. Also test that it is not the case for rules from different layers. Reviewed-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20220506161102.525323-5-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Create find_rule() from unmask_layers()Mickaël Salaün
commit 2cd7cd6eed88b8383cfddce589afe9c0ae1d19b4 upstream. This refactoring will be useful in a following commit. Reviewed-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20220506161102.525323-4-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Reduce the maximum number of layers to 16Mickaël Salaün
commit 75c542d6c6cc48720376862d5496d51509160dfd upstream. The maximum number of nested Landlock domains is currently 64. Because of the following fix and to help reduce the stack size, let's reduce it to 16. This seems large enough for a lot of use cases (e.g. sandboxed init service, spawning a sandboxed SSH service, in nested sandboxed containers). Reducing the number of nested domains may also help to discover misuse of Landlock (e.g. creating a domain per rule). Add and use a dedicated layer_mask_t typedef to fit with the number of layers. This might be useful when changing it and to keep it consistent with the maximum number of layers. Reviewed-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20220506161102.525323-3-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Define access_mask_t to enforce a consistent access mask sizeMickaël Salaün
commit 5f2ff33e10843ef51275c8611bdb7b49537aba5d upstream. Create and use the access_mask_t typedef to enforce a consistent access mask size and uniformly use a 16-bits type. This will helps transition to a 32-bits value one day. Add a build check to make sure all (filesystem) access rights fit in. This will be extended with a following commit. Reviewed-by: Paul Moore <paul@paul-moore.com> Link: https://lore.kernel.org/r/20220506161102.525323-2-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Change landlock_restrict_self(2) check orderingMickaël Salaün
commit eba39ca4b155c54adf471a69e91799cc1727873f upstream. According to the Landlock goal to be a security feature available to unprivileges processes, it makes more sense to first check for no_new_privs before checking anything else (i.e. syscall arguments). Merge inval_fd_enforce and unpriv_enforce_without_no_new_privs tests into the new restrict_self_checks_ordering. This is similar to the previous commit checking other syscalls. Link: https://lore.kernel.org/r/20220506160820.524344-10-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Change landlock_add_rule(2) argument check orderingMickaël Salaün
commit 589172e5636c4d16c40b90e87543d43defe2d968 upstream. This makes more sense to first check the ruleset FD and then the rule attribute. It will be useful to factor out code for other rule types. Add inval_add_rule_arguments tests, extension of empty_path_beneath_attr tests, to also check error ordering for landlock_add_rule(2). Link: https://lore.kernel.org/r/20220506160820.524344-9-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Fix landlock_add_rule(2) documentationMickaël Salaün
commit a13e248ff90e81e9322406c0e618cf2168702f4e upstream. It is not mandatory to pass a file descriptor obtained with the O_PATH flag. Also, replace rule's accesses with ruleset's accesses. Link: https://lore.kernel.org/r/20220506160820.524344-2-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Format with clang-formatMickaël Salaün
commit 06a1c40a09a8dded4bf0e7e3ccbda6bddcccd7c8 upstream. Let's follow a consistent and documented coding style. Everything may not be to our liking but it is better than tacit knowledge. Moreover, this will help maintain style consistency between different developers. This contains only whitespace changes. Automatically formatted with: clang-format-14 -i security/landlock/*.[ch] include/uapi/linux/landlock.h Link: https://lore.kernel.org/r/20220506160513.523257-3-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09landlock: Add clang-format exceptionsMickaël Salaün
commit 6cc2df8e3a3967e7c13a424f87f6efb1d4a62d80 upstream. In preparation to a following commit, add clang-format on and clang-format off stanzas around constant definitions. This enables to keep aligned values, which is much more readable than packed definitions. Link: https://lore.kernel.org/r/20220506160513.523257-2-mic@digikod.net Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09efi: Do not import certificates from UEFI Secure Boot for T2 MacsAditya Garg
commit 155ca952c7ca19aa32ecfb7373a32bbc2e1ec6eb upstream. On Apple T2 Macs, when Linux attempts to read the db and dbx efi variables at early boot to load UEFI Secure Boot certificates, a page fault occurs in Apple firmware code and EFI runtime services are disabled with the following logs: [Firmware Bug]: Page fault caused by firmware at PA: 0xffffb1edc0068000 WARNING: CPU: 3 PID: 104 at arch/x86/platform/efi/quirks.c:735 efi_crash_gracefully_on_page_fault+0x50/0xf0 (Removed some logs from here) Call Trace: <TASK> page_fault_oops+0x4f/0x2c0 ? search_bpf_extables+0x6b/0x80 ? search_module_extables+0x50/0x80 ? search_exception_tables+0x5b/0x60 kernelmode_fixup_or_oops+0x9e/0x110 __bad_area_nosemaphore+0x155/0x190 bad_area_nosemaphore+0x16/0x20 do_kern_addr_fault+0x8c/0xa0 exc_page_fault+0xd8/0x180 asm_exc_page_fault+0x1e/0x30 (Removed some logs from here) ? __efi_call+0x28/0x30 ? switch_mm+0x20/0x30 ? efi_call_rts+0x19a/0x8e0 ? process_one_work+0x222/0x3f0 ? worker_thread+0x4a/0x3d0 ? kthread+0x17a/0x1a0 ? process_one_work+0x3f0/0x3f0 ? set_kthread_struct+0x40/0x40 ? ret_from_fork+0x22/0x30 </TASK> ---[ end trace 1f82023595a5927f ]--- efi: Froze efi_rts_wq and disabled EFI Runtime Services integrity: Couldn't get size: 0x8000000000000015 integrity: MODSIGN: Couldn't get UEFI db list efi: EFI Runtime Services are disabled! integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get UEFI dbx list integrity: Couldn't get size: 0x8000000000000015 integrity: Couldn't get mokx list integrity: Couldn't get size: 0x80000000 So we avoid reading these UEFI variables and thus prevent the crash. Cc: stable@vger.kernel.org Signed-off-by: Aditya Garg <gargaditya08@live.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25lockdown: also lock down previous kgdb useDaniel Thompson
commit eadb2f47a3ced5c64b23b90fd2a3463f63726066 upstream. KGDB and KDB allow read and write access to kernel memory, and thus should be restricted during lockdown. An attacker with access to a serial port (for example, via a hypervisor console, which some cloud vendors provide over the network) could trigger the debugger so it is important that the debugger respect the lockdown mode when/if it is triggered. Fix this by integrating lockdown into kdb's existing permissions mechanism. Unfortunately kgdb does not have any permissions mechanism (although it certainly could be added later) so, for now, kgdb is simply and brutally disabled by immediately exiting the gdb stub without taking any action. For lockdowns established early in the boot (e.g. the normal case) then this should be fine but on systems where kgdb has set breakpoints before the lockdown is enacted than "bad things" will happen. CVE: CVE-2022-21499 Co-developed-by: Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-25selinux: fix bad cleanup on error in hashtab_duplicate()Ondrej Mosnacek
commit 6254bd3db316c9ccb3b05caa8b438be63245466f upstream. The code attempts to free the 'new' pointer using kmem_cache_free(), which is wrong because this function isn't responsible of freeing it. Instead, the function should free new->htable and clear the contents of *new (to prevent double-free). Cc: stable@vger.kernel.org Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Reported-by: Wander Lairson Costa <wander@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08Fix incorrect type in assignment of ipv6 port for auditCasey Schaufler
[ Upstream commit a5cd1ab7ab679d252a6d2f483eee7d45ebf2040c ] Remove inappropriate use of ntohs() and assign the port value directly. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: allow FIOCLEX and FIONCLEX with policy capabilityRichard Haines
[ Upstream commit 65881e1db4e948614d9eb195b8e1197339822949 ] These ioctls are equivalent to fcntl(fd, F_SETFD, flags), which SELinux always allows too. Furthermore, a failed FIOCLEX could result in a file descriptor being leaked to a process that should not have access to it. As this patch removes access controls, a policy capability needs to be enabled in policy to always allow these ioctls. Based-on-patch-by: Demi Marie Obenour <demiobenour@gmail.com> Signed-off-by: Richard Haines <richard_c_haines@btinternet.com> [PM: subject line tweak] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: use correct type for context lengthChristian Göttsche
[ Upstream commit b97df7c098c531010e445da88d02b7bf7bf59ef6 ] security_sid_to_context() expects a pointer to an u32 as the address where to store the length of the computed context. Reported by sparse: security/selinux/xfrm.c:359:39: warning: incorrect type in arg 4 (different signedness) security/selinux/xfrm.c:359:39: expected unsigned int [usertype] *scontext_len security/selinux/xfrm.c:359:39: got int * Signed-off-by: Christian Göttsche <cgzones@googlemail.com> [PM: wrapped commit description] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08LSM: general protection fault in legacy_parse_paramCasey Schaufler
[ Upstream commit ecff30575b5ad0eda149aadad247b7f75411fd47 ] The usual LSM hook "bail on fail" scheme doesn't work for cases where a security module may return an error code indicating that it does not recognize an input. In this particular case Smack sees a mount option that it recognizes, and returns 0. A call to a BPF hook follows, which returns -ENOPARAM, which confuses the caller because Smack has processed its data. The SELinux hook incorrectly returns 1 on success. There was a time when this was correct, however the current expectation is that it return 0 on success. This is repaired. Reported-by: syzbot+d1e3b1d92d25abf97943@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08TOMOYO: fix __setup handlers return valuesRandy Dunlap
[ Upstream commit 39844b7e3084baecef52d1498b5fa81afa2cefa9 ] __setup() handlers should return 1 if the parameter is handled. Returning 0 causes the entire string to be added to init's environment strings (limited to 32 strings), unnecessarily polluting it. Using the documented strings "TOMOYO_loader=string1" and "TOMOYO_trigger=string2" causes an Unknown parameter message: Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5 TOMOYO_loader=string1 \ TOMOYO_trigger=string2", will be passed to user space. and these strings are added to init's environment string space: Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 TOMOYO_loader=string1 TOMOYO_trigger=string2 With this change, these __setup handlers act as expected, and init's environment is not polluted with these strings. Fixes: 0e4ae0e0dec63 ("TOMOYO: Make several options configurable.") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Link: https://lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Cc: James Morris <jmorris@namei.org> Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: tomoyo-dev-en@lists.osdn.me Cc: "Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08KEYS: trusted: Avoid calling null function trusted_key_exitDave Kleikamp
[ Upstream commit c5d1ed846e15090bc90dfdaafc07eac066e070bb ] If one loads and unloads the trusted module, trusted_key_exit can be NULL. Call it through static_call_cond() to avoid a kernel trap. Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework") Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Cc: Sumit Garg <sumit.garg@linaro.org> Cc: James Bottomley <jejb@linux.ibm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-integrity@vger.kernel.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08KEYS: trusted: Fix trusted key backends when building as moduleAndreas Rammhold
[ Upstream commit 969a26446bcd142faedfe8c6f41cd7668596c1fa ] Before this commit the kernel could end up with no trusted key sources even though both of the currently supported backends (TPM and TEE) were compiled as modules. This manifested in the trusted key type not being registered at all. When checking if a CONFIG_… preprocessor variable is defined we only test for the builtin (=y) case and not the module (=m) case. By using the IS_REACHABLE() macro we do test for both cases. Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework") Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Reviewed-by: Sumit Garg <sumit.garg@linaro.org> Signed-off-by: Andreas Rammhold <andreas@rammhold.de> Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08EVM: fix the evm= __setup handler return valueRandy Dunlap
[ Upstream commit f2544f5e6c691679d56bb38637d2f347075b36fa ] __setup() handlers should return 1 if the parameter is handled. Returning 0 causes the entire string to be added to init's environment strings (limited to 32 strings), unnecessarily polluting it. Using the documented string "evm=fix" causes an Unknown parameter message: Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc5 evm=fix", will be passed to user space. and that string is added to init's environment string space: Run /sbin/init as init process with arguments: /sbin/init with environment: HOME=/ TERM=linux BOOT_IMAGE=/boot/bzImage-517rc5 evm=fix With this change, using "evm=fix" acts as expected and an invalid option ("evm=evm") causes a warning to be printed: evm: invalid "evm" mode but init's environment is not polluted with this string, as expected. Fixes: 7102ebcd65c1 ("evm: permit only valid security.evm xattrs to be updated") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru> Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: Fix selinux_sb_mnt_opts_compat()Scott Mayhew
[ Upstream commit b8b87fd954b4b1bdd2d739c8f50bf685351a1a94 ] selinux_sb_mnt_opts_compat() is called under the sb_lock spinlock and shouldn't be performing any memory allocations. Fix this by parsing the sids at the same time we're chopping up the security mount options string and then using the pre-parsed sids when doing the comparison. Fixes: cc274ae7763d ("selinux: fix sleeping function called from invalid context") Fixes: 69c4a42d72eb ("lsm,selinux: add new hook to compare new mount to an existing mount") Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: check return value of sel_make_avc_filesChristian Göttsche
[ Upstream commit bcb62828e3e8c813b6613db6eb7fd9657db248fc ] sel_make_avc_files() might fail and return a negative errno value on memory allocation failures. Re-add the check of the return value, dropped in 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table"). Reported by clang-analyzer: security/selinux/selinuxfs.c:2129:2: warning: Value stored to 'ret' is never read [deadcode.DeadStores] ret = sel_make_avc_files(dentry); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table") Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> [PM: description line wrapping, added proper commit ref] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08selinux: access superblock_security_struct in LSM blob wayGONG, Ruiqi
[ Upstream commit 0266c25e7c2821181b610595df42cbca6bc93cb8 ] LSM blob has been involved for superblock's security struct. So fix the remaining direct access to sb->s_security by using the LSM blob mechanism. Fixes: 08abe46b2cfc ("selinux: fall back to SECURITY_FS_USE_GENFS if no xattr support") Fixes: 69c4a42d72eb ("lsm,selinux: add new hook to compare new mount to an existing mount") Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08landlock: Use square brackets around "landlock-ruleset"Christian Brauner
commit aea0b9f2486da8497f35c7114b764bf55e17c7ea upstream. Make the name of the anon inode fd "[landlock-ruleset]" instead of "landlock-ruleset". This is minor but most anon inode fds already carry square brackets around their name: [eventfd] [eventpoll] [fanotify] [fscontext] [io_uring] [pidfd] [signalfd] [timerfd] [userfaultfd] For the sake of consistency lets do the same for the landlock-ruleset anon inode fd that comes with landlock. We did the same in 1cdc415f1083 ("uapi, fsopen: use square brackets around "fscontext" [ver #2]") for the new mount api. Cc: linux-security-module@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20211011133704.1704369-1-brauner@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08KEYS: fix length validation in keyctl_pkey_params_get_2()Eric Biggers
commit c51abd96837f600d8fd940b6ab8e2da578575504 upstream. In many cases, keyctl_pkey_params_get_2() is validating the user buffer lengths against the wrong algorithm properties. Fix it to check against the correct properties. Probably this wasn't noticed before because for all asymmetric keys of the "public_key" subtype, max_data_size == max_sig_size == max_enc_size == max_dec_size. However, this isn't necessarily true for the "asym_tpm" subtype (it should be, but it's not strictly validated). Of course, future key types could have different values as well. Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]") Cc: <stable@vger.kernel.org> # v4.20+ Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02selinux: fix misuse of mutex_is_locked()Ondrej Mosnacek
commit ce2fc710c9d2b25afc710f49bb2065b4439a62bc upstream. mutex_is_locked() tests whether the mutex is locked *by any task*, while here we want to test if it is held *by the current task*. To avoid false/missed WARNINGs, use lockdep_assert_is_held() and lockdep_assert_is_not_held() instead, which do the right thing (though they are a no-op if CONFIG_LOCKDEP=n). Cc: stable@vger.kernel.org Fixes: 2554a48f4437 ("selinux: measure state and policy capabilities") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: Do not print policy rule with inactive LSM labelsStefan Berger
commit 89677197ae709eb1ab3646952c44f6a171c9e74c upstream. Before printing a policy rule scan for inactive LSM labels in the policy rule. Inactive LSM labels are identified by args_p != NULL and rule == NULL. Fixes: 483ec26eed42 ("ima: ima/lsm policy rule loading logic bug fixes") Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Cc: <stable@vger.kernel.org> # v5.6+ Acked-by: Christian Brauner <brauner@kernel.org> [zohar@linux.ibm.com: Updated "Fixes" tag] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: Allow template selection with ima_template[_fmt]= after ima_hash=Roberto Sassu
commit bb8e52e4906f148c2faf6656b5106cf7233e9301 upstream. Commit c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt") introduced an additional check on the ima_template variable to avoid multiple template selection. Unfortunately, ima_template could be also set by the setup function of the ima_hash= parameter, when it calls ima_template_desc_current(). This causes attempts to choose a new template with ima_template= or with ima_template_fmt=, after ima_hash=, to be ignored. Achieve the goal of the commit mentioned with the new static variable template_setup_done, so that template selection requests after ima_hash= are not ignored. Finally, call ima_init_template_list(), if not already done, to initialize the list of templates before lookup_template_desc() is called. Reported-by: Guo Zihua <guozihua@huawei.com> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Cc: stable@vger.kernel.org Fixes: c2426d2ad5027 ("ima: added support for new kernel cmdline parameter ima_template_fmt") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: Remove ima_policy file before directoryStefan Berger
commit f7333b9572d0559e00352a926c92f29f061b4569 upstream. The removal of ima_dir currently fails since ima_policy still exists, so remove the ima_policy file before removing the directory. Fixes: 4af4662fa4a9 ("integrity: IMA policy") Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Cc: <stable@vger.kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16ima: fix reference leak in asymmetric_verify()Eric Biggers
commit 926fd9f23b27ca6587492c3f58f4c7f4cd01dad5 upstream. Don't leak a reference to the key if its algorithm is unknown. Fixes: 947d70597236 ("ima: Support EC keys for signature verification") Cc: <stable@vger.kernel.org> # v5.13+ Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16integrity: check the return value of audit_log_start()Xiaoke Wang
commit 83230351c523b04ff8a029a4bdf97d881ecb96fc upstream. audit_log_start() returns audit_buffer pointer on success or NULL on error, so it is better to check the return value of it. Fixes: 3323eec921ef ("integrity: IMA as an integrity service provider") Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com> Cc: <stable@vger.kernel.org> Reviewed-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08selinux: fix double free of cond_list on error pathsVratislav Bendel
commit 186edf7e368c40d06cf727a1ad14698ea67b74ad upstream. On error path from cond_read_list() and duplicate_policydb_cond_list() the cond_list_destroy() gets called a second time in caller functions, resulting in NULL pointer deref. Fix this by resetting the cond_list_len to 0 in cond_list_destroy(), making subsequent calls a noop. Also consistently reset the cond_list pointer to NULL after freeing. Cc: stable@vger.kernel.org Signed-off-by: Vratislav Bendel <vbendel@redhat.com> [PM: fix line lengths in the description] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27selinux: fix potential memleak in selinux_add_opt()Bernard Zhao
[ Upstream commit 2e08df3c7c4e4e74e3dd5104c100f0bf6288aaa8 ] This patch try to fix potential memleak in error branch. Fixes: ba6418623385 ("selinux: new helper - selinux_add_opt()") Signed-off-by: Bernard Zhao <bernard@vivo.com> [PM: tweak the subject line, add Fixes tag] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05selinux: initialize proto variable in selinux_ip_postroute_compat()Tom Rix
commit 732bc2ff080c447f8524f40c970c481f5da6eed3 upstream. Clang static analysis reports this warning hooks.c:5765:6: warning: 4th function call argument is an uninitialized value if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ selinux_parse_skb() can return ok without setting proto. The later call to selinux_xfrm_postroute_last() does an early check of proto and can return ok if the garbage proto value matches. So initialize proto. Cc: stable@vger.kernel.org Fixes: eef9b41622f2 ("selinux: cleanup selinux_xfrm_sock_rcv_skb() and selinux_xfrm_postroute_last()") Signed-off-by: Tom Rix <trix@redhat.com> [PM: typo/spelling and checkpatch.pl description fixes] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-05tomoyo: use hwight16() in tomoyo_domain_quota_is_ok()Tetsuo Handa
[ Upstream commit f702e1107601230eec707739038a89018ea3468d ] hwight16() is much faster. While we are at it, no need to include "perm =" part into data_race() macro, for perm is a local variable that cannot be accessed by other threads. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-05tomoyo: Check exceeded quota early in tomoyo_domain_quota_is_ok().Dmitry Vyukov
[ Upstream commit 04e57a2d952bbd34bc45744e72be3eecdc344294 ] If tomoyo is used in a testing/fuzzing environment in learning mode, for lots of domains the quota will be exceeded and stay exceeded for prolonged periods of time. In such cases it's pointless (and slow) to walk the whole acl list again and again just to rediscover that the quota is exceeded. We already have the TOMOYO_DIF_QUOTA_WARNED flag that notes the overflow condition. Check it early to avoid the slowdown. [penguin-kernel] This patch causes a user visible change that the learning mode will not be automatically resumed after the quota is increased. To resume the learning mode, administrator will need to explicitly clear TOMOYO_DIF_QUOTA_WARNED flag after increasing the quota. But I think that this change is generally preferable, for administrator likely wants to optimize the acl list for that domain before increasing the quota, or that domain likely hits the quota again. Therefore, don't try to care to clear TOMOYO_DIF_QUOTA_WARNED flag automatically when the quota for that domain changed. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-22selinux: fix sleeping function called from invalid contextScott Mayhew
commit cc274ae7763d9700a56659f3228641d7069e7a3f upstream. selinux_sb_mnt_opts_compat() is called via sget_fc() under the sb_lock spinlock, so it can't use GFP_KERNEL allocations: [ 868.565200] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:230 [ 868.568246] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 4914, name: mount.nfs [ 868.569626] preempt_count: 1, expected: 0 [ 868.570215] RCU nest depth: 0, expected: 0 [ 868.570809] Preemption disabled at: [ 868.570810] [<0000000000000000>] 0x0 [ 868.571848] CPU: 1 PID: 4914 Comm: mount.nfs Kdump: loaded Tainted: G W 5.16.0-rc5.2585cf9dfa #1 [ 868.573273] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-4.fc34 04/01/2014 [ 868.574478] Call Trace: [ 868.574844] <TASK> [ 868.575156] dump_stack_lvl+0x34/0x44 [ 868.575692] __might_resched.cold+0xd6/0x10f [ 868.576308] slab_pre_alloc_hook.constprop.0+0x89/0xf0 [ 868.577046] __kmalloc_track_caller+0x72/0x420 [ 868.577684] ? security_context_to_sid_core+0x48/0x2b0 [ 868.578569] kmemdup_nul+0x22/0x50 [ 868.579108] security_context_to_sid_core+0x48/0x2b0 [ 868.579854] ? _nfs4_proc_pathconf+0xff/0x110 [nfsv4] [ 868.580742] ? nfs_reconfigure+0x80/0x80 [nfs] [ 868.581355] security_context_str_to_sid+0x36/0x40 [ 868.581960] selinux_sb_mnt_opts_compat+0xb5/0x1e0 [ 868.582550] ? nfs_reconfigure+0x80/0x80 [nfs] [ 868.583098] security_sb_mnt_opts_compat+0x2a/0x40 [ 868.583676] nfs_compare_super+0x113/0x220 [nfs] [ 868.584249] ? nfs_try_mount_request+0x210/0x210 [nfs] [ 868.584879] sget_fc+0xb5/0x2f0 [ 868.585267] nfs_get_tree_common+0x91/0x4a0 [nfs] [ 868.585834] vfs_get_tree+0x25/0xb0 [ 868.586241] fc_mount+0xe/0x30 [ 868.586605] do_nfs4_mount+0x130/0x380 [nfsv4] [ 868.587160] nfs4_try_get_tree+0x47/0xb0 [nfsv4] [ 868.587724] vfs_get_tree+0x25/0xb0 [ 868.588193] do_new_mount+0x176/0x310 [ 868.588782] __x64_sys_mount+0x103/0x140 [ 868.589388] do_syscall_64+0x3b/0x90 [ 868.589935] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 868.590699] RIP: 0033:0x7f2b371c6c4e [ 868.591239] Code: 48 8b 0d dd 71 0e 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d aa 71 0e 00 f7 d8 64 89 01 48 [ 868.593810] RSP: 002b:00007ffc83775d88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 [ 868.594691] RAX: ffffffffffffffda RBX: 00007ffc83775f10 RCX: 00007f2b371c6c4e [ 868.595504] RDX: 0000555d517247a0 RSI: 0000555d51724700 RDI: 0000555d51724540 [ 868.596317] RBP: 00007ffc83775f10 R08: 0000555d51726890 R09: 0000555d51726890 [ 868.597162] R10: 0000000000000000 R11: 0000000000000246 R12: 0000555d51726890 [ 868.598005] R13: 0000000000000003 R14: 0000555d517246e0 R15: 0000555d511ac925 [ 868.598826] </TASK> Cc: stable@vger.kernel.org Fixes: 69c4a42d72eb ("lsm,selinux: add new hook to compare new mount to an existing mount") Signed-off-by: Scott Mayhew <smayhew@redhat.com> [PM: cleanup/line-wrap the backtrace] Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-25selinux: fix NULL-pointer dereference when hashtab allocation failsOndrej Mosnacek
commit dc27f3c5d10c58069672215787a96b4fae01818b upstream. When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails. Cc: stable@vger.kernel.org Fixes: 03414a49ad5f ("selinux: do not allocate hashtabs dynamically") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-21fortify: Explicitly disable Clang supportKees Cook
commit a52f8a59aef46b59753e583bf4b28fccb069ce64 upstream. Clang has never correctly compiled the FORTIFY_SOURCE defenses due to a couple bugs: Eliding inlines with matching __builtin_* names https://bugs.llvm.org/show_bug.cgi?id=50322 Incorrect __builtin_constant_p() of some globals https://bugs.llvm.org/show_bug.cgi?id=41459 In the process of making improvements to the FORTIFY_SOURCE defenses, the first (silent) bug (coincidentally) becomes worked around, but exposes the latter which breaks the build. As such, Clang must not be used with CONFIG_FORTIFY_SOURCE until at least latter bug is fixed (in Clang 13), and the fortify routines have been rearranged. Update the Kconfig to reflect the reality of the current situation. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/lkml/CAKwvOd=A+ueGV2ihdy5GtgR2fQbcXjjAtVxv3=cPjffpebZB7A@mail.gmail.com Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18apparmor: fix error checkTom Rix
[ Upstream commit d108370c644b153382632b3e5511ade575c91c86 ] clang static analysis reports this representative problem: label.c:1463:16: warning: Assigned value is garbage or undefined label->hname = name; ^ ~~~~ In aa_update_label_name(), this the problem block of code if (aa_label_acntsxprint(&name, ...) == -1) return res; On failure, aa_label_acntsxprint() has a more complicated return that just -1. So check for a negative return. It was also noted that the aa_label_acntsxprint() main comment refers to a nonexistent parameter, so clean up the comment. Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels") Signed-off-by: Tom Rix <trix@redhat.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18smackfs: use netlbl_cfg_cipsov4_del() for deleting cipso_v4_doiTetsuo Handa
[ Upstream commit 0934ad42bb2c5df90a1b9de690f93de735b622fe ] syzbot is reporting UAF at cipso_v4_doi_search() [1], for smk_cipso_doi() is calling kfree() without removing from the cipso_v4_doi_list list after netlbl_cfg_cipsov4_map_add() returned an error. We need to use netlbl_cfg_cipsov4_del() in order to remove from the list and wait for RCU grace period before kfree(). Link: https://syzkaller.appspot.com/bug?extid=93dba5b91f0fed312cbd [1] Reported-by: syzbot <syzbot+93dba5b91f0fed312cbd@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: 6c2e8ac0953fccdd ("netlabel: Update kernel configuration API") Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18ima: fix deadlock when traversing "ima_default_rules".liqiong
[ Upstream commit eb0782bbdfd0d7c4786216659277c3fd585afc0e ] The current IMA ruleset is identified by the variable "ima_rules" that default to "&ima_default_rules". When loading a custom policy for the first time, the variable is updated to "&ima_policy_rules" instead. That update isn't RCU-safe, and deadlocks are possible. Indeed, some functions like ima_match_policy() may loop indefinitely when traversing "ima_default_rules" with list_for_each_entry_rcu(). When iterating over the default ruleset back to head, if the list head is "ima_default_rules", and "ima_rules" have been updated to "&ima_policy_rules", the loop condition (&entry->list != ima_rules) stays always true, traversing won't terminate, causing a soft lockup and RCU stalls. Introduce a temporary value for "ima_rules" when iterating over the ruleset to avoid the deadlocks. Signed-off-by: liqiong <liqiong@nfschina.com> Reviewed-by: THOBY Simon <Simon.THOBY@viveris.fr> Fixes: 38d859f991f3 ("IMA: policy can now be updated multiple times") Reported-by: kernel test robot <lkp@intel.com> (Fix sparse: incompatible types in comparison expression.) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18smackfs: use __GFP_NOFAIL for smk_cipso_doi()Tetsuo Handa
[ Upstream commit f91488ee15bd3cac467e2d6a361fc2d34d1052ae ] syzbot is reporting kernel panic at smk_cipso_doi() due to memory allocation fault injection [1]. The reason for need to use panic() was not explained. But since no fix was proposed for 18 months, for now let's use __GFP_NOFAIL for utilizing syzbot resource on other bugs. Link: https://syzkaller.appspot.com/bug?extid=89731ccb6fec15ce1c22 [1] Reported-by: syzbot <syzbot+89731ccb6fec15ce1c22@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18smackfs: Fix use-after-free in netlbl_catmap_walk()Pawan Gupta
[ Upstream commit 0817534ff9ea809fac1322c5c8c574be8483ea57 ] Syzkaller reported use-after-free bug as described in [1]. The bug is triggered when smk_set_cipso() tries to free stale category bitmaps while there are concurrent reader(s) using the same bitmaps. Wait for RCU grace period to finish before freeing the category bitmaps in smk_set_cipso(). This makes sure that there are no more readers using the stale bitmaps and freeing them should be safe. [1] https://lore.kernel.org/netdev/000000000000a814c505ca657a4e@google.com/ Reported-by: syzbot+3f91de0b813cc3d19a80@syzkaller.appspotmail.com Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18evm: mark evm_fixmode as __ro_after_initAustin Kim
commit 32ba540f3c2a7ef61ed5a577ce25069a3d714fc9 upstream. The evm_fixmode is only configurable by command-line option and it is never modified outside initcalls, so declaring it with __ro_after_init is better. Signed-off-by: Austin Kim <austin.kim@lge.com> Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-18selinux: fix race condition when computing ocontext SIDsOndrej Mosnacek
commit cbfcd13be5cb2a07868afe67520ed181956579a7 upstream. Current code contains a lot of racy patterns when converting an ocontext's context structure to an SID. This is being done in a "lazy" fashion, such that the SID is looked up in the SID table only when it's first needed and then cached in the "sid" field of the ocontext structure. However, this is done without any locking or memory barriers and is thus unsafe. Between commits 24ed7fdae669 ("selinux: use separate table for initial SID lookup") and 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table"), this race condition lead to an actual observable bug, because a pointer to the shared sid field was passed directly to sidtab_context_to_sid(), which was using this location to also store an intermediate value, which could have been read by other threads and interpreted as an SID. In practice this caused e.g. new mounts to get a wrong (seemingly random) filesystem context, leading to strange denials. This bug has been spotted in the wild at least twice, see [1] and [2]. Fix the race condition by making all the racy functions use a common helper that ensures the ocontext::sid accesses are made safely using the appropriate SMP constructs. Note that security_netif_sid() was populating the sid field of both contexts stored in the ocontext, but only the first one was actually used. The SELinux wiki's documentation on the "netifcon" policy statement [3] suggests that using only the first context is intentional. I kept only the handling of the first context here, as there is really no point in doing the SID lookup for the unused one. I wasn't able to reproduce the bug mentioned above on any kernel that includes commit 66f8e2f03c02, even though it has been reported that the issue occurs with that commit, too, just less frequently. Thus, I wasn't able to verify that this patch fixes the issue, but it makes sense to avoid the race condition regardless. [1] https://github.com/containers/container-selinux/issues/89 [2] https://lists.fedoraproject.org/archives/list/selinux@lists.fedoraproject.org/thread/6DMTAMHIOAOEMUAVTULJD45JZU7IBAFM/ [3] https://selinuxproject.org/page/NetworkStatements#netifcon Cc: stable@vger.kernel.org Cc: Xinjie Zheng <xinjie@google.com> Reported-by: Sujithra Periasamy <sujithra@google.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-12binder: use cred instead of task for selinux checksTodd Kjos
commit 52f88693378a58094c538662ba652aff0253c4fe upstream. Since binder was integrated with selinux, it has passed 'struct task_struct' associated with the binder_proc to represent the source and target of transactions. The conversion of task to SID was then done in the hook implementations. It turns out that there are race conditions which can result in an incorrect security context being used. Fix by using the 'struct cred' saved during binder_open and pass it to the selinux subsystem. Cc: stable@vger.kernel.org # 5.14 (need backport for earlier stables) Fixes: 79af73079d75 ("Add security hooks to binder and implement the hooks for SELinux.") Suggested-by: Jann Horn <jannh@google.com> Signed-off-by: Todd Kjos <tkjos@google.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-21Merge branch 'ucount-fixes-for-v5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull ucounts fixes from Eric Biederman: "There has been one very hard to track down bug in the ucount code that we have been tracking since roughly v5.14 was released. Alex managed to find a reliable reproducer a few days ago and then I was able to instrument the code and figure out what the issue was. It turns out the sigqueue_alloc single atomic operation optimization did not play nicely with ucounts multiple level rlimits. It turned out that either sigqueue_alloc or sigqueue_free could be operating on multiple levels and trigger the conditions for the optimization on more than one level at the same time. To deal with that situation I have introduced inc_rlimit_get_ucounts and dec_rlimit_put_ucounts that just focuses on the optimization and the rlimit and ucount changes. While looking into the big bug I found I couple of other little issues so I am including those fixes here as well. When I have time I would very much like to dig into process ownership of the shared signal queue and see if we could pick a single owner for the entire queue so that all of the rlimits can count to that owner. That should entirely remove the need to call get_ucounts and put_ucounts in sigqueue_alloc and sigqueue_free. It is difficult because Linux unlike POSIX supports setuid that works on a single thread" * 'ucount-fixes-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ucounts: Move get_ucounts from cred_alloc_blank to key_change_session_keyring ucounts: Proper error handling in set_cred_ucounts ucounts: Pair inc_rlimit_ucounts with dec_rlimit_ucoutns in commit_creds ucounts: Fix signal ucount refcounting