kernel/linux.git/security/integrity/evm, branch v4.14.263

evm: mark evm_fixmode as __ro_after_init

2021-11-26T10:40:23+00:00

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 Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

evm: Fix possible memory leak in evm_calc_hmac_or_hash()

2020-06-20T08:25:15+00:00

commit 0c4395fb2aa77341269ea619c5419ea48171883f upstream. Don't immediately return if the signature is portable and security.ima is not present. Just set error so that memory allocated is freed before returning from evm_calc_hmac_or_hash(). Fixes: 50b977481fce9 ("EVM: Add support for portable signature format") Signed-off-by: Roberto Sassu Cc: stable@vger.kernel.org Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman

evm: Check also if *tfm is an error pointer in init_desc()

2020-05-27T14:42:51+00:00

[ Upstream commit 53de3b080d5eae31d0de219617155dcc34e7d698 ] This patch avoids a kernel panic due to accessing an error pointer set by crypto_alloc_shash(). It occurs especially when there are many files that require an unsupported algorithm, as it would increase the likelihood of the following race condition: Task A: *tfm = crypto_alloc_shash() <= error pointer Task B: if (*tfm == NULL) <= *tfm is not NULL, use it Task B: rc = crypto_shash_init(desc) <= panic Task A: *tfm = NULL This patch uses the IS_ERR_OR_NULL macro to determine whether or not a new crypto context must be created. Cc: stable@vger.kernel.org Fixes: d46eb3699502b ("evm: crypto hash replaced by shash") Co-developed-by: Krzysztof Struczynski Signed-off-by: Krzysztof Struczynski Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

EVM: Add support for portable signature format

2018-12-01T08:43:00+00:00

commit 50b977481fce90aa5fbda55e330b9d722733e358 upstream. The EVM signature includes the inode number and (optionally) the filesystem UUID, making it impractical to ship EVM signatures in packages. This patch adds a new portable format intended to allow distributions to include EVM signatures. It is identical to the existing format but hardcodes the inode and generation numbers to 0 and does not include the filesystem UUID even if the kernel is configured to do so. Removing the inode means that the metadata and signature from one file could be copied to another file without invalidating it. This is avoided by ensuring that an IMA xattr is present during EVM validation. Portable signatures are intended to be immutable - ie, they will never be transformed into HMACs. Based on earlier work by Dmitry Kasatkin and Mikhail Kurinnoi. Signed-off-by: Matthew Garrett Cc: Dmitry Kasatkin Cc: Mikhail Kurinnoi Signed-off-by: Mimi Zohar Cc: Aditya Kali Signed-off-by: Greg Kroah-Hartman

evm: Don't deadlock if a crypto algorithm is unavailable

2018-09-26T06:38:09+00:00

[ Upstream commit e2861fa71641c6414831d628a1f4f793b6562580 ] When EVM attempts to appraise a file signed with a crypto algorithm the kernel doesn't have support for, it will cause the kernel to trigger a module load. If the EVM policy includes appraisal of kernel modules this will in turn call back into EVM - since EVM is holding a lock until the crypto initialisation is complete, this triggers a deadlock. Add a CRYPTO_NOLOAD flag and skip module loading if it's set, and add that flag in the EVM case in order to fail gracefully with an error message instead of deadlocking. Signed-off-by: Matthew Garrett Acked-by: Herbert Xu Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fs: switch ->s_uuid to uuid_t

2017-06-05T14:59:12+00:00

For some file systems we still memcpy into it, but in various places this already allows us to use the proper uuid helpers. More to come.. Signed-off-by: Christoph Hellwig Reviewed-by: Amir Goldstein Acked-by: Mimi Zohar (Changes to IMA/EVM) Reviewed-by: Andy Shevchenko

sched/headers: Prepare to remove the include from

2017-03-02T07:42:40+00:00

Update files that depend on the magic.h inclusion. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2016-12-14T22:09:48+00:00

Pull namespace updates from Eric Biederman: "After a lot of discussion and work we have finally reachanged a basic understanding of what is necessary to make unprivileged mounts safe in the presence of EVM and IMA xattrs which the last commit in this series reflects. While technically it is a revert the comments it adds are important for people not getting confused in the future. Clearing up that confusion allows us to seriously work on unprivileged mounts of fuse in the next development cycle. The rest of the fixes in this set are in the intersection of user namespaces, ptrace, and exec. I started with the first fix which started a feedback cycle of finding additional issues during review and fixing them. Culiminating in a fix for a bug that has been present since at least Linux v1.0. Potentially these fixes were candidates for being merged during the rc cycle, and are certainly backport candidates but enough little things turned up during review and testing that I decided they should be handled as part of the normal development process just to be certain there were not any great surprises when it came time to backport some of these fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC" exec: Ensure mm->user_ns contains the execed files ptrace: Don't allow accessing an undumpable mm ptrace: Capture the ptracer's creds not PT_PTRACE_CAP mm: Add a user_ns owner to mm_struct and fix ptrace permission checks

Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC"

2016-12-03T02:58:41+00:00

This reverts commit 0b3c9761d1e405514a551ed24d3ea89aea26ce14. Seth Forshee writes: > All right, I think 0b3c9761d1e405514a551ed24d3ea89aea26ce14 should be > reverted then. EVM is a machine-local integrity mechanism, and so it > makes sense that the signature would be based on the kernel's notion of > the uid and not the filesystem's. I added a commment explaining why the EVM hmac needs to be in the kernel's notion of uid and gid, not the filesystems to prevent remounting the filesystem and gaining unwaranted trust in files. Acked-by: Seth Forshee Signed-off-by: "Eric W. Biederman"

security/integrity: Harden against malformed xattrs

2016-11-14T03:50:11+00:00

In general the handling of IMA/EVM xattrs is good, but I found a few locations where either the xattr size or the value of the type field in the xattr are not checked. Add a few simple checks to these locations to prevent malformed or malicious xattrs from causing problems. Signed-off-by: Seth Forshee Signed-off-by: Mimi Zohar