kernel/linux.git/security/apparmor/include/policy_unpack.h, branch v7.1.6

apparmor: fix use-after-free in rawdata dedup loop

2026-07-04T11:45:03+00:00

commit 6f060496d03e4dc560a40f73770bd08335cb7a27 upstream. aa_replace_profiles() walks ns->rawdata_list to dedup the incoming policy blob against entries already attached to existing profiles. Per the kernel-doc on struct aa_loaddata, list membership does not hold a reference: profiles hold pcount, and when the last pcount drops, do_ploaddata_rmfs() is queued on a workqueue that takes ns->lock and removes the entry. Between dropping the last pcount and the workqueue running, an entry remains on the list with pcount == 0. aa_get_profile_loaddata() is an unconditional kref_get() on pcount, so when the dedup loop hits such an entry, refcount hardening reports refcount_t: addition on 0; use-after-free. inside aa_replace_profiles(), and the poisoned counter then trips "saturated" and "underflow" warnings on the subsequent uses of the same loaddata. Before commit a0b7091c4de4 ("apparmor: fix race on rawdata dereference") the dedup path used a get_unless_zero-style helper on a single counter, so the existing "if (tmp)" guard was meaningful. The split-refcount refactor introduced aa_get_profile_loaddata(), which has plain kref_get() semantics, and the guard quietly became a no-op. Introduce aa_get_profile_loaddata_not0(), matching the existing _not0 convention used by aa_get_profile_not0(), and use it for the rawdata_list dedup lookup so dying entries are skipped. Reproduced on x86_64 with v7.1-rc5 in QEMU+KVM running Ubuntu 24.04 + stress-ng 0.17.06: stress-ng --apparmor 1 --klog-check --timeout 60s Without this patch the three refcount_t warnings fire within a few seconds. With it the same 60 s run is clean. Coverage is a smoke-test only; a longer soak with CONFIG_KASAN, CONFIG_KCSAN and CONFIG_PROVE_LOCKING would be welcome from anyone with the cycles. Fixes: a0b7091c4de4 ("apparmor: fix race on rawdata dereference") Reported-by: Colin Ian King Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221513 Cc: stable@vger.kernel.org Signed-off-by: Ruslan Valiyev Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix race between freeing data and fs accessing it

2026-03-09T23:05:44+00:00

AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can aand does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction. Fixes: c961ee5f21b20 ("apparmor: convert from securityfs to apparmorfs for policy ns files") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Signed-off-by: John Johansen

apparmor: fix race on rawdata dereference

2026-03-09T23:05:44+00:00

There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put. Fixes: 5d5182cae401 ("apparmor: move to per loaddata files, instead of replicating in profiles") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Tested-by: Salvatore Bonaccorso Signed-off-by: John Johansen

Merge tag 'apparmor-pr-2022-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

2022-12-14T21:42:09+00:00

Pull apparmor updates from John Johansen: "Features: - switch to zstd compression for profile raw data Cleanups: - simplify obtaining the newest label on a cred - remove useless static inline functions - compute permission conversion on policy unpack - refactor code to share common permissins - refactor unpack to group policy backwards compatiblity code - add __init annotation to aa_{setup/teardown}_dfa_engine() Bug Fixes: - fix a memleak in - multi_transaction_new() - free_ruleset() - unpack_profile() - alloc_ns() - fix lockdep warning when removing a namespace - fix regression in stacking due to label flags - fix loading of child before parent - fix kernel-doc comments that differ from fns - fix spelling errors in comments - store return value of unpack_perms_table() to signed variable" * tag 'apparmor-pr-2022-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: (64 commits) apparmor: Fix uninitialized symbol 'array_size' in policy_unpack_test.c apparmor: Add __init annotation to aa_{setup/teardown}_dfa_engine() apparmor: Fix memleak in alloc_ns() apparmor: Fix memleak issue in unpack_profile() apparmor: fix a memleak in free_ruleset() apparmor: Fix spelling of function name in comment block apparmor: Use pointer to struct aa_label for lbs_cred AppArmor: Fix kernel-doc LSM: Fix kernel-doc AppArmor: Fix kernel-doc apparmor: Fix loading of child before parent apparmor: refactor code that alloc null profiles apparmor: fix obsoleted comments for aa_getprocattr() and audit_resource() apparmor: remove useless static inline functions apparmor: Fix unpack_profile() warn: passing zero to 'ERR_PTR' apparmor: fix uninitialize table variable in error in unpack_trans_table apparmor: store return value of unpack_perms_table() to signed variable apparmor: Fix kunit test for out of bounds array apparmor: Fix decompression of rawdata for read back to userspace apparmor: Fix undefined references to zstd_ symbols ...

apparmor: test: make static symbols visible during kunit testing

2022-12-12T21:13:48+00:00

Use macros, VISIBLE_IF_KUNIT and EXPORT_SYMBOL_IF_KUNIT, to allow static symbols to be conditionally set to be visible during apparmor_policy_unpack_test, which removes the need to include the testing file in the implementation file. Change the namespace of the symbols that are now conditionally visible (by adding the prefix aa_) to avoid confusion with symbols of the same name. Allow the test to be built as a module and namespace the module name from policy_unpack_test to apparmor_policy_unpack_test to improve clarity of the module name. Provide an example of how static symbols can be dealt with in testing. Signed-off-by: Rae Moar Reviewed-by: David Gow Acked-by: John Johansen Signed-off-by: Shuah Khan

apparmor: add user mode flag

2022-10-03T21:49:03+00:00

Allow the profile to contain a user mode prompt flag. This works similar to complain mode but will try to send messages to a userspace daemon. If the daemon is not present or timesout regular informent will occur. Signed-off-by: John Johansen

apparmor: isolate policy backwards compatibility to its own file

2022-10-03T21:49:03+00:00

The details of mapping old policy into newer policy formats clutters up the unpack code and makes it possible to accidentally use old mappings in code, so isolate the mapping code into its own file. This will become more important when the dfa remapping code lands, as it will greatly expand the compat code base. Signed-off-by: John Johansen

apparmor: allow label to carry debug flags

2022-07-19T09:55:45+00:00

Allow labels to have debug flags that can be used to trigger debug output only from profiles/labels that are marked. This can help reduce debug output by allowing debug to be target to a specific confinement condition. Signed-off-by: John Johansen

Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

2019-12-03T20:51:35+00:00

Pull apparmor updates from John Johansen: "Features: - increase left match history buffer size to provide improved conflict resolution in overlapping execution rules. - switch buffer allocation to use a memory pool and GFP_KERNEL where possible. - add compression of policy blobs to reduce memory usage. Cleanups: - fix spelling mistake "immutible" -> "immutable" Bug fixes: - fix unsigned len comparison in update_for_len macro - fix sparse warning for type-casting of current->real_cred" * tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: apparmor: make it so work buffers can be allocated from atomic context apparmor: reduce rcu_read_lock scope for aa_file_perm mediation apparmor: fix wrong buffer allocation in aa_new_mount apparmor: fix unsigned len comparison with less than zero apparmor: increase left match history buffer size apparmor: Switch to GFP_KERNEL where possible apparmor: Use a memory pool instead per-CPU caches apparmor: Force type-casting of current->real_cred apparmor: fix spelling mistake "immutible" -> "immutable" apparmor: fix blob compression when ns is forced on a policy load apparmor: fix missing ZLIB defines apparmor: fix blob compression build failure on ppc apparmor: Initial implementation of raw policy blob compression

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441

2019-06-05T15:37:17+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 315 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Armijn Hemel Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de Signed-off-by: Greg Kroah-Hartman