Author: John Johansen <john.johansen@canonical.com>
Date: Fri Oct 17 01:53:00 2025 -0700
apparmor: fix differential encoding verification
commit 39440b137546a3aa383cfdabc605fb73811b6093 upstream.
Differential encoding allows loops to be created if it is abused. To
prevent this the unpack should verify that a diff-encode chain
terminates.
Unfortunately the differential encode verification had two bugs.
1. it conflated states that had gone through check and already been
marked, with states that were currently being checked and marked.
This means that loops in the current chain being verified are treated
as a chain that has already been verified.
2. the order bailout on already checked states compared current chain
check iterators j,k instead of using the outer loop iterator i.
Meaning a step backwards in states in the current chain verification
was being mistaken for moving to an already verified state.
Move to a double mark scheme where already verified states get a
different mark, than the current chain being kept. This enables us
to also drop the backwards verification check that was the cause of
the second error as any already verified state is already marked.
Fixes: 031dcc8f4e84 ("apparmor: dfa add support for state differential encoding")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: John Johansen <john.johansen@canonical.com>
Date: Wed Sep 10 06:22:17 2025 -0700
apparmor: Fix double free of ns_name in aa_replace_profiles()
commit 5df0c44e8f5f619d3beb871207aded7c78414502 upstream.
if ns_name is NULL after
1071 error = aa_unpack(udata, &lh, &ns_name);
and if ent->ns_name contains an ns_name in
1089 } else if (ent->ns_name) {
then ns_name is assigned the ent->ns_name
1095 ns_name = ent->ns_name;
however ent->ns_name is freed at
1262 aa_load_ent_free(ent);
and then again when freeing ns_name at
1270 kfree(ns_name);
Fix this by NULLing out ent->ns_name after it is transferred to ns_name
Fixes: 145a0ef21c8e9 ("apparmor: fix blob compression when ns is forced on a policy load
")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Date: Tue Jan 20 15:24:04 2026 +0100
apparmor: fix memory leak in verify_header
commit e38c55d9f834e5b848bfed0f5c586aaf45acb825 upstream.
The function sets `*ns = NULL` on every call, leaking the namespace
string allocated in previous iterations when multiple profiles are
unpacked. This also breaks namespace consistency checking since *ns
is always NULL when the comparison is made.
Remove the incorrect assignment.
The caller (aa_unpack) initializes *ns to NULL once before the loop,
which is sufficient.
Fixes: dd51c8485763 ("apparmor: provide base for multiple profiles to be replaced at once")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Date: Thu Jan 29 16:51:11 2026 +0100
apparmor: fix missing bounds check on DEFAULT table in verify_dfa()
commit d352873bbefa7eb39995239d0b44ccdf8aaa79a4 upstream.
The verify_dfa() function only checks DEFAULT_TABLE bounds when the state
is not differentially encoded.
When the verification loop traverses the differential encoding chain,
it reads k = DEFAULT_TABLE[j] and uses k as an array index without
validation. A malformed DFA with DEFAULT_TABLE[j] >= state_count,
therefore, causes both out-of-bounds reads and writes.
[ 57.179855] ==================================================================
[ 57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660
[ 57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993
[ 57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)
[ 57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 57.181563] Call Trace:
[ 57.181572] <TASK>
[ 57.181577] dump_stack_lvl+0x5e/0x80
[ 57.181596] print_report+0xc8/0x270
[ 57.181605] ? verify_dfa+0x59a/0x660
[ 57.181608] kasan_report+0x118/0x150
[ 57.181620] ? verify_dfa+0x59a/0x660
[ 57.181623] verify_dfa+0x59a/0x660
[ 57.181627] aa_dfa_unpack+0x1610/0x1740
[ 57.181629] ? __kmalloc_cache_noprof+0x1d0/0x470
[ 57.181640] unpack_pdb+0x86d/0x46b0
[ 57.181647] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181653] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181656] ? aa_unpack_nameX+0x1a8/0x300
[ 57.181659] aa_unpack+0x20b0/0x4c30
[ 57.181662] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181664] ? stack_depot_save_flags+0x33/0x700
[ 57.181681] ? kasan_save_track+0x4f/0x80
[ 57.181683] ? kasan_save_track+0x3e/0x80
[ 57.181686] ? __kasan_kmalloc+0x93/0xb0
[ 57.181688] ? __kvmalloc_node_noprof+0x44a/0x780
[ 57.181693] ? aa_simple_write_to_buffer+0x54/0x130
[ 57.181697] ? policy_update+0x154/0x330
[ 57.181704] aa_replace_profiles+0x15a/0x1dd0
[ 57.181707] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181710] ? __kvmalloc_node_noprof+0x44a/0x780
[ 57.181712] ? aa_loaddata_alloc+0x77/0x140
[ 57.181715] ? srso_alias_return_thunk+0x5/0xfbef5
[ 57.181717] ? _copy_from_user+0x2a/0x70
[ 57.181730] policy_update+0x17a/0x330
[ 57.181733] profile_replace+0x153/0x1a0
[ 57.181735] ? rw_verify_area+0x93/0x2d0
[ 57.181740] vfs_write+0x235/0xab0
[ 57.181745] ksys_write+0xb0/0x170
[ 57.181748] do_syscall_64+0x8e/0x660
[ 57.181762] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 57.181765] RIP: 0033:0x7f6192792eb2
Remove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE
entries unconditionally.
Fixes: 031dcc8f4e84 ("apparmor: dfa add support for state differential encoding")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: John Johansen <john.johansen@canonical.com>
Date: Sun Mar 1 16:10:51 2026 -0800
apparmor: fix race between freeing data and fs accessing it
commit 8e135b8aee5a06c52a4347a5a6d51223c6f36ba3 upstream.
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 <qsa@qualys.com>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Maxime Bélair <maxime.belair@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: John Johansen <john.johansen@canonical.com>
Date: Tue Feb 24 10:20:02 2026 -0800
apparmor: fix race on rawdata dereference
commit a0b7091c4de45a7325c8780e6934a894f92ac86b upstream.
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 <qsa@qualys.com>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Maxime Bélair <maxime.belair@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Date: Thu Jan 29 17:08:25 2026 +0100
apparmor: fix side-effect bug in match_char() macro usage
commit 8756b68edae37ff546c02091989a4ceab3f20abd upstream.
The match_char() macro evaluates its character parameter multiple
times when traversing differential encoding chains. When invoked
with *str++, the string pointer advances on each iteration of the
inner do-while loop, causing the DFA to check different characters
at each iteration and therefore skip input characters.
This results in out-of-bounds reads when the pointer advances past
the input buffer boundary.
[ 94.984676] ==================================================================
[ 94.985301] BUG: KASAN: slab-out-of-bounds in aa_dfa_match+0x5ae/0x760
[ 94.985655] Read of size 1 at addr ffff888100342000 by task file/976
[ 94.986319] CPU: 7 UID: 1000 PID: 976 Comm: file Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)
[ 94.986322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 94.986329] Call Trace:
[ 94.986341] <TASK>
[ 94.986347] dump_stack_lvl+0x5e/0x80
[ 94.986374] print_report+0xc8/0x270
[ 94.986384] ? aa_dfa_match+0x5ae/0x760
[ 94.986388] kasan_report+0x118/0x150
[ 94.986401] ? aa_dfa_match+0x5ae/0x760
[ 94.986405] aa_dfa_match+0x5ae/0x760
[ 94.986408] __aa_path_perm+0x131/0x400
[ 94.986418] aa_path_perm+0x219/0x2f0
[ 94.986424] apparmor_file_open+0x345/0x570
[ 94.986431] security_file_open+0x5c/0x140
[ 94.986442] do_dentry_open+0x2f6/0x1120
[ 94.986450] vfs_open+0x38/0x2b0
[ 94.986453] ? may_open+0x1e2/0x2b0
[ 94.986466] path_openat+0x231b/0x2b30
[ 94.986469] ? __x64_sys_openat+0xf8/0x130
[ 94.986477] do_file_open+0x19d/0x360
[ 94.986487] do_sys_openat2+0x98/0x100
[ 94.986491] __x64_sys_openat+0xf8/0x130
[ 94.986499] do_syscall_64+0x8e/0x660
[ 94.986515] ? count_memcg_events+0x15f/0x3c0
[ 94.986526] ? srso_alias_return_thunk+0x5/0xfbef5
[ 94.986540] ? handle_mm_fault+0x1639/0x1ef0
[ 94.986551] ? vma_start_read+0xf0/0x320
[ 94.986558] ? srso_alias_return_thunk+0x5/0xfbef5
[ 94.986561] ? srso_alias_return_thunk+0x5/0xfbef5
[ 94.986563] ? fpregs_assert_state_consistent+0x50/0xe0
[ 94.986572] ? srso_alias_return_thunk+0x5/0xfbef5
[ 94.986574] ? arch_exit_to_user_mode_prepare+0x9/0xb0
[ 94.986587] ? srso_alias_return_thunk+0x5/0xfbef5
[ 94.986588] ? irqentry_exit+0x3c/0x590
[ 94.986595] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 94.986597] RIP: 0033:0x7fda4a79c3ea
Fix by extracting the character value before invoking match_char,
ensuring single evaluation per outer loop.
Fixes: 074c1cd798cb ("apparmor: dfa move character match into a macro")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: John Johansen <john.johansen@canonical.com>
Date: Fri Nov 7 08:36:04 2025 -0800
apparmor: fix unprivileged local user can do privileged policy management
commit 6601e13e82841879406bf9f369032656f441a425 upstream.
An unprivileged local user can load, replace, and remove profiles by
opening the apparmorfs interfaces, via a confused deputy attack, by
passing the opened fd to a privileged process, and getting the
privileged process to write to the interface.
This does require a privileged target that can be manipulated to do
the write for the unprivileged process, but once such access is
achieved full policy management is possible and all the possible
implications that implies: removing confinement, DoS of system or
target applications by denying all execution, by-passing the
unprivileged user namespace restriction, to exploiting kernel bugs for
a local privilege escalation.
The policy management interface can not have its permissions simply
changed from 0666 to 0600 because non-root processes need to be able
to load policy to different policy namespaces.
Instead ensure the task writing the interface has privileges that
are a subset of the task that opened the interface. This is already
done via policy for confined processes, but unconfined can delegate
access to the opened fd, by-passing the usual policy check.
Fixes: b7fd2c0340eac ("apparmor: add per policy ns .load, .replace, .remove interface files")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: John Johansen <john.johansen@canonical.com>
Date: Tue Mar 3 11:08:02 2026 -0800
apparmor: fix: limit the number of levels of policy namespaces
commit 306039414932c80f8420695a24d4fe10c84ccfb2 upstream.
Currently the number of policy namespaces is not bounded relying on
the user namespace limit. However policy namespaces aren't strictly
tied to user namespaces and it is possible to create them and nest
them arbitrarily deep which can be used to exhaust system resource.
Hard cap policy namespaces to the same depth as user namespaces.
Fixes: c88d4c7b049e8 ("AppArmor: core policy routines")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Reviewed-by: Ryan Lee <ryan.lee@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Date: Tue Jan 13 09:09:43 2026 +0100
apparmor: replace recursive profile removal with iterative approach
commit ab09264660f9de5d05d1ef4e225aa447c63a8747 upstream.
The profile removal code uses recursion when removing nested profiles,
which can lead to kernel stack exhaustion and system crashes.
Reproducer:
$ pf='a'; for ((i=0; i<1024; i++)); do
echo -e "profile $pf { \n }" | apparmor_parser -K -a;
pf="$pf//x";
done
$ echo -n a > /sys/kernel/security/apparmor/.remove
Replace the recursive __aa_profile_list_release() approach with an
iterative approach in __remove_profile(). The function repeatedly
finds and removes leaf profiles until the entire subtree is removed,
maintaining the same removal semantic without recursion.
Fixes: c88d4c7b049e ("AppArmor: core policy routines")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Date: Thu Jan 15 15:30:50 2026 +0100
apparmor: validate DFA start states are in bounds in unpack_pdb
commit 9063d7e2615f4a7ab321de6b520e23d370e58816 upstream.
Start states are read from untrusted data and used as indexes into the
DFA state tables. The aa_dfa_next() function call in unpack_pdb() will
access dfa->tables[YYTD_ID_BASE][start], and if the start state exceeds
the number of states in the DFA, this results in an out-of-bound read.
==================================================================
BUG: KASAN: slab-out-of-bounds in aa_dfa_next+0x2a1/0x360
Read of size 4 at addr ffff88811956fb90 by task su/1097
...
Reject policies with out-of-bounds start states during unpacking
to prevent the issue.
Fixes: ad5ff3db53c6 ("AppArmor: Add ability to load extended policy")
Reported-by: Qualys Security Advisory <qsa@qualys.com>
Tested-by: Salvatore Bonaccorso <carnil@debian.org>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Reviewed-by: Cengiz Can <cengiz.can@canonical.com>
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri Mar 13 17:26:05 2026 +0100
Linux 6.19.8
Link: https://lore.kernel.org/r/20260312200321.671986598@linuxfoundation.org
Tested-by: Brett A C Sheffield <bacs@librecast.net>
Tested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Ronald Warsow <rwarsow@gmx.de>
Tested-by: Ron Economos <re@w6rz.net>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Paul Moses <p@1g4.org>
Date: Mon Feb 23 15:05:44 2026 +0000
net/sched: act_gate: snapshot parameters with RCU on replace
commit 62413a9c3cb183afb9bb6e94dd68caf4e4145f4c upstream.
The gate action can be replaced while the hrtimer callback or dump path is
walking the schedule list.
Convert the parameters to an RCU-protected snapshot and swap updates under
tcf_lock, freeing the previous snapshot via call_rcu(). When REPLACE omits
the entry list, preserve the existing schedule so the effective state is
unchanged.
Fixes: a51c328df310 ("net: qos: introduce a gate control flow action")
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moses <p@1g4.org>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260223150512.2251594-2-p@1g4.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Author: Victor Nogueira <victor@mojatatu.com>
Date: Wed Feb 25 10:43:48 2026 -0300
net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks
commit 11cb63b0d1a0685e0831ae3c77223e002ef18189 upstream.
As Paolo said earlier [1]:
"Since the blamed commit below, classify can return TC_ACT_CONSUMED while
the current skb being held by the defragmentation engine. As reported by
GangMin Kim, if such packet is that may cause a UaF when the defrag engine
later on tries to tuch again such packet."
act_ct was never meant to be used in the egress path, however some users
are attaching it to egress today [2]. Attempting to reach a middle
ground, we noticed that, while most qdiscs are not handling
TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we
address the issue by only allowing act_ct to bind to clsact/ingress
qdiscs and shared blocks. That way it's still possible to attach act_ct to
egress (albeit only with clsact).
[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/
[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/
Reported-by: GangMin Kim <km.kim1503@gmail.com>
Fixes: 3f14b377d01d ("net/sched: act_ct: fix skb leak and crash on ooo frags")
CC: stable@vger.kernel.org
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260225134349.1287037-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>