mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity
linux-stable/security/apparmor
History
Fedor Pchelkin 0a12db736e apparmor: avoid crash when parsed profile name is empty 
[ Upstream commit 55a8210c9e ]

When processing a packed profile in unpack_profile() described like

 "profile :ns::samba-dcerpcd /usr/lib*/samba/{,samba/}samba-dcerpcd {...}"

a string ":samba-dcerpcd" is unpacked as a fully-qualified name and then
passed to aa_splitn_fqname().

aa_splitn_fqname() treats ":samba-dcerpcd" as only containing a namespace.
Thus it returns NULL for tmpname, meanwhile tmpns is non-NULL. Later
aa_alloc_profile() crashes as the new profile name is NULL now.

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 6 PID: 1657 Comm: apparmor_parser Not tainted 6.7.0-rc2-dirty #16
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
RIP: 0010:strlen+0x1e/0xa0
Call Trace:
 <TASK>
 ? strlen+0x1e/0xa0
 aa_policy_init+0x1bb/0x230
 aa_alloc_profile+0xb1/0x480
 unpack_profile+0x3bc/0x4960
 aa_unpack+0x309/0x15e0
 aa_replace_profiles+0x213/0x33c0
 policy_update+0x261/0x370
 profile_replace+0x20e/0x2a0
 vfs_write+0x2af/0xe00
 ksys_write+0x126/0x250
 do_syscall_64+0x46/0xf0
 entry_SYSCALL_64_after_hwframe+0x6e/0x76
 </TASK>
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x1e/0xa0

It seems such behaviour of aa_splitn_fqname() is expected and checked in
other places where it is called (e.g. aa_remove_profiles). Well, there
is an explicit comment "a ns name without a following profile is allowed"
inside.

AFAICS, nothing can prevent unpacked "name" to be in form like
":samba-dcerpcd" - it is passed from userspace.

Deny the whole profile set replacement in such case and inform user with
EPROTO and an explaining message.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 04dc715e24 ("apparmor: audit policy ns specified in policy load")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
 		2024-01-25 14:52:52 -08:00
..
include apparmor: fix overlapping attachment computation 2022-08-25 11:40:00 +02:00
.gitignore
…
Kconfig
…
Makefile
…
apparmorfs.c apparmor: fix a memleak in multi_transaction_new() 2022-12-31 13:14:21 +01:00
audit.c apparmor: fix quiet_denied for file rules 2022-08-25 11:39:59 +02:00
capability.c
…
crypto.c
…
domain.c apparmor: fix overlapping attachment computation 2022-08-25 11:40:00 +02:00
file.c apparmor: handle idmapped mounts 2021-01-24 14:27:20 +01:00
ipc.c
…
label.c apparmor: fix aa_label_asxprint return check 2022-08-25 11:40:00 +02:00
lib.c
…
lsm.c apparmor: Use pointer to struct aa_label for lbs_cred 2022-12-31 13:14:21 +01:00
match.c
…
mount.c apparmor: fix reference count leak in aa_pivotroot() 2022-08-25 11:40:01 +02:00
net.c
…
nulldfa.in
…
path.c
…
policy.c apparmor: fix lockdep warning when removing a namespace 2022-12-31 13:14:21 +01:00
policy_ns.c apparmor: Fix memleak in alloc_ns() 2022-12-31 13:14:22 +01:00
policy_unpack.c apparmor: avoid crash when parsed profile name is empty 2024-01-25 14:52:52 -08:00
policy_unpack_test.c
…
procattr.c
…
resource.c
…
secid.c
…
stacksplitdfa.in
…
task.c
…