On 7/30/25 23:46, Borah, Chaitanya Kumar wrote:
On 7/30/2025 4:24 PM, John Johansen wrote:
After bisecting the tree, the following patch [4] seems to be the first "bad"
commit
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commit 88fec3526e84123997ecebd6bb6778eb4ce779b7
Author: John Johansen john.johan...@canonical.com
Date: Thu Jun 19 22:11:52 2025 -0700
apparmor: make sure unix socket labeling is correctly updated.
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We also verified that if we revert the patch the issue is not seen.
Could you please check why the patch causes this regression and provide a fix
if necessary?
yep thanks, fix made. That patch accidentally removed the spinlock
initialization from
apparmor_file_alloc_security() while testing spin lock changes to the very
similar
apparmor_sk_alloc_security(), and it wasn't caught 🙁
anyways fix is being pushed
Thank you John for your response. Kindly share the patch whenever it is
available. So that we can verify the fix.
in apparmor-next it is
43584e993293 apparmor: fix Regression on linux-next (next-20250721)
but also included below
From 43584e993293326cfc508e664fe81f56a65f6240 Mon Sep 17 00:00:00 2001
From: John Johansen <john.johan...@canonical.com>
Date: Wed, 30 Jul 2025 03:47:07 -0700
Subject: [PATCH] apparmor: fix Regression on linux-next (next-20250721)
sk lock initialization was incorrectly removed, from
apparmor_file_alloc_security() while testing changes to changes to
apparmor_sk_alloc_security()
resulting in the following regression.
[ 48.056654] INFO: trying to register non-static key.
[ 48.057480] The code is fine but needs lockdep annotation, or maybe
[ 48.058416] you didn't initialize this object before use?
[ 48.059209] turning off the locking correctness validator.
[ 48.060040] CPU: 0 UID: 0 PID: 648 Comm: chronyd Not tainted
6.16.0-rc7-test-next-20250721-11410-g1ee809985e11-dirty #577 NONE
[ 48.060049] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
1.16.3-debian-1.16.3-2 04/01/2014
[ 48.060055] Call Trace:
[ 48.060059] <TASK>
[ 48.060063] dump_stack_lvl (lib/dump_stack.c:122)
[ 48.060075] register_lock_class (kernel/locking/lockdep.c:988
kernel/locking/lockdep.c:1302)
[ 48.060084] ? path_name (security/apparmor/file.c:159)
[ 48.060093] __lock_acquire (kernel/locking/lockdep.c:5116)
[ 48.060103] lock_acquire (kernel/locking/lockdep.c:473 (discriminator 4)
kernel/locking/lockdep.c:5873 (discriminator 4) kernel/locking/lockdep.c:5828
(discriminator 4))
[ 48.060109] ? update_file_ctx (security/apparmor/file.c:464)
[ 48.060115] ? __pfx_profile_path_perm (security/apparmor/file.c:247)
[ 48.060121] _raw_spin_lock (include/linux/spinlock_api_smp.h:134
kernel/locking/spinlock.c:154)
[ 48.060130] ? update_file_ctx (security/apparmor/file.c:464)
[ 48.060134] update_file_ctx (security/apparmor/file.c:464)
[ 48.060140] aa_file_perm (security/apparmor/file.c:532 (discriminator 1)
security/apparmor/file.c:642 (discriminator 1))
[ 48.060147] ? __pfx_aa_file_perm (security/apparmor/file.c:607)
[ 48.060152] ? do_mmap (mm/mmap.c:558)
[ 48.060160] ? __pfx_userfaultfd_unmap_complete (fs/userfaultfd.c:841)
[ 48.060170] ? __lock_acquire (kernel/locking/lockdep.c:4677 (discriminator
1) kernel/locking/lockdep.c:5194 (discriminator 1))
[ 48.060176] ? common_file_perm (security/apparmor/lsm.c:535 (discriminator
1))
[ 48.060185] security_mmap_file (security/security.c:3012 (discriminator 2))
[ 48.060192] vm_mmap_pgoff (mm/util.c:574 (discriminator 1))
[ 48.060200] ? find_held_lock (kernel/locking/lockdep.c:5353 (discriminator
1))
[ 48.060206] ? __pfx_vm_mmap_pgoff (mm/util.c:568)
[ 48.060212] ? lock_release (kernel/locking/lockdep.c:5539
kernel/locking/lockdep.c:5892 kernel/locking/lockdep.c:5878)
[ 48.060219] ? __fget_files (arch/x86/include/asm/preempt.h:85 (discriminator
13) include/linux/rcupdate.h:100 (discriminator 13)
include/linux/rcupdate.h:873 (discriminator 13) fs/file.c:1072 (discriminator
13))
[ 48.060229] ksys_mmap_pgoff (mm/mmap.c:604)
[ 48.060239] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1)
arch/x86/entry/syscall_64.c:94 (discriminator 1))
[ 48.060248] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 48.060254] RIP: 0033:0x7fb6920e30a2
[ 48.060265] Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48
89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff
77 5e 5b 5d c3 0f 1f 00 c7 05 e6 41 01 00 16 00
All code
========
0: 08 00 or %al,(%rax)
2: 04 00 add $0x0,%al
4: 00 eb add %ch,%bl
6: e2 90 loop 0xffffffffffffff98
8: 41 f7 c1 ff 0f 00 00 test $0xfff,%r9d
f: 75 27 jne 0x38
11: 55 push %rbp
12: 89 cd mov %ecx,%ebp
14: 53 push %rbx
15: 48 89 fb mov %rdi,%rbx
18: 48 85 ff test %rdi,%rdi
1b: 74 33 je 0x50
1d: 41 89 ea mov %ebp,%r10d
20: 48 89 df mov %rbx,%rdi
23: b8 09 00 00 00 mov $0x9,%eax
28: 0f 05 syscall
2a:* 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax <--
trapping instruction
30: 77 5e ja 0x90
32: 5b pop %rbx
33: 5d pop %rbp
34: c3 ret
35: 0f 1f 00 nopl (%rax)
38: c7 .byte 0xc7
39: 05 e6 41 01 00 add $0x141e6,%eax
3e: 16 (bad)
...
Code starting with the faulting instruction
===========================================
0: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
6: 77 5e ja 0x66
8: 5b pop %rbx
9: 5d pop %rbp
a: c3 ret
b: 0f 1f 00 nopl (%rax)
e: c7 .byte 0xc7
f: 05 e6 41 01 00 add $0x141e6,%eax
14: 16 (bad)
...
[ 48.060270] RSP: 002b:00007ffd2c0d3528 EFLAGS: 00000206 ORIG_RAX:
0000000000000009
[ 48.060279] RAX: ffffffffffffffda RBX: 00007fb691fc8000 RCX: 00007fb6920e30a2
[ 48.060283] RDX: 0000000000000005 RSI: 000000000007d000 RDI: 00007fb691fc8000
[ 48.060287] RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000011000
[ 48.060290] R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffd2c0d3578
[ 48.060293] R13: 00007fb6920b6160 R14: 00007ffd2c0d39f0 R15: 00000fffa581a6a8
Fixes: 88fec3526e84 ("apparmor: make sure unix socket labeling is correctly
updated.")
Signed-off-by: John Johansen <john.johan...@canonical.com>
---
security/apparmor/lsm.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index e4b2944431e4..f385913e7d0e 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -505,6 +505,7 @@ static int apparmor_file_alloc_security(struct file *file)
struct aa_file_ctx *ctx = file_ctx(file);
struct aa_label *label = begin_current_label_crit_section();
+ spin_lock_init(&ctx->lock);
rcu_assign_pointer(ctx->label, aa_get_label(label));
end_current_label_crit_section(label);
return 0;
--
2.43.0
