* [syzbot] [fs?] possible deadlock in ima_path_truncate
@ 2026-08-26 4:45 syzbot
0 siblings, 0 replies; only message in thread
From: syzbot @ 2026-08-26 4:45 UTC (permalink / raw)
To: a.hindborg, leitao, linux-fsdevel, linux-kernel, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 818bebeb63dd drm/xe: Don't hand out the flat CCS storage a..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17c6be79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3c35c7e43de75adb
dashboard link: https://syzkaller.appspot.com/bug?extid=ecf337bf2c6f75c1ddd8
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-818bebeb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9adea981957f/vmlinux-818bebeb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6676075cd03e/bzImage-818bebeb.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ecf337bf2c6f75c1ddd8@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.0/5310 is trying to acquire lock:
ffff888043b8ecc0 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_reset_action_flags security/integrity/ima/ima_main.c:708 [inline]
ffff888043b8ecc0 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: ima_path_truncate+0xd3/0x190 security/integrity/ima/ima_main.c:717
but task is already holding lock:
ffff8880347c0460 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #4 (sb_writers#11){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x4d/0x1d0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:494
lookup_open+0x1e6/0x1a40 fs/namei.c:4451
open_last_lookups fs/namei.c:4767 [inline]
path_openat+0x677/0x1d60 fs/namei.c:4997
do_file_open+0x23e/0x4a0 fs/namei.c:5029
file_open_name fs/open.c:1375 [inline]
filp_open+0x16d/0x1d0 fs/open.c:1392
fsg_lun_open+0x6c/0xdf0 drivers/usb/gadget/function/storage_common.c:194
fsg_store_file+0x19e/0x400 drivers/usb/gadget/function/storage_common.c:455
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #3 (&common->filesem){++++}-{4:4}:
down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
fsg_show_file+0x2d/0x140 drivers/usb/gadget/function/storage_common.c:339
fill_read_buffer fs/configfs/file.c:68 [inline]
configfs_read_iter+0x2b7/0x620 fs/configfs/file.c:88
__kernel_read+0x4ca/0x960 fs/read_write.c:532
integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280
ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300
process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425
ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
security_file_post_open+0xb3/0x260 security/security.c:2755
do_open fs/namei.c:4839 [inline]
path_openat+0x1485/0x1d60 fs/namei.c:5000
do_file_open+0x23e/0x4a0 fs/namei.c:5029
do_sys_openat2+0x115/0x200 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1434
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (&p->frag_sem){.+.+}-{4:4}:
down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
fill_read_buffer fs/configfs/file.c:66 [inline]
configfs_read_iter+0x1cc/0x620 fs/configfs/file.c:88
__kernel_read+0x4ca/0x960 fs/read_write.c:532
integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280
ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300
process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425
ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
security_file_post_open+0xb3/0x260 security/security.c:2755
do_open fs/namei.c:4839 [inline]
path_openat+0x1485/0x1d60 fs/namei.c:5000
do_file_open+0x23e/0x4a0 fs/namei.c:5029
do_sys_openat2+0x115/0x200 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1434
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&buffer->mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
configfs_read_iter+0x70/0x620 fs/configfs/file.c:86
__kernel_read+0x4ca/0x960 fs/read_write.c:532
integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280
ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300
process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425
ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
security_file_post_open+0xb3/0x260 security/security.c:2755
do_open fs/namei.c:4839 [inline]
path_openat+0x1485/0x1d60 fs/namei.c:5000
do_file_open+0x23e/0x4a0 fs/namei.c:5029
do_sys_openat2+0x115/0x200 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1434
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3181 [inline]
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
ima_reset_action_flags security/integrity/ima/ima_main.c:708 [inline]
ima_path_truncate+0xd3/0x190 security/integrity/ima/ima_main.c:717
security_path_truncate+0x1d0/0x310 security/security.c:1563
vfs_truncate+0x46b/0x540 fs/open.c:116
ksys_truncate+0xf3/0x1c0 fs/open.c:142
__do_sys_truncate fs/open.c:154 [inline]
__se_sys_truncate fs/open.c:152 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:152
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&ima_iint_mutex_key[depth] --> &common->filesem --> sb_writers#11
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
rlock(sb_writers#11);
lock(&common->filesem);
lock(sb_writers#11);
lock(&ima_iint_mutex_key[depth]);
*** DEADLOCK ***
locks held by syz.0.0/5310: 1, last CPU#0:
#0: ffff8880347c0460 (sb_writers#11){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
stack backtrace:
CPU: 0 UID: 0 PID: 5310 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191
check_prev_add kernel/locking/lockdep.c:3181 [inline]
check_prevs_add kernel/locking/lockdep.c:3300 [inline]
validate_chain kernel/locking/lockdep.c:3924 [inline]
__lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
ima_reset_action_flags security/integrity/ima/ima_main.c:708 [inline]
ima_path_truncate+0xd3/0x190 security/integrity/ima/ima_main.c:717
security_path_truncate+0x1d0/0x310 security/security.c:1563
vfs_truncate+0x46b/0x540 fs/open.c:116
ksys_truncate+0xf3/0x1c0 fs/open.c:142
__do_sys_truncate fs/open.c:154 [inline]
__se_sys_truncate fs/open.c:152 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:152
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92a899e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f92a97d3fe8 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f92a8c26090 RCX: 00007f92a899e0d9
RDX: 0000000000000000 RSI: 0000000000000c88 RDI: 0000200000000100
RBP: 00007f92a8a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92a8c26128 R14: 00007f92a8c26090 R15: 00007ffcdcc3c1d8
</TASK>
---
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2026-08-26 4:45 [syzbot] [fs?] possible deadlock in ima_path_truncate syzbot
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