Hello,
syzbot found the following issue on:
HEAD commit: f5098b6bae76 Linux 7.2-rc5
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=137026b9580000
kernel config:
https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link:
https://syzkaller.appspot.com/bug?extid=d2085ac2d653b9e383e2
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/2113dcf433f6/disk-f5098b6b.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/413e673b7de4/vmlinux-f5098b6b.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/fc40c1b83e80/bzImage-f5098b6b.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+d2085a...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.3.4908/17817 is trying to acquire lock:
ffff88807ab9cc80 (&buffer->mutex){+.+.}-{4:4}, at: configfs_read_iter+0x79/0x6f0 fs/configfs/file.c:86
but task is already holding lock:
ffff8880741349a8 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #6 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
security_file_post_open+0xc4/0x210 security/security.c:2755
do_open fs/namei.c:4702 [inline]
path_openat+0x985/0x4280 fs/namei.c:4863
do_file_open_root+0x2f6/0x5a0 fs/namei.c:4916
file_open_root+0x1c6/0x3f0 fs/open.c:1355
kernel_read_file_from_path_initns+0x189/0x260 fs/kernel_read_file.c:163
fw_get_filesystem_firmware drivers/base/firmware_loader/main.c:549 [inline]
_request_firmware+0x733/0x13c0 drivers/base/firmware_loader/main.c:873
request_firmware+0x35/0x50 drivers/base/firmware_loader/main.c:948
reg_reload_regdb+0x85/0x460 net/wireless/reg.c:1067
genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
__sys_sendmsg+0x160/0x210 net/socket.c:2770
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #5 (cb_lock){++++}-{4:4}:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
down_read+0x99/0x4c0 kernel/locking/rwsem.c:1574
genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
sock_sendmsg+0x394/0x410 net/socket.c:813
splice_to_socket+0xb3c/0x11a0 fs/splice.c:884
do_splice_from fs/splice.c:936 [inline]
do_splice+0x109c/0x1f90 fs/splice.c:1349
__do_splice+0x33b/0x370 fs/splice.c:1431
__do_sys_splice fs/splice.c:1634 [inline]
__se_sys_splice fs/splice.c:1616 [inline]
__x64_sys_splice+0x187/0x250 fs/splice.c:1616
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #4 (&pipe->mutex){+.+.}-{4:4}:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
pipe_lock fs/pipe.c:91 [inline]
pipe_lock+0x69/0x80 fs/pipe.c:88
iter_file_splice_write+0x1fd/0x10b0 fs/splice.c:682
do_splice_from fs/splice.c:936 [inline]
do_splice+0x109c/0x1f90 fs/splice.c:1349
__do_splice+0x33b/0x370 fs/splice.c:1431
__do_sys_splice fs/splice.c:1634 [inline]
__se_sys_splice fs/splice.c:1616 [inline]
__x64_sys_splice+0x187/0x250 fs/splice.c:1616
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #3 (sb_writers#6){.+.+}-{0:0}:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
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 include/linux/fs/super.h:125 [inline]
mnt_want_write+0x6f/0x410 fs/namespace.c:494
open_last_lookups fs/namei.c:4597 [inline]
path_openat+0xad9/0x4280 fs/namei.c:4860
do_file_open+0x20e/0x430 fs/namei.c:4892
file_open_name+0x1c3/0x3e0 fs/open.c:1326
filp_open+0x2e/0x50 fs/open.c:1343
fsg_lun_open+0x6b/0x7b0 drivers/usb/gadget/function/storage_common.c:194
fsg_store_file+0x1e7/0x450 drivers/usb/gadget/function/storage_common.c:455
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (&common->filesem){+.+.}-{4:4}:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1631
fsg_store_file+0x193/0x450 drivers/usb/gadget/function/storage_common.c:452
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&p->frag_sem){.+.+}-{4:4}:
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
down_read+0x99/0x4c0 kernel/locking/rwsem.c:1574
flush_write_buffer fs/configfs/file.c:205 [inline]
configfs_write_iter+0x218/0x4e0 fs/configfs/file.c:229
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&buffer->mutex){+.+.}-{4:4}:
check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
configfs_read_iter+0x79/0x6f0 fs/configfs/file.c:86
__kernel_read+0x397/0xad0 fs/read_write.c:532
integrity_kernel_read+0x7e/0xb0 security/integrity/iint.c:28
ima_calc_file_hash_tfm+0x25e/0x350 security/integrity/ima/ima_crypto.c:222
ima_calc_file_hash+0x1e3/0x380 security/integrity/ima/ima_crypto.c:280
ima_collect_measurement+0x94f/0xb30 security/integrity/ima/ima_api.c:300
process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:425
ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
security_file_post_open+0xc4/0x210 security/security.c:2755
do_open fs/namei.c:4702 [inline]
path_openat+0x985/0x4280 fs/namei.c:4863
do_file_open+0x20e/0x430 fs/namei.c:4892
do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&buffer->mutex --> cb_lock --> &ima_iint_mutex_key[depth]
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ima_iint_mutex_key[depth]);
lock(cb_lock);
lock(&ima_iint_mutex_key[depth]);
lock(&buffer->mutex);
*** DEADLOCK ***
1 lock held by syz.3.4908/17817:
#0: ffff8880741349a8 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
stack backtrace:
CPU: 0 UID: 0 PID: 17817 Comm: syz.3.4908 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043
check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175
check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3165
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
configfs_read_iter+0x79/0x6f0 fs/configfs/file.c:86
__kernel_read+0x397/0xad0 fs/read_write.c:532
integrity_kernel_read+0x7e/0xb0 security/integrity/iint.c:28
ima_calc_file_hash_tfm+0x25e/0x350 security/integrity/ima/ima_crypto.c:222
ima_calc_file_hash+0x1e3/0x380 security/integrity/ima/ima_crypto.c:280
ima_collect_measurement+0x94f/0xb30 security/integrity/ima/ima_api.c:300
process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:425
ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
security_file_post_open+0xc4/0x210 security/security.c:2755
do_open fs/namei.c:4702 [inline]
path_openat+0x985/0x4280 fs/namei.c:4863
do_file_open+0x20e/0x430 fs/namei.c:4892
do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3adaf9de99
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:00007f3adbf33028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3adb225fa0 RCX: 00007f3adaf9de99
RDX: 0000000000000000 RSI: 0000200000000640 RDI: ffffffffffffff9c
RBP: 00007f3adb033eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3adb226038 R14: 00007f3adb225fa0 R15: 00007ffd05bb3858
</TASK>
syz_tun (unregistering): left allmulticast mode
---
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