======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.3.5945/31192 is trying to acquire lock:
ffffffff90b51b68 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217

but task is already holding lock:
ffff88802979a860 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:91 [inline]
ffff88802979a860 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x69/0x80 fs/pipe.c:88

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (&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+0x237/0x370 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

-> #5 (sb_writers#5){.+.+}-{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

-> #4 (&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

-> #3 (&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
       fill_read_buffer fs/configfs/file.c:66 [inline]
       configfs_read_iter+0x346/0x6f0 fs/configfs/file.c:88
       __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+0xcc/0x120 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

-> #2 (&buffer->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
       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+0xcc/0x120 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

-> #1 (&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+0xcc/0x120 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

-> #0 (cb_lock){++++}-{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
       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

other info that might help us debug this:

Chain exists of:
  cb_lock --> sb_writers#5 --> &pipe->mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pipe->mutex);
                               lock(sb_writers#5);
                               lock(&pipe->mutex);
  rlock(cb_lock);

 *** DEADLOCK ***

1 lock held by syz.3.5945/31192:
 #0: ffff88802979a860 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:91 [inline]
 #0: ffff88802979a860 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x69/0x80 fs/pipe.c:88

stack backtrace:
CPU: 0 UID: 0 PID: 31192 Comm: syz.3.5945 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
 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
RIP: 0033:0x7f45f8d9e019
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:00007f45f9d09028 EFLAGS: 00000246 ORIG_RAX: 0000000000000113
RAX: ffffffffffffffda RBX: 00007f45f9026090 RCX: 00007f45f8d9e019
RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f45f8e3500c R08: 000000000004ffe2 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f45f9026128 R14: 00007f45f9026090 R15: 00007ffeed2b6c08
 </TASK>
netlink: 56 bytes leftover after parsing attributes in process `syz.3.5945'.