====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.755/8572 is trying to acquire lock: ffff888070482938 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_write fs/autofs/waitq.c:68 [inline] ffff888070482938 (&sbi->pipe_mutex){+.+.}-{4:4}, at: autofs_notify_daemon+0x509/0xe00 fs/autofs/waitq.c:177 but task is already holding lock: ffff88804d1e8480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&of->mutex){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821 kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:165 seq_read_iter+0x2c1/0x1270 fs/seq_file.c:226 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:290 __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+0x952/0xb30 security/integrity/ima/ima_api.c:300 process_measurement+0xe04/0x2360 security/integrity/ima/ima_main.c:425 ima_file_check+0xc8/0x120 security/integrity/ima/ima_main.c:686 security_file_post_open+0xc4/0x210 security/security.c:2776 do_open fs/namei.c:4853 [inline] path_openat+0x5d0/0x23f0 fs/namei.c:5016 do_file_open+0x20e/0x430 fs/namei.c:5045 do_sys_openat2+0x163/0x1d0 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_compat_sys_openat fs/open.c:1510 [inline] __se_compat_sys_openat fs/open.c:1508 [inline] __ia32_compat_sys_openat+0x12d/0x210 fs/open.c:1508 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #4 (&p->lock){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821 seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:290 __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+0x952/0xb30 security/integrity/ima/ima_api.c:300 process_measurement+0xe04/0x2360 security/integrity/ima/ima_main.c:425 ima_file_check+0xc8/0x120 security/integrity/ima/ima_main.c:686 security_file_post_open+0xc4/0x210 security/security.c:2776 do_open fs/namei.c:4853 [inline] path_openat+0x5d0/0x23f0 fs/namei.c:5016 do_file_open+0x20e/0x430 fs/namei.c:5045 do_sys_openat2+0x163/0x1d0 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1459 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x121/0x770 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821 process_measurement+0x5ab/0x2360 security/integrity/ima/ima_main.c:319 ima_file_check+0xc8/0x120 security/integrity/ima/ima_main.c:686 security_file_post_open+0xc4/0x210 security/security.c:2776 do_open fs/namei.c:4853 [inline] path_openat+0x5d0/0x23f0 fs/namei.c:5016 do_file_open+0x20e/0x430 fs/namei.c:5045 file_open_name+0x1c3/0x3e0 fs/open.c:1400 filp_open+0x2e/0x50 fs/open.c:1417 kernel_read_file_from_path_initns+0xec/0x240 fs/kernel_read_file.c:159 fw_get_filesystem_firmware drivers/base/firmware_loader/main.c:549 [inline] _request_firmware+0x6f1/0x1410 drivers/base/firmware_loader/main.c:873 request_firmware+0x35/0x50 drivers/base/firmware_loader/main.c:948 reg_reload_regdb+0x87/0x540 net/wireless/reg.c:1075 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:2584 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x668/0x950 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x9ac/0x10c0 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0xa99/0xc30 net/socket.c:2715 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2769 __sys_sendmsg+0x160/0x210 net/socket.c:2801 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #2 (cb_lock){++++}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 down_read+0x94/0x4c0 kernel/locking/rwsem.c:1574 genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x668/0x950 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x9ac/0x10c0 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:818 [inline] sock_sendmsg+0x39f/0x420 net/socket.c:841 splice_to_socket+0xbd5/0x1230 fs/splice.c:884 do_splice_from fs/splice.c:936 [inline] do_splice+0x10a2/0x2090 fs/splice.c:1377 __do_splice+0x33b/0x370 fs/splice.c:1459 __do_sys_splice fs/splice.c:1662 [inline] __se_sys_splice fs/splice.c:1644 [inline] __ia32_sys_splice+0x189/0x250 fs/splice.c:1644 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #1 (&pipe->mutex){+.+.}-{4:4}: lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821 anon_pipe_prefill_and_lock+0x16c/0x580 fs/pipe.c:165 anon_pipe_write+0x164/0x1bb0 fs/pipe.c:534 __kernel_write_iter+0x6bb/0x930 fs/read_write.c:621 __kernel_write+0xf6/0x140 fs/read_write.c:641 autofs_write fs/autofs/waitq.c:70 [inline] autofs_notify_daemon+0x51e/0xe00 fs/autofs/waitq.c:177 autofs_wait+0x10f8/0x1b30 fs/autofs/waitq.c:439 autofs_mount_wait+0x132/0x3b0 fs/autofs/root.c:256 autofs_d_automount+0x490/0x950 fs/autofs/root.c:410 follow_automount fs/namei.c:1571 [inline] __traverse_mounts+0x1b9/0x8a0 fs/namei.c:1624 traverse_mounts fs/namei.c:1653 [inline] handle_mounts fs/namei.c:1755 [inline] step_into_slowpath+0xb7e/0xf90 fs/namei.c:2110 step_into fs/namei.c:2158 [inline] walk_component fs/namei.c:2294 [inline] link_path_walk+0xe4a/0x1bd0 fs/namei.c:2662 path_lookupat+0x74/0xc40 fs/namei.c:2818 filename_lookup+0x202/0x590 fs/namei.c:2848 user_path_at+0x3c/0x60 fs/namei.c:3647 do_mount fs/namespace.c:4347 [inline] __do_sys_mount fs/namespace.c:4565 [inline] __se_sys_mount fs/namespace.c:4542 [inline] __ia32_sys_mount+0x1fb/0x310 fs/namespace.c:4542 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #0 (&sbi->pipe_mutex){+.+.}-{4:4}: check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209 check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288 lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821 autofs_write fs/autofs/waitq.c:68 [inline] autofs_notify_daemon+0x509/0xe00 fs/autofs/waitq.c:177 autofs_wait+0x10f8/0x1b30 fs/autofs/waitq.c:439 autofs_mount_wait+0x132/0x3b0 fs/autofs/root.c:256 autofs_d_automount+0x490/0x950 fs/autofs/root.c:410 follow_automount fs/namei.c:1571 [inline] __traverse_mounts+0x1b9/0x8a0 fs/namei.c:1624 traverse_mounts fs/namei.c:1653 [inline] handle_mounts fs/namei.c:1755 [inline] step_into_slowpath+0xb7e/0xf90 fs/namei.c:2110 step_into fs/namei.c:2158 [inline] walk_component fs/namei.c:2294 [inline] lookup_last fs/namei.c:2795 [inline] path_lookupat+0x58b/0xc40 fs/namei.c:2819 filename_lookup+0x202/0x590 fs/namei.c:2848 kern_path+0x37/0x50 fs/namei.c:3042 lookup_bdev+0xd8/0x2a0 block/bdev.c:1268 resume_store+0x1f5/0x480 kernel/power/hibernate.c:1286 kobj_attr_store+0x58/0x80 lib/kobject.c:842 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: &sbi->pipe_mutex --> &p->lock --> &of->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&of->mutex); lock(&p->lock); lock(&of->mutex); lock(&sbi->pipe_mutex); *** DEADLOCK *** locks held by syz.1.755/8572: 4, last CPU#3: #0: ffff888014c44470 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1409 #1: ffff888022e34478 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #2: ffff88804d1e8480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336 #3: ffff88801eb685a8 (kn->active#74){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #3: ffff88801eb685a8 (kn->active#74){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:337 stack backtrace: CPU: 3 UID: 0 PID: 8572 Comm: syz.1.755 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: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2087 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2219 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209 check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288 lock_acquire kernel/locking/lockdep.c:5942 [inline] lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19f/0x1c10 kernel/locking/mutex.c:821 autofs_write fs/autofs/waitq.c:68 [inline] autofs_notify_daemon+0x509/0xe00 fs/autofs/waitq.c:177 autofs_wait+0x10f8/0x1b30 fs/autofs/waitq.c:439 autofs_mount_wait+0x132/0x3b0 fs/autofs/root.c:256 autofs_d_automount+0x490/0x950 fs/autofs/root.c:410 follow_automount fs/namei.c:1571 [inline] __traverse_mounts+0x1b9/0x8a0 fs/namei.c:1624 traverse_mounts fs/namei.c:1653 [inline] handle_mounts fs/namei.c:1755 [inline] step_into_slowpath+0xb7e/0xf90 fs/namei.c:2110 step_into fs/namei.c:2158 [inline] walk_component fs/namei.c:2294 [inline] lookup_last fs/namei.c:2795 [inline] path_lookupat+0x58b/0xc40 fs/namei.c:2819 filename_lookup+0x202/0x590 fs/namei.c:2848 kern_path+0x37/0x50 fs/namei.c:3042 lookup_bdev+0xd8/0x2a0 block/bdev.c:1268 resume_store+0x1f5/0x480 kernel/power/hibernate.c:1286 kobj_attr_store+0x58/0x80 lib/kobject.c:842 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf745efbc Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8 RSP: 002b:00000000f543450c EFLAGS: 00000292 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000080000040 RDX: 0000000000000012 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 PM: Image not found (code -6) ---------------- Code disassembly (best guess): 0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1) 4: e8 0c 89 02 8b call 0x8b028915 9: 5d pop %rbp a: fc cld b: 31 c0 xor %eax,%eax d: c9 leave e: c3 ret f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi 36: 00 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 3e: 58 pop %rax 3f: b8 .byte 0xb8