====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc6-syzkaller-00007-g0b46b049d6ec #0 Not tainted ------------------------------------------------------ syz.4.3544/16863 is trying to acquire lock: ffff888063695b38 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 but task is already holding lock: ffff888024a08868 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:92 [inline] ffff888024a08868 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x64/0x80 fs/pipe.c:89 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&pipe->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 pipe_lock fs/pipe.c:92 [inline] pipe_lock+0x64/0x80 fs/pipe.c:89 iter_file_splice_write+0x1eb/0x10b0 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0x146a/0x1f70 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1639 [inline] __se_sys_splice fs/splice.c:1621 [inline] __x64_sys_splice+0x187/0x250 fs/splice.c:1621 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (sb_writers#6){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1785 [inline] sb_start_write include/linux/fs.h:1921 [inline] mnt_want_write+0x6f/0x450 fs/namespace.c:547 ovl_set_or_remove_acl fs/overlayfs/inode.c:517 [inline] ovl_set_acl+0x637/0x9f0 fs/overlayfs/inode.c:566 set_posix_acl+0x25c/0x320 fs/posix_acl.c:954 vfs_set_acl+0x5a7/0x930 fs/posix_acl.c:1133 do_set_acl+0xd9/0x1a0 fs/posix_acl.c:1278 do_setxattr+0xe7/0x170 fs/xattr.c:633 filename_setxattr+0x16d/0x1d0 fs/xattr.c:665 path_setxattrat+0x1e0/0x290 fs/xattr.c:713 __do_sys_setxattr fs/xattr.c:747 [inline] __se_sys_setxattr fs/xattr.c:743 [inline] __x64_sys_setxattr+0xc6/0x140 fs/xattr.c:743 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 inode_lock_shared include/linux/fs.h:887 [inline] lookup_slow fs/namei.c:1809 [inline] walk_component+0x342/0x5b0 fs/namei.c:2114 lookup_last fs/namei.c:2612 [inline] path_lookupat+0x17f/0x770 fs/namei.c:2636 filename_lookup+0x221/0x5f0 fs/namei.c:2665 kern_path+0x35/0x50 fs/namei.c:2773 lookup_bdev+0xd9/0x280 block/bdev.c:1163 resume_store+0x1d8/0x460 kernel/power/hibernate.c:1247 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&of->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 seq_read_iter+0x2ab/0x12b0 fs/seq_file.c:225 kernfs_fop_read_iter+0x414/0x580 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x886/0xbf0 fs/read_write.c:565 ksys_read+0x12b/0x250 fs/read_write.c:708 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&p->lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 proc_reg_read_iter+0x21d/0x310 fs/proc/inode.c:299 copy_splice_read+0x61d/0xb80 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] do_splice_read+0x282/0x370 fs/splice.c:959 splice_file_to_pipe+0x109/0x120 fs/splice.c:1295 do_sendfile+0x3fd/0xe40 fs/read_write.c:1369 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64 fs/read_write.c:1410 [inline] __x64_sys_sendfile64+0x1da/0x220 fs/read_write.c:1410 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &p->lock --> sb_writers#6 --> &pipe->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex); lock(sb_writers#6); lock(&pipe->mutex); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz.4.3544/16863: #0: ffff888024a08868 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock fs/pipe.c:92 [inline] #0: ffff888024a08868 (&pipe->mutex){+.+.}-{4:4}, at: pipe_lock+0x64/0x80 fs/pipe.c:89 stack backtrace: CPU: 1 UID: 0 PID: 16863 Comm: syz.4.3544 Not tainted 6.14.0-rc6-syzkaller-00007-g0b46b049d6ec #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 proc_reg_read_iter+0x21d/0x310 fs/proc/inode.c:299 copy_splice_read+0x61d/0xb80 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] do_splice_read+0x282/0x370 fs/splice.c:959 splice_file_to_pipe+0x109/0x120 fs/splice.c:1295 do_sendfile+0x3fd/0xe40 fs/read_write.c:1369 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64 fs/read_write.c:1410 [inline] __x64_sys_sendfile64+0x1da/0x220 fs/read_write.c:1410 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa5f618d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa5f3ff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fa5f63a5fa0 RCX: 00007fa5f618d169 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007fa5f620e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 01fffe0000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa5f63a5fa0 R15: 00007ffc07b99168