====================================================== WARNING: possible circular locking dependency detected 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0 Not tainted ------------------------------------------------------ syz.0.2542/15091 is trying to acquire lock: ffff888047e58cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:809 [inline] ffff888047e58cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: lookup_slow fs/namei.c:1734 [inline] ffff888047e58cf8 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: walk_component+0x342/0x5b0 fs/namei.c:2039 but task is already holding lock: ffff8880484c6488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x281/0x500 fs/kernfs/file.c:325 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&of->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 kernfs_fop_write_iter+0x281/0x500 fs/kernfs/file.c:325 iter_file_splice_write+0x906/0x10b0 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] do_splice+0x148c/0x1f90 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice fs/splice.c:1634 [inline] __x64_sys_splice+0x1d2/0x260 fs/splice.c:1634 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 (&pipe->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752 pipe_lock fs/pipe.c:92 [inline] pipe_lock+0x64/0x80 fs/pipe.c:89 iter_file_splice_write+0x1f0/0x10b0 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0x148c/0x1f90 fs/splice.c:1354 __do_splice+0x327/0x360 fs/splice.c:1436 __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice fs/splice.c:1634 [inline] __x64_sys_splice+0x1d2/0x260 fs/splice.c:1634 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 (sb_writers#6){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1675 [inline] sb_start_write include/linux/fs.h:1811 [inline] mnt_want_write+0x6f/0x450 fs/namespace.c:515 ovl_create_object+0x12e/0x300 fs/overlayfs/dir.c:642 lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3578 open_last_lookups fs/namei.c:3647 [inline] path_openat+0xa3b/0x2d20 fs/namei.c:3883 do_filp_open+0x1dc/0x430 fs/namei.c:3913 do_sys_openat2+0x17a/0x1e0 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1442 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 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 down_read+0x9a/0x330 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:809 [inline] lookup_slow fs/namei.c:1734 [inline] walk_component+0x342/0x5b0 fs/namei.c:2039 lookup_last fs/namei.c:2542 [inline] path_lookupat+0x17f/0x770 fs/namei.c:2566 filename_lookup+0x1e5/0x5b0 fs/namei.c:2595 kern_path+0x35/0x50 fs/namei.c:2703 lookup_bdev+0xd9/0x280 block/bdev.c:1157 resume_store+0x1d8/0x460 kernel/power/hibernate.c:1235 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x343/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 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: &ovl_i_mutex_dir_key[depth] --> &pipe->mutex --> &of->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&of->mutex); lock(&pipe->mutex); lock(&of->mutex); rlock(&ovl_i_mutex_dir_key[depth]); *** DEADLOCK *** 4 locks held by syz.0.2542/15091: #0: ffff8880298c19c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xeb/0x180 fs/file.c:1187 #1: ffff888024928420 (sb_writers#9){.+.+}-{0:0}, at: ksys_write+0x12f/0x260 fs/read_write.c:643 #2: ffff8880484c6488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x281/0x500 fs/kernfs/file.c:325 #3: ffff888016744698 (kn->active#77){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2a4/0x500 fs/kernfs/file.c:326 stack backtrace: CPU: 1 UID: 0 PID: 15091 Comm: syz.0.2542 Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #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:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x24ed/0x3cb0 kernel/locking/lockdep.c:5142 lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 down_read+0x9a/0x330 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:809 [inline] lookup_slow fs/namei.c:1734 [inline] walk_component+0x342/0x5b0 fs/namei.c:2039 lookup_last fs/namei.c:2542 [inline] path_lookupat+0x17f/0x770 fs/namei.c:2566 filename_lookup+0x1e5/0x5b0 fs/namei.c:2595 kern_path+0x35/0x50 fs/namei.c:2703 lookup_bdev+0xd9/0x280 block/bdev.c:1157 resume_store+0x1d8/0x460 kernel/power/hibernate.c:1235 kobj_attr_store+0x55/0x80 lib/kobject.c:840 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x343/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6b6/0x1140 fs/read_write.c:590 ksys_write+0x12f/0x260 fs/read_write.c:643 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: 0033:0x7efcd1f799f9 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:00007efcd2d56038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007efcd2115f80 RCX: 00007efcd1f799f9 RDX: 0000000000000012 RSI: 0000000020000140 RDI: 0000000000000009 RBP: 00007efcd1fe78ee R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007efcd2115f80 R15: 00007ffdbb59c4e8 PM: Image not found (code -6)