Hello, syzbot found the following issue on: HEAD commit: 841c35169323 Linux 6.8-rc4 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1215e120180000 kernel config: https://syzkaller.appspot.com/x/.config?x=fbd950b5071b7ea3 dashboard link: https://syzkaller.appspot.com/bug?extid=af9aa785e14a67796a87 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/ef821afd15d3/disk-841c3516.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e41102f18e6e/vmlinux-841c3516.xz kernel image: https://storage.googleapis.com/syzbot-assets/a17352b259d8/bzImage-841c3516.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+af9aa785e14a67796a87@xxxxxxxxxxxxxxxxxxxxxxxxx F2FS-fs (loop1): Found nat_bits in checkpoint F2FS-fs (loop1): Mounted with checkpoint version = 48b305e5 ====================================================== WARNING: possible circular locking dependency detected 6.8.0-rc4-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/640 is trying to acquire lock: ffff888072750310 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 but task is already holding lock: ffff888023f61c68 (&pipe->mutex/1){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&pipe->mutex/1){+.+.}-{3:3}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 iter_file_splice_write+0x335/0x14e0 fs/splice.c:687 do_splice_from fs/splice.c:941 [inline] do_splice+0xd77/0x1880 fs/splice.c:1354 __do_splice fs/splice.c:1436 [inline] __do_sys_splice fs/splice.c:1652 [inline] __se_sys_splice+0x331/0x4a0 fs/splice.c:1634 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #3 (sb_writers#4){.+.+}-{0:0}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1639 [inline] sb_start_write+0x4d/0x1c0 include/linux/fs.h:1775 mnt_want_write+0x3f/0x90 fs/namespace.c:409 ovl_fix_origin fs/overlayfs/namei.c:908 [inline] ovl_lookup+0x1394/0x2a60 fs/overlayfs/namei.c:1143 __lookup_slow+0x28c/0x3f0 fs/namei.c:1693 lookup_slow+0x53/0x70 fs/namei.c:1710 walk_component fs/namei.c:2001 [inline] link_path_walk+0x9cd/0xe80 fs/namei.c:2328 path_lookupat+0xa9/0x450 fs/namei.c:2481 filename_lookup+0x255/0x610 fs/namei.c:2511 user_path_at_empty+0x42/0x60 fs/namei.c:2920 user_path_at include/linux/namei.h:57 [inline] __do_sys_chdir fs/open.c:556 [inline] __se_sys_chdir+0xbf/0x220 fs/open.c:550 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 inode_lock_shared include/linux/fs.h:812 [inline] lookup_slow+0x45/0x70 fs/namei.c:1709 walk_component+0x2e1/0x410 fs/namei.c:2001 lookup_last fs/namei.c:2458 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2482 filename_lookup+0x255/0x610 fs/namei.c:2511 kern_path+0x35/0x50 fs/namei.c:2619 lookup_bdev+0xc5/0x290 block/bdev.c:1014 resume_store+0x1a0/0x710 kernel/power/hibernate.c:1183 kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:2085 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa81/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #1 (&of->mutex){+.+.}-{3:3}: lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 seq_read_iter+0x3d0/0xd60 fs/seq_file.c:225 call_read_iter include/linux/fs.h:2079 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x978/0xb70 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 -> #0 (&p->lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 proc_reg_read_iter+0x1c3/0x290 fs/proc/inode.c:302 call_read_iter include/linux/fs.h:2079 [inline] copy_splice_read+0x661/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x299/0x500 fs/splice.c:1295 do_sendfile+0x515/0xdc0 fs/read_write.c:1301 __do_sys_sendfile64 fs/read_write.c:1356 [inline] __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1348 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 other info that might help us debug this: Chain exists of: &p->lock --> sb_writers#4 --> &pipe->mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&pipe->mutex/1); lock(sb_writers#4); lock(&pipe->mutex/1); lock(&p->lock); *** DEADLOCK *** 1 lock held by syz-executor.1/640: #0: ffff888023f61c68 (&pipe->mutex/1){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 stack backtrace: CPU: 1 PID: 640 Comm: syz-executor.1 Not tainted 6.8.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain+0x18ca/0x58e0 kernel/locking/lockdep.c:3869 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 proc_reg_read_iter+0x1c3/0x290 fs/proc/inode.c:302 call_read_iter include/linux/fs.h:2079 [inline] copy_splice_read+0x661/0xb60 fs/splice.c:365 do_splice_read fs/splice.c:985 [inline] splice_file_to_pipe+0x299/0x500 fs/splice.c:1295 do_sendfile+0x515/0xdc0 fs/read_write.c:1301 __do_sys_sendfile64 fs/read_write.c:1356 [inline] __se_sys_sendfile64+0x100/0x1e0 fs/read_write.c:1348 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f3acde7dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3acec5e0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f3acdfac050 RCX: 00007f3acde7dda9 RDX: 0000000020000000 RSI: 0000000000000004 RDI: 0000000000000000 RBP: 00007f3acdeca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f3acdfac050 R15: 00007fff9463d788 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
