And this one too. #syz dup: possible deadlock in kernfs_fop_llseek On Mon, 8 Apr 2024 at 13:49, syzbot <syzbot+ac3c5eb32b9d409dc11d@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17adb6d3180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a > dashboard link: https://syzkaller.appspot.com/bug?extid=ac3c5eb32b9d409dc11d > 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/72ab73815344/disk-fe46a7dd.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/2d6d6b0d7071/vmlinux-fe46a7dd.xz > kernel image: https://storage.googleapis.com/syzbot-assets/48e275e5478b/bzImage-fe46a7dd.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ac3c5eb32b9d409dc11d@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted > ------------------------------------------------------ > syz-executor.1/9023 is trying to acquire lock: > ffff88805d610740 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:803 [inline] > ffff88805d610740 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: lookup_slow fs/namei.c:1708 [inline] > ffff88805d610740 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: lookup_one_unlocked+0x197/0x290 fs/namei.c:2817 > > but task is already holding lock: > ffff88805d612450 (&ovl_i_mutex_dir_key[depth]#3){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:803 [inline] > ffff88805d612450 (&ovl_i_mutex_dir_key[depth]#3){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #5 (&ovl_i_mutex_dir_key[depth]#3){.+.+}-{3:3}: > lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 > down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 > inode_lock_shared include/linux/fs.h:803 [inline] > lookup_slow+0x45/0x70 fs/namei.c:1708 > walk_component+0x2e1/0x410 fs/namei.c:2004 > lookup_last fs/namei.c:2461 [inline] > path_lookupat+0x16f/0x450 fs/namei.c:2485 > filename_lookup+0x256/0x610 fs/namei.c:2514 > kern_path+0x35/0x50 fs/namei.c:2622 > lookup_bdev+0xc5/0x290 block/bdev.c:1072 > resume_store+0x1a0/0x710 kernel/power/hibernate.c:1235 > kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 > call_write_iter include/linux/fs.h:2108 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa84/0xcb0 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > -> #4 (&of->mutex){+.+.}-{3:3}: > lock_acquire+0x1e4/0x530 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:2102 [inline] > new_sync_read fs/read_write.c:395 [inline] > vfs_read+0x97b/0xb70 fs/read_write.c:476 > ksys_read+0x1a0/0x2c0 fs/read_write.c:619 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > -> #3 (&p->lock){+.+.}-{3:3}: > lock_acquire+0x1e4/0x530 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 > call_read_iter include/linux/fs.h:2102 [inline] > copy_splice_read+0x662/0xb60 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:1362 [inline] > __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > -> #2 (&pipe->mutex){+.+.}-{3:3}: > lock_acquire+0x1e4/0x530 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+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > -> #1 (sb_writers#4){.+.+}-{0:0}: > lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 > percpu_down_read include/linux/percpu-rwsem.h:51 [inline] > __sb_start_write include/linux/fs.h:1662 [inline] > sb_start_write+0x4d/0x1c0 include/linux/fs.h:1798 > mnt_want_write+0x3f/0x90 fs/namespace.c:409 > ovl_create_object+0x13b/0x370 fs/overlayfs/dir.c:629 > lookup_open fs/namei.c:3497 [inline] > open_last_lookups fs/namei.c:3566 [inline] > path_openat+0x1425/0x3240 fs/namei.c:3796 > do_filp_open+0x235/0x490 fs/namei.c:3826 > do_sys_openat2+0x13e/0x1d0 fs/open.c:1406 > do_sys_open fs/open.c:1421 [inline] > __do_sys_open fs/open.c:1429 [inline] > __se_sys_open fs/open.c:1425 [inline] > __x64_sys_open+0x225/0x270 fs/open.c:1425 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > -> #0 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}: > check_prev_add kernel/locking/lockdep.c:3134 [inline] > check_prevs_add kernel/locking/lockdep.c:3253 [inline] > validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 > __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 > lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 > down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 > inode_lock_shared include/linux/fs.h:803 [inline] > lookup_slow fs/namei.c:1708 [inline] > lookup_one_unlocked+0x197/0x290 fs/namei.c:2817 > ovl_lookup_positive_unlocked fs/overlayfs/namei.c:210 [inline] > ovl_lookup_single+0x200/0xbd0 fs/overlayfs/namei.c:240 > ovl_lookup_layer+0x417/0x510 fs/overlayfs/namei.c:333 > ovl_lookup+0xcf7/0x2a60 fs/overlayfs/namei.c:1124 > __lookup_slow+0x28c/0x3f0 fs/namei.c:1692 > lookup_slow+0x53/0x70 fs/namei.c:1709 > walk_component+0x2e1/0x410 fs/namei.c:2004 > lookup_last fs/namei.c:2461 [inline] > path_lookupat+0x16f/0x450 fs/namei.c:2485 > filename_lookup+0x256/0x610 fs/namei.c:2514 > kern_path+0x35/0x50 fs/namei.c:2622 > lookup_bdev+0xc5/0x290 block/bdev.c:1072 > resume_store+0x1a0/0x710 kernel/power/hibernate.c:1235 > kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 > call_write_iter include/linux/fs.h:2108 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa84/0xcb0 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > other info that might help us debug this: > > Chain exists of: > &ovl_i_mutex_dir_key[depth] --> &of->mutex --> &ovl_i_mutex_dir_key[depth]#3 > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > rlock(&ovl_i_mutex_dir_key[depth]#3); > lock(&of->mutex); > lock(&ovl_i_mutex_dir_key[depth]#3); > rlock(&ovl_i_mutex_dir_key[depth]); > > *** DEADLOCK *** > > 5 locks held by syz-executor.1/9023: > #0: ffff888059ebf248 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x259/0x320 fs/file.c:1191 > #1: ffff88802f972420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2853 [inline] > #1: ffff88802f972420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 > #2: ffff88801edfd088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325 > #3: ffff888019281918 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326 > #4: ffff88805d612450 (&ovl_i_mutex_dir_key[depth]#3){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:803 [inline] > #4: ffff88805d612450 (&ovl_i_mutex_dir_key[depth]#3){.+.+}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1708 > > stack backtrace: > CPU: 1 PID: 9023 Comm: syz-executor.1 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:88 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 > 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+0x18cb/0x58e0 kernel/locking/lockdep.c:3869 > __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137 > lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754 > down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526 > inode_lock_shared include/linux/fs.h:803 [inline] > lookup_slow fs/namei.c:1708 [inline] > lookup_one_unlocked+0x197/0x290 fs/namei.c:2817 > ovl_lookup_positive_unlocked fs/overlayfs/namei.c:210 [inline] > ovl_lookup_single+0x200/0xbd0 fs/overlayfs/namei.c:240 > ovl_lookup_layer+0x417/0x510 fs/overlayfs/namei.c:333 > ovl_lookup+0xcf7/0x2a60 fs/overlayfs/namei.c:1124 > __lookup_slow+0x28c/0x3f0 fs/namei.c:1692 > lookup_slow+0x53/0x70 fs/namei.c:1709 > walk_component+0x2e1/0x410 fs/namei.c:2004 > lookup_last fs/namei.c:2461 [inline] > path_lookupat+0x16f/0x450 fs/namei.c:2485 > filename_lookup+0x256/0x610 fs/namei.c:2514 > kern_path+0x35/0x50 fs/namei.c:2622 > lookup_bdev+0xc5/0x290 block/bdev.c:1072 > resume_store+0x1a0/0x710 kernel/power/hibernate.c:1235 > kernfs_fop_write_iter+0x3a4/0x500 fs/kernfs/file.c:334 > call_write_iter include/linux/fs.h:2108 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa84/0xcb0 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > RIP: 0033:0x7f389687de69 > 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:00007f38963ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007f38969abf80 RCX: 00007f389687de69 > RDX: 0000000000000012 RSI: 0000000020000000 RDI: 0000000000000006 > RBP: 00007f38968ca47a R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 000000000000000b R14: 00007f38969abf80 R15: 00007ffca27d9338 > </TASK> > PM: Image not found (code -6) > > > --- > 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 >
