On Sun, Apr 7, 2024 at 9:37 PM syzbot <syzbot+5e130dffef394d3f11a6@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=15f706ad180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a > dashboard link: https://syzkaller.appspot.com/bug?extid=5e130dffef394d3f11a6 > 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+5e130dffef394d3f11a6@xxxxxxxxxxxxxxxxxxxxxxxxx > > ====================================================== > WARNING: possible circular locking dependency detected > 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted > ------------------------------------------------------ > syz-executor.4/8594 is trying to acquire lock: > ffff88805d9aff38 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:654 [inline] > ffff88805d9aff38 (&ovl_i_lock_key[depth]){+.+.}-{3:3}, at: ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:719 > > but task is already holding lock: > ffff88805d9afb80 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline] > ffff88805d9afb80 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: vfs_rmdir+0x101/0x4c0 fs/namei.c:4198 > > which lock already depends on the new lock. > > > the existing dependency chain (in reverse order) is: > > -> #2 (&ovl_i_mutex_dir_key[depth]){++++}-{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 > > -> #1 (&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_fop_llseek+0x7e/0x2a0 fs/kernfs/file.c:867 > ovl_llseek+0x314/0x470 fs/overlayfs/file.c:218 > vfs_llseek fs/read_write.c:289 [inline] > ksys_lseek fs/read_write.c:302 [inline] > __do_sys_lseek fs/read_write.c:313 [inline] > __se_sys_lseek fs/read_write.c:311 [inline] > __x64_sys_lseek+0x153/0x1e0 fs/read_write.c:311 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > > -> #0 (&ovl_i_lock_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 > __mutex_lock_common kernel/locking/mutex.c:608 [inline] > __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 > ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:654 [inline] > ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:719 > ovl_copy_up_one fs/overlayfs/copy_up.c:1161 [inline] > ovl_copy_up_flags+0xbb6/0x4450 fs/overlayfs/copy_up.c:1223 > ovl_nlink_start+0x9f/0x390 fs/overlayfs/util.c:1157 > ovl_do_remove+0x1fa/0xd90 fs/overlayfs/dir.c:893 > vfs_rmdir+0x367/0x4c0 fs/namei.c:4209 > do_rmdir+0x3b5/0x580 fs/namei.c:4268 > __do_sys_rmdir fs/namei.c:4287 [inline] > __se_sys_rmdir fs/namei.c:4285 [inline] > __x64_sys_rmdir+0x49/0x60 fs/namei.c:4285 > 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_lock_key[depth] --> &of->mutex --> &ovl_i_mutex_dir_key[depth] > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(&ovl_i_mutex_dir_key[depth]); > lock(&of->mutex); > lock(&ovl_i_mutex_dir_key[depth]); > lock(&ovl_i_lock_key[depth]); > > *** DEADLOCK *** > > 3 locks held by syz-executor.4/8594: > #0: ffff88802c9d8420 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:409 > #1: ffff88805d9aa450 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:828 [inline] > #1: ffff88805d9aa450 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{3:3}, at: do_rmdir+0x263/0x580 fs/namei.c:4256 > #2: ffff88805d9afb80 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline] > #2: ffff88805d9afb80 (&ovl_i_mutex_dir_key[depth]){++++}-{3:3}, at: vfs_rmdir+0x101/0x4c0 fs/namei.c:4198 > > stack backtrace: > CPU: 0 PID: 8594 Comm: syz-executor.4 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 > __mutex_lock_common kernel/locking/mutex.c:608 [inline] > __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 > ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:654 [inline] > ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:719 > ovl_copy_up_one fs/overlayfs/copy_up.c:1161 [inline] > ovl_copy_up_flags+0xbb6/0x4450 fs/overlayfs/copy_up.c:1223 > ovl_nlink_start+0x9f/0x390 fs/overlayfs/util.c:1157 > ovl_do_remove+0x1fa/0xd90 fs/overlayfs/dir.c:893 > vfs_rmdir+0x367/0x4c0 fs/namei.c:4209 > do_rmdir+0x3b5/0x580 fs/namei.c:4268 > __do_sys_rmdir fs/namei.c:4287 [inline] > __se_sys_rmdir fs/namei.c:4285 [inline] > __x64_sys_rmdir+0x49/0x60 fs/namei.c:4285 > do_syscall_64+0xfb/0x240 > entry_SYSCALL_64_after_hwframe+0x6d/0x75 > RIP: 0033:0x7f3be947dde9 > 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:00007f3bea1720c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 > RAX: ffffffffffffffda RBX: 00007f3be95abf80 RCX: 00007f3be947dde9 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200002c0 > RBP: 00007f3be94ca47a R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 000000000000000b R14: 00007f3be95abf80 R15: 00007ffd9e6203e8 > </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 > #syz dup: possible deadlock in kernfs_fop_llseek Thanks, Amir.
