+cc overlayfs > On Feb 8, 2025, at 17:14, syzbot <syzbot+7836a68852a10ec3d790@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > syzbot has found a reproducer for the following issue on: > > HEAD commit: 7ee983c850b4 Merge tag 'drm-fixes-2025-02-08' of https://g.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=17375ca4580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=1909f2f0d8e641ce > dashboard link: https://syzkaller.appspot.com/bug?extid=7836a68852a10ec3d790 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14e0cca4580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=155361b0580000 > > Downloadable assets: > disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-7ee983c8.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/f2f78699fc41/vmlinux-7ee983c8.xz > kernel image: https://storage.googleapis.com/syzbot-assets/ca55e6e8dd01/bzImage-7ee983c8.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/aa79c539b21d/mount_0.gz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+7836a68852a10ec3d790@xxxxxxxxxxxxxxxxxxxxxxxxx > > bcachefs (loop0): reading snapshots table > bcachefs (loop0): reading snapshots done > bcachefs (loop0): done starting filesystem > ============================================ > WARNING: possible recursive locking detected > 6.14.0-rc1-syzkaller-00181-g7ee983c850b4 #0 Not tainted > -------------------------------------------- > syz-executor294/5305 is trying to acquire lock: > ffff888044775078 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] > ffff888044775078 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:839 > > but task is already holding lock: > ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] > ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] > ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] > ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] > ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_copy_up_flags+0x19cb/0x47c0 fs/overlayfs/copy_up.c:1257 > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(&sb->s_type->i_mutex_key#16); > lock(&sb->s_type->i_mutex_key#16); > > *** DEADLOCK *** > > May be due to missing lock nesting notation > > 7 locks held by syz-executor294/5305: > #0: ffff88801df94420 (sb_writers#10){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547 > #1: ffff88804470de50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:912 [inline] > #1: ffff88804470de50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3217 [inline] > #1: ffff88804470de50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: do_renameat2+0x62c/0x13f0 fs/namei.c:5161 > #2: ffff88804470e418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] > #2: ffff88804470e418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: lock_two_nondirectories+0xe1/0x170 fs/inode.c:1281 > #3: ffff88804470e9e0 (&ovl_i_mutex_key[depth]/4){+.+.}-{4:4}, at: vfs_rename+0x6a2/0xf00 fs/namei.c:5040 > #4: ffff88804470e7d0 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:650 [inline] > #4: ffff88804470e7d0 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:727 > #5: ffff8880477b0420 (sb_writers#9){.+.+}-{0:0}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:781 [inline] > #5: ffff8880477b0420 (sb_writers#9){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] > #5: ffff8880477b0420 (sb_writers#9){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] > #5: ffff8880477b0420 (sb_writers#9){.+.+}-{0:0}, at: ovl_copy_up_flags+0x19b4/0x47c0 fs/overlayfs/copy_up.c:1257 > #6: ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] > #6: ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] > #6: ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] > #6: ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] > #6: ffff888044774148 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: ovl_copy_up_flags+0x19cb/0x47c0 fs/overlayfs/copy_up.c:1257 > > stack backtrace: > CPU: 0 UID: 0 PID: 5305 Comm: syz-executor294 Not tainted 6.14.0-rc1-syzkaller-00181-g7ee983c850b4 #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: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3039 > check_deadlock kernel/locking/lockdep.c:3091 [inline] > validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893 > __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 > lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 > down_write+0x99/0x220 kernel/locking/rwsem.c:1577 > inode_lock include/linux/fs.h:877 [inline] > bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:839 > vfs_symlink+0x137/0x2e0 fs/namei.c:4671 > ovl_do_symlink+0x85/0xd0 fs/overlayfs/overlayfs.h:267 > ovl_create_real+0x346/0x550 fs/overlayfs/dir.c:206 > ovl_copy_up_workdir fs/overlayfs/copy_up.c:783 [inline] > ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] > ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] > ovl_copy_up_flags+0x19fe/0x47c0 fs/overlayfs/copy_up.c:1257 > ovl_rename+0x62a/0x1760 fs/overlayfs/dir.c:1150 > vfs_rename+0xbdb/0xf00 fs/namei.c:5069 > do_renameat2+0xd94/0x13f0 fs/namei.c:5226 > __do_sys_rename fs/namei.c:5273 [inline] > __se_sys_rename fs/namei.c:5271 [inline] > __x64_sys_rename+0x82/0x90 fs/namei.c:5271 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f0d8dddad19 > Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 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 b8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffd9dbea2d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 > RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007f0d8dddad19 > RDX: 00007f0d8dddad19 RSI: 0000400000000840 RDI: 0000400000000800 > RBP: 0031656c69662f2e R08: 000055558454d4c0 R09: 000055558454d4c0 > R10: 000055558454d4c0 R11: 0000000000000246 R12: 00007ffd9dbea300 > R13: 00007ffd9dbea528 R14: 431bde82d7b634db R15: 00007f0d8de2303b > </TASK> > syz-executor294 (5305) used greatest stack depth: 10768 bytes left > > > --- > If you want syzbot to run the reproducer, reply with: > #syz test: git://repo/address.git branch-or-commit-hash > If you attach or paste a git patch, syzbot will apply it before testing. >
