[f2fs-dev] [syzbot] [f2fs?] possible deadlock in f2fs_add_inline_entry

[syzbot <syzbot+a4976ce949df66b1ddf1@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    296d53d8f84c Add linux-next specific files for 20230703
git tree:       linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1742e724a80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5241eb40bbf2c7cf
dashboard link: https://syzkaller.appspot.com/bug?extid=a4976ce949df66b1ddf1
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17030110a80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12a2f1f0a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/86f91798abf1/disk-296d53d8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/80ef8a306265/vmlinux-296d53d8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d2faf52c9a84/bzImage-296d53d8.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/a912111147f7/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a4976ce949df66b1ddf1@syzkaller.appspotmail.com

F2FS-fs (loop0): Mounted with checkpoint version = 48b305e5
======================================================
WARNING: possible circular locking dependency detected
6.4.0-next-20230703-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor218/5030 is trying to acquire lock:
ffff8880752cb160 (&fi->i_sem){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2133 [inline]
ffff8880752cb160 (&fi->i_sem){+.+.}-{3:3}, at: f2fs_add_inline_entry+0x2c4/0x6c0 fs/f2fs/inline.c:644

but task is already holding lock:
ffff8880752c9978 (&fi->i_xattr_sem){.+.+}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2108 [inline]
ffff8880752c9978 (&fi->i_xattr_sem){.+.+}-{3:3}, at: f2fs_add_dentry+0x92/0x240 fs/f2fs/dir.c:783

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&fi->i_xattr_sem){.+.+}-{3:3}:
       down_read+0x9c/0x480 kernel/locking/rwsem.c:1520
       f2fs_down_read fs/f2fs/f2fs.h:2108 [inline]
       f2fs_getxattr+0xb96/0xfd0 fs/f2fs/xattr.c:532
       __f2fs_get_acl+0x59/0x610 fs/f2fs/acl.c:179
       f2fs_acl_create fs/f2fs/acl.c:377 [inline]
       f2fs_init_acl+0x152/0xb40 fs/f2fs/acl.c:420
       f2fs_init_inode_metadata+0x15d/0x1260 fs/f2fs/dir.c:558
       f2fs_add_regular_entry+0x776/0xb70 fs/f2fs/dir.c:740
       f2fs_add_dentry+0x1e1/0x240 fs/f2fs/dir.c:788
       f2fs_do_add_link+0x183/0x270 fs/f2fs/dir.c:827
       f2fs_add_link fs/f2fs/f2fs.h:3554 [inline]
       f2fs_mkdir+0x387/0x630 fs/f2fs/namei.c:781
       vfs_mkdir+0x242/0x460 fs/namei.c:4117
       do_mkdirat+0x28d/0x310 fs/namei.c:4140
       __do_sys_mkdir fs/namei.c:4160 [inline]
       __se_sys_mkdir fs/namei.c:4158 [inline]
       __x64_sys_mkdir+0xf6/0x140 fs/namei.c:4158
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&fi->i_sem){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3142 [inline]
       check_prevs_add kernel/locking/lockdep.c:3261 [inline]
       validate_chain kernel/locking/lockdep.c:3876 [inline]
       __lock_acquire+0x2e9d/0x5e20 kernel/locking/lockdep.c:5144
       lock_acquire kernel/locking/lockdep.c:5761 [inline]
       lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
       down_write+0x92/0x200 kernel/locking/rwsem.c:1573
       f2fs_down_write fs/f2fs/f2fs.h:2133 [inline]
       f2fs_add_inline_entry+0x2c4/0x6c0 fs/f2fs/inline.c:644
       f2fs_add_dentry+0xa6/0x240 fs/f2fs/dir.c:784
       f2fs_do_add_link+0x183/0x270 fs/f2fs/dir.c:827
       f2fs_add_link fs/f2fs/f2fs.h:3554 [inline]
       f2fs_mkdir+0x387/0x630 fs/f2fs/namei.c:781
       vfs_mkdir+0x242/0x460 fs/namei.c:4117
       ovl_do_mkdir fs/overlayfs/overlayfs.h:196 [inline]
       ovl_mkdir_real+0xbc/0x390 fs/overlayfs/dir.c:146
       ovl_workdir_create+0x3d2/0x900 fs/overlayfs/super.c:309
       ovl_make_workdir fs/overlayfs/super.c:711 [inline]
       ovl_get_workdir fs/overlayfs/super.c:864 [inline]
       ovl_fill_super+0xcb6/0x5c90 fs/overlayfs/super.c:1400
       vfs_get_super+0xea/0x280 fs/super.c:1152
       vfs_get_tree+0x8d/0x350 fs/super.c:1519
       do_new_mount fs/namespace.c:3335 [inline]
       path_mount+0x136e/0x1e70 fs/namespace.c:3662
       do_mount fs/namespace.c:3675 [inline]
       __do_sys_mount fs/namespace.c:3884 [inline]
       __se_sys_mount fs/namespace.c:3861 [inline]
       __x64_sys_mount+0x283/0x300 fs/namespace.c:3861
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&fi->i_xattr_sem);
                               lock(&fi->i_sem);
                               lock(&fi->i_xattr_sem);
  lock(&fi->i_sem);

 *** DEADLOCK ***

5 locks held by syz-executor218/5030:
 #0: ffff8880780d60e0 (&type->s_umount_key#42/1){+.+.}-{3:3}, at: alloc_super+0x22e/0xb40 fs/super.c:228
 #1: ffff8880271d6410 (sb_writers#9){.+.+}-{0:0}, at: ovl_make_workdir fs/overlayfs/super.c:707 [inline]
 #1: ffff8880271d6410 (sb_writers#9){.+.+}-{0:0}, at: ovl_get_workdir fs/overlayfs/super.c:864 [inline]
 #1: ffff8880271d6410 (sb_writers#9){.+.+}-{0:0}, at: ovl_fill_super+0xc8d/0x5c90 fs/overlayfs/super.c:1400
 #2: ffff8880752c9300 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:806 [inline]
 #2: ffff8880752c9300 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: ovl_workdir_create+0x137/0x900 fs/overlayfs/super.c:281
 #3: ffff8880786603b0 (&sbi->cp_rwsem){.+.+}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2108 [inline]
 #3: ffff8880786603b0 (&sbi->cp_rwsem){.+.+}-{3:3}, at: f2fs_lock_op fs/f2fs/f2fs.h:2151 [inline]
 #3: ffff8880786603b0 (&sbi->cp_rwsem){.+.+}-{3:3}, at: f2fs_mkdir+0x2a2/0x630 fs/f2fs/namei.c:780
 #4: ffff8880752c9978 (&fi->i_xattr_sem){.+.+}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2108 [inline]
 #4: ffff8880752c9978 (&fi->i_xattr_sem){.+.+}-{3:3}, at: f2fs_add_dentry+0x92/0x240 fs/f2fs/dir.c:783

stack backtrace:
CPU: 0 PID: 5030 Comm: syz-executor218 Not tainted 6.4.0-next-20230703-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 check_noncircular+0x2df/0x3b0 kernel/locking/lockdep.c:2195
 check_prev_add kernel/locking/lockdep.c:3142 [inline]
 check_prevs_add kernel/locking/lockdep.c:3261 [inline]
 validate_chain kernel/locking/lockdep.c:3876 [inline]
 __lock_acquire+0x2e9d/0x5e20 kernel/locking/lockdep.c:5144
 lock_acquire kernel/locking/lockdep.c:5761 [inline]
 lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
 down_write+0x92/0x200 kernel/locking/rwsem.c:1573
 f2fs_down_write fs/f2fs/f2fs.h:2133 [inline]
 f2fs_add_inline_entry+0x2c4/0x6c0 fs/f2fs/inline.c:644
 f2fs_add_dentry+0xa6/0x240 fs/f2fs/dir.c:784
 f2fs_do_add_link+0x183/0x270 fs/f2fs/dir.c:827
 f2fs_add_link fs/f2fs/f2fs.h:3554 [inline]
 f2fs_mkdir+0x387/0x630 fs/f2fs/namei.c:781
 vfs_mkdir+0x242/0x460 fs/namei.c:4117
 ovl_do_mkdir fs/overlayfs/overlayfs.h:196 [inline]
 ovl_mkdir_real+0xbc/0x390 fs/overlayfs/dir.c:146
 ovl_workdir_create+0x3d2/0x900 fs/overlayfs/super.c:309
 ovl_make_workdir fs/overlayfs/super.c:711 [inline]
 ovl_get_workdir fs/overlayfs/super.c:864 [inline]
 ovl_fill_super+0xcb6/0x5c90 fs/overlayfs/super.c:1400
 vfs_get_super+0xea/0x280 fs/super.c:1152
 vfs_get_tree+0x8d/0x350 fs/super.c:1519
 do_new_mount fs/namespace.c:3335 [inline]
 path_mount+0x136e/0x1e70 fs/namespace.c:3662
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount fs/namespace.c:3861 [inline]
 __x64_sys_mount+0x283/0x300 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0b7b784909
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcdf3d7158 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f0b7b784909
RDX: 0000000020000280 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 00007f0b7b7441a0 R08: 0000000020000180 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0b7b744230
R13: 0000000


---
This report is generated by a bot. It may contain errors.
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If the bug is already fixed, let syzbot know by replying with:
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