Re: [syzbot] [nilfs?] [mm?] KASAN: slab-use-after-free Read in lru_add_fn

[syzbot <syzbot+d79afb004be235636ee8@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
VFS: Busy inodes after unmount (use-after-free)

Buffer I/O error on dev loop0, logical block 1020, lost sync page write
NILFS (loop0): unable to write superblock: err=-5
Buffer I/O error on dev loop0, logical block 1, lost sync page write
NILFS (loop0): unable to write superblock: err=-5
VFS: Busy inodes after unmount of loop0 (nilfs2)
------------[ cut here ]------------
kernel BUG at fs/super.c:650!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 1 PID: 5332 Comm: syz-executor Not tainted 6.10.0-rc3-syzkaller-gcea2a26553ac-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:generic_shutdown_super+0x31b/0x3d0 fs/super.c:650
Code: 28 48 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 aa 00 00 00 48 8b 55 00 48 8d b3 68 06 00 00 48 c7 c7 40 2c 3d 8b e8 36 5e 74 ff 90 <0f> 0b e8 de c2 ef ff e9 2f fd ff ff e8 d4 c2 ef ff e9 02 fd ff ff
RSP: 0018:ffffc900037efd90 EFLAGS: 00010282
RAX: 0000000000000030 RBX: ffff888034e72000 RCX: ffffffff816e69b9
RDX: 0000000000000000 RSI: ffffffff816ef706 RDI: 0000000000000005
RBP: ffffffff8e268620 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffff888034e729c0
R13: ffff888034e72780 R14: 0000000000000000 R15: ffff888026ba4900
FS:  0000555556270480(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b072ff000 CR3: 0000000015ff6000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kill_block_super+0x3b/0x90 fs/super.c:1676
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
 deactivate_super+0xde/0x100 fs/super.c:506
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b1047e217
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc7e659328 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007f7b1047e217
RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffc7e65a4d0
RBP: 00007f7b104c8336 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000202 R12: 00007ffc7e65a4d0
R13: 00007f7b104c8336 R14: 0000555556270430 R15: 0000000000000005
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:generic_shutdown_super+0x31b/0x3d0 fs/super.c:650
Code: 28 48 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 aa 00 00 00 48 8b 55 00 48 8d b3 68 06 00 00 48 c7 c7 40 2c 3d 8b e8 36 5e 74 ff 90 <0f> 0b e8 de c2 ef ff e9 2f fd ff ff e8 d4 c2 ef ff e9 02 fd ff ff
RSP: 0018:ffffc900037efd90 EFLAGS: 00010282
RAX: 0000000000000030 RBX: ffff888034e72000 RCX: ffffffff816e69b9
RDX: 0000000000000000 RSI: ffffffff816ef706 RDI: 0000000000000005
RBP: ffffffff8e268620 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffff888034e729c0
R13: ffff888034e72780 R14: 0000000000000000 R15: ffff888026ba4900
FS:  0000555556270480(0000) GS:ffff88806b000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc7e658b78 CR3: 0000000015ff6000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         cea2a265 mailmap: Add my outdated addresses to the map..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=15c16d7a980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b8786f381e62940f
dashboard link: https://syzkaller.appspot.com/bug?extid=d79afb004be235636ee8
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13182c0e980000