BUG: corrupted list in p9_fd_cancelled (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1748d63e480000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=8c3250776dd0ec1b64bc
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8c3250...@syzkaller.appspotmail.com

overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off.
overlayfs: upper fs does not support tmpfile.
list_del corruption, ffff88808d0e4fb0->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:45!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 24022 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
RIP: 0010:__list_del_entry_valid.cold+0x23/0x4a lib/list_debug.c:45
Code: e8 11 43 f7 ff 0f 0b 48 89 ee 48 c7 c7 40 e4 b3 88 e8 00 43 f7 ff 0f 0b 4c 89 ea 48 89 ee 48 c7 c7 80 e3 b3 88 e8 ec 42 f7 ff <0f> 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b
RSP: 0018:ffff8880a21876b0 EFLAGS: 00010286
RAX: 000000000000004e RBX: 0000000000000005 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814dff01 RDI: ffffed1014430ec8
RBP: ffff88808d0e4fb0 R08: 000000000000004e R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: dead000000000200
R13: dead000000000100 R14: ffff88808d0e4fb8 R15: ffffffff87c31bd0
FS: 00007fd7f128c700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd7f1208718 CR3: 000000004524a000 CR4: 00000000003406f0
DR0: 0080ffff00000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
__list_del_entry include/linux/list.h:117 [inline]
list_del include/linux/list.h:125 [inline]
p9_fd_cancelled+0x71/0x230 net/9p/trans_fd.c:737
p9_client_flush+0x397/0x490 net/9p/client.c:690
p9_client_rpc+0x1203/0x1440 net/9p/client.c:797
p9_client_version net/9p/client.c:968 [inline]
p9_client_create+0xa88/0x12e0 net/9p/client.c:1068
v9fs_session_init+0x1dd/0x1770 fs/9p/v9fs.c:421
v9fs_mount+0x73/0x910 fs/9p/vfs_super.c:135
mount_fs+0xa3/0x310 fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2492 [inline]
do_mount+0x115c/0x2f50 fs/namespace.c:2822
ksys_mount+0xcf/0x130 fs/namespace.c:3038
__do_sys_mount fs/namespace.c:3052 [inline]
__se_sys_mount fs/namespace.c:3049 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3049
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fd7f2d9e0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007fd7f128c168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd7f2ebe2c0 RCX: 00007fd7f2d9e0c9
RDX: 0000000020000140 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 00007fd7f2df9ae9 R08: 0000000020000580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6e10a2df R14: 00007fd7f128c300 R15: 0000000000022000
Modules linked in:
---[ end trace cd27a6468ed388ea ]---
RIP: 0010:__list_del_entry_valid.cold+0x23/0x4a lib/list_debug.c:45
Code: e8 11 43 f7 ff 0f 0b 48 89 ee 48 c7 c7 40 e4 b3 88 e8 00 43 f7 ff 0f 0b 4c 89 ea 48 89 ee 48 c7 c7 80 e3 b3 88 e8 ec 42 f7 ff <0f> 0b 4c 89 e2 48 89 ee 48 c7 c7 e0 e3 b3 88 e8 d8 42 f7 ff 0f 0b
RSP: 0018:ffff8880a21876b0 EFLAGS: 00010286
RAX: 000000000000004e RBX: 0000000000000005 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814dff01 RDI: ffffed1014430ec8
RBP: ffff88808d0e4fb0 R08: 000000000000004e R09: 0000000000000000
overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off.
R10: 0000000000000005 R11: 0000000000000000 R12: dead000000000200
R13: dead000000000100 R14: ffff88808d0e4fb8 R15: ffffffff87c31bd0
FS: 00007fd7f128c700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd7f1208718 CR3: 000000004524a000 CR4: 00000000003406f0
DR0: 0080ffff00000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600


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