Re: [syzbot] WARNING in p9_client_destroy

From: syzbot
Date: Mon Jul 25 2022 - 07:33:15 EST


Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: trying to register non-static key in p9_req_free

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 4084 Comm: syz-executor.0 Not tainted 5.19.0-rc4-next-20220628-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
assign_lock_key kernel/locking/lockdep.c:979 [inline]
register_lock_class+0xf30/0x1130 kernel/locking/lockdep.c:1292
__lock_acquire+0x10a/0x5660 kernel/locking/lockdep.c:4932
lock_acquire kernel/locking/lockdep.c:5665 [inline]
lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
complete+0x19/0x1f0 kernel/sched/completion.c:32
p9_req_free+0x16d/0x1d0 net/9p/client.c:385
kref_put include/linux/kref.h:65 [inline]
p9_req_put net/9p/client.c:390 [inline]
p9_tag_remove+0xe2/0x120 net/9p/client.c:372
p9_client_version net/9p/client.c:999 [inline]
p9_client_create+0xc5f/0x1100 net/9p/client.c:1062
v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408
v9fs_mount+0x73/0xa80 fs/9p/vfs_super.c:126
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1501
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1320/0x1fa0 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fc4c8e89209
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007fc4c9fd0168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc4c8f9bf60 RCX: 00007fc4c8e89209
RDX: 0000000020000140 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 00007fc4c8ee3161 R08: 0000000020000580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdb94b6f3f R14: 00007fc4c9fd0300 R15: 0000000000022000
</TASK>
BUG: unable to handle page fault for address: fffffffffffffff8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD ba8f067 P4D ba8f067 PUD ba91067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4084 Comm: syz-executor.0 Not tainted 5.19.0-rc4-next-20220628-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:swake_up_locked kernel/sched/swait.c:29 [inline]
RIP: 0010:swake_up_locked kernel/sched/swait.c:21 [inline]
RIP: 0010:complete+0x98/0x1f0 kernel/sched/completion.c:36
Code: e0 0f 84 f7 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 48 48 8d 7b f8 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 03 01 00 00 <48> 8b 7b f8 4c 8d 63 08 e8 8b 74 f8 ff 48 89 df e8 e3 79 a3 02 84
RSP: 0018:ffffc900030af978 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff815f0600
RDX: 1fffffffffffffff RSI: 0000000000000004 RDI: fffffffffffffff8
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000615f1d R11: 3e4b5341542f3c20 R12: ffff88806ef26cb8
R13: ffff88806ef26c78 R14: ffff8880205a6000 R15: ffff88806ef26c48
FS: 00007fc4c9fd0700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff8 CR3: 0000000078de1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
p9_req_free+0x16d/0x1d0 net/9p/client.c:385
kref_put include/linux/kref.h:65 [inline]
p9_req_put net/9p/client.c:390 [inline]
p9_tag_remove+0xe2/0x120 net/9p/client.c:372
p9_client_version net/9p/client.c:999 [inline]
p9_client_create+0xc5f/0x1100 net/9p/client.c:1062
v9fs_session_init+0x1e2/0x1810 fs/9p/v9fs.c:408
v9fs_mount+0x73/0xa80 fs/9p/vfs_super.c:126
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1501
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1320/0x1fa0 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fc4c8e89209
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007fc4c9fd0168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc4c8f9bf60 RCX: 00007fc4c8e89209
RDX: 0000000020000140 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 00007fc4c8ee3161 R08: 0000000020000580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdb94b6f3f R14: 00007fc4c9fd0300 R15: 0000000000022000
</TASK>
Modules linked in:
CR2: fffffffffffffff8
---[ end trace 0000000000000000 ]---
RIP: 0010:swake_up_locked kernel/sched/swait.c:29 [inline]
RIP: 0010:swake_up_locked kernel/sched/swait.c:21 [inline]
RIP: 0010:complete+0x98/0x1f0 kernel/sched/completion.c:36
Code: e0 0f 84 f7 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 48 48 8d 7b f8 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 03 01 00 00 <48> 8b 7b f8 4c 8d 63 08 e8 8b 74 f8 ff 48 89 df e8 e3 79 a3 02 84
RSP: 0018:ffffc900030af978 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff815f0600
RDX: 1fffffffffffffff RSI: 0000000000000004 RDI: fffffffffffffff8
RBP: 0000000000000293 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000615f1d R11: 3e4b5341542f3c20 R12: ffff88806ef26cb8
R13: ffff88806ef26c78 R14: ffff8880205a6000 R15: ffff88806ef26c48
FS: 00007fc4c9fd0700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff8 CR3: 0000000078de1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 0f 84 f7 00 00 00 je 0xfd
6: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
d: fc ff df
10: 48 8b 5b 48 mov 0x48(%rbx),%rbx
14: 48 8d 7b f8 lea -0x8(%rbx),%rdi
18: 48 89 fa mov %rdi,%rdx
1b: 48 c1 ea 03 shr $0x3,%rdx
1f: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
23: 0f 85 03 01 00 00 jne 0x12c
* 29: 48 8b 7b f8 mov -0x8(%rbx),%rdi <-- trapping instruction
2d: 4c 8d 63 08 lea 0x8(%rbx),%r12
31: e8 8b 74 f8 ff callq 0xfff874c1
36: 48 89 df mov %rbx,%rdi
39: e8 e3 79 a3 02 callq 0x2a37a21
3e: 84 .byte 0x84


Tested on:

commit: cb71b93c Add linux-next specific files for 20220628
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=121acc4a080000
kernel config: https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb
dashboard link: https://syzkaller.appspot.com/bug?extid=5e28cdb7ebd0f2389ca4
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=109ffe72080000