general protection fault in __change_pid

[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=1471232eb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=6ff20097ac061f59b4b3
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ff200...@syzkaller.appspotmail.com

netlink: 'syz-executor.0': attribute type 10 has an invalid length.
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 27729 Comm: syz-executor.1 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__hlist_del include/linux/list.h:690 [inline]
RIP: 0010:hlist_del_rcu include/linux/rculist.h:457 [inline]
RIP: 0010:__change_pid+0x10a/0x2a0 kernel/pid.c:295
Code: 48 85 c0 48 89 03 48 89 04 24 74 2c e8 8f 84 23 00 48 8b 04 24 48 ba 00 00 00 00 00 fc ff df 48 8d 78 08 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 4a 01 00 00 48 89 58 08 e8 63 84 23 00 4c 89 e2
RSP: 0018:ffff88804a58fa30 EFLAGS: 00010002
RAX: 0077777056f027b0 RBX: ffff88809018b7a0 RCX: 000eeeee0ade04f7
RDX: dffffc0000000000 RSI: ffffffff813f00e1 RDI: 0077777056f027b8
RBP: ffff888000112500 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 1ffff1100acbd640 R12: ffff8880a9aa0468
R13: ffff88809018b780 R14: 0000000000000000 R15: ffff888000112530
FS: 000055555622c400(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a1ddce5160 CR3: 0000000043e07000 CR4: 00000000003426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__unhash_process kernel/exit.c:78 [inline]
__exit_signal kernel/exit.c:156 [inline]
release_task+0xd10/0x1480 kernel/exit.c:201
wait_task_zombie kernel/exit.c:1152 [inline]
wait_consider_task+0x2e1b/0x3910 kernel/exit.c:1379
do_wait_thread kernel/exit.c:1442 [inline]
do_wait+0x429/0x9c0 kernel/exit.c:1513
kernel_wait4+0x14c/0x260 kernel/exit.c:1655
__do_sys_wait4 kernel/exit.c:1667 [inline]
__se_sys_wait4+0x149/0x160 kernel/exit.c:1663
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f4ac0d54f87
Code: 89 7c 24 10 48 89 4c 24 18 e8 35 50 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 65 50 02 00 8b 44
RSP: 002b:00007ffe8f560520 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 0000000000000992 RCX: 00007f4ac0d54f87
RDX: 0000000040000001 RSI: 00007ffe8f5605ac RDI: 00000000ffffffff
RBP: 00007ffe8f5605ac R08: 0000000000000000 R09: 0000012eb2eeac6f
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 000000000011f379 R14: 0000000000000010 R15: 00007ffe8f560610
Modules linked in:
---[ end trace 72efdb072f27541a ]---
RIP: 0010:__hlist_del include/linux/list.h:690 [inline]
RIP: 0010:hlist_del_rcu include/linux/rculist.h:457 [inline]
RIP: 0010:__change_pid+0x10a/0x2a0 kernel/pid.c:295
Code: 48 85 c0 48 89 03 48 89 04 24 74 2c e8 8f 84 23 00 48 8b 04 24 48 ba 00 00 00 00 00 fc ff df 48 8d 78 08 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 4a 01 00 00 48 89 58 08 e8 63 84 23 00 4c 89 e2
RSP: 0018:ffff88804a58fa30 EFLAGS: 00010002
RAX: 0077777056f027b0 RBX: ffff88809018b7a0 RCX: 000eeeee0ade04f7
RDX: dffffc0000000000 RSI: ffffffff813f00e1 RDI: 0077777056f027b8
RBP: ffff888000112500 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 1ffff1100acbd640 R12: ffff8880a9aa0468
R13: ffff88809018b780 R14: 0000000000000000 R15: ffff888000112530
FS: 000055555622c400(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a1ddce5160 CR3: 0000000043e07000 CR4: 00000000003426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 48 85 c0 test %rax,%rax
3: 48 89 03 mov %rax,(%rbx)
6: 48 89 04 24 mov %rax,(%rsp)
a: 74 2c je 0x38
c: e8 8f 84 23 00 callq 0x2384a0
11: 48 8b 04 24 mov (%rsp),%rax
15: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx
1c: fc ff df
1f: 48 8d 78 08 lea 0x8(%rax),%rdi
23: 48 89 f9 mov %rdi,%rcx
26: 48 c1 e9 03 shr $0x3,%rcx
* 2a: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) <-- trapping instruction
2e: 0f 85 4a 01 00 00 jne 0x17e
34: 48 89 58 08 mov %rbx,0x8(%rax)
38: e8 63 84 23 00 callq 0x2384a0
3d: 4c 89 e2 mov %r12,%rdx


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.