[moderation] [fs?] general protection fault in send_sigurg

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 033a4691702c Add linux-next specific files for 20240813
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=156e1191980000
kernel config: https://syzkaller.appspot.com/x/.config?x=61ba6f3b22ee5467
dashboard link: https://syzkaller.appspot.com/bug?extid=db3aa82673ee6c6ab1c2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [alex....@gmail.com bra...@kernel.org chuck...@oracle.com ja...@suse.cz jla...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8ae4f1208eb6/disk-033a4691.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4d2a189491e1/vmlinux-033a4691.xz
kernel image: https://storage.googleapis.com/syzbot-assets/af4d4ce1cdec/bzImage-033a4691.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+db3aa8...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 UID: 0 PID: 5411 Comm: syz.3.38 Not tainted 6.11.0-rc3-next-20240813-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:__lock_acquire+0x69/0x2040 kernel/locking/lockdep.c:5010
Code: b6 04 30 84 c0 0f 85 87 16 00 00 45 31 f6 83 3d 28 c5 a8 0e 00 0f 84 ac 13 00 00 89 54 24 54 89 5c 24 68 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ff e8 c9 2c 8c 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90008b87090 EFLAGS: 00010002
RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff2030fbe R12: ffff8880728c1e00
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000020
FS: 00007ff848ce86c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002027f000 CR3: 000000007ad4e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5762
__raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
_raw_read_lock_irqsave+0xdd/0x130 kernel/locking/spinlock.c:236
send_sigurg+0x5a/0x3d0 fs/fcntl.c:945
sk_send_sigurg+0x6e/0x2f0 net/core/sock.c:3432
tcp_check_urg+0x207/0x740 net/ipv4/tcp_input.c:5835
tcp_urg+0x15c/0x450 net/ipv4/tcp_input.c:5876
tcp_rcv_established+0xfaf/0x2020 net/ipv4/tcp_input.c:6231
tcp_v6_do_rcv+0x5c8/0x13a0 net/ipv6/tcp_ipv6.c:1640
sk_backlog_rcv include/net/sock.h:1111 [inline]
__release_sock+0x1c8/0x350 net/core/sock.c:3004
release_sock+0x61/0x1f0 net/core/sock.c:3558
sk_stream_wait_memory+0x762/0xfa0 net/core/stream.c:145
tcp_sendmsg_locked+0x1471/0x4e10 net/ipv4/tcp.c:1312
tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1354
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0xef/0x270 net/socket.c:745
__sys_sendto+0x3a4/0x4f0 net/socket.c:2204
__do_sys_sendto net/socket.c:2216 [inline]
__se_sys_sendto net/socket.c:2212 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2212
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff847f799f9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff848ce8038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ff848115f80 RCX: 00007ff847f799f9
RDX: 00000000d0d0c2ac RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00007ff847fe78ee R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff848115f80 R15: 00007ffc45b5bca8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x69/0x2040 kernel/locking/lockdep.c:5010
Code: b6 04 30 84 c0 0f 85 87 16 00 00 45 31 f6 83 3d 28 c5 a8 0e 00 0f 84 ac 13 00 00 89 54 24 54 89 5c 24 68 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ff e8 c9 2c 8c 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90008b87090 EFLAGS: 00010002
RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff2030fbe R12: ffff8880728c1e00
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000020
FS: 00007ff848ce86c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002027f000 CR3: 000000007ad4e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: b6 04 mov $0x4,%dh
2: 30 84 c0 0f 85 87 16 xor %al,0x1687850f(%rax,%rax,8)
9: 00 00 add %al,(%rax)
b: 45 31 f6 xor %r14d,%r14d
e: 83 3d 28 c5 a8 0e 00 cmpl $0x0,0xea8c528(%rip) # 0xea8c53d
15: 0f 84 ac 13 00 00 je 0x13c7
1b: 89 54 24 54 mov %edx,0x54(%rsp)
1f: 89 5c 24 68 mov %ebx,0x68(%rsp)
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 30 00 cmpb $0x0,(%rax,%rsi,1) <-- trapping instruction
2e: 74 12 je 0x42
30: 4c 89 ff mov %r15,%rdi
33: e8 c9 2c 8c 00 call 0x8c2d01
38: 48 rex.W
39: be 00 00 00 00 mov $0x0,%esi
3e: 00 fc add %bh,%ah


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

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