From: syzbot ci <syzbot+ci28a5ab4f329a6a88@syzkaller.appspotmail.com>
To: ast@kernel.org, bjorn@kernel.org, bpf@vger.kernel.org,
daniel@iogearbox.net, davem@davemloft.net, edumazet@google.com,
hawk@kernel.org, john.fastabend@gmail.com,
jonathan.lemon@gmail.com, kerneljasonxing@gmail.com,
kernelxing@tencent.com, kuba@kernel.org,
maciej.fijalkowski@intel.com, magnus.karlsson@intel.com,
netdev@vger.kernel.org, pabeni@redhat.com, sdf@fomichev.me
Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com
Subject: [syzbot ci] Re: xsk: move cq_cached_prod_lock to avoid touching a cacheline in sending path
Date: Mon, 08 Dec 2025 23:51:36 -0800 [thread overview]
Message-ID: <6937d508.a70a0220.38f243.00c9.GAE@google.com> (raw)
In-Reply-To: <20251209031628.28429-1-kerneljasonxing@gmail.com>
syzbot ci has tested the following series
[v4] xsk: move cq_cached_prod_lock to avoid touching a cacheline in sending path
https://lore.kernel.org/all/20251209031628.28429-1-kerneljasonxing@gmail.com
* [PATCH RFC net-next v4] xsk: move cq_cached_prod_lock to avoid touching a cacheline in sending path
and found the following issue:
BUG: unable to handle kernel NULL pointer dereference in xp_create_and_assign_umem
Full report is available here:
https://ci.syzbot.org/series/d7e166a7-a880-4ea1-9707-8889afd4ebe8
***
BUG: unable to handle kernel NULL pointer dereference in xp_create_and_assign_umem
tree: net-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base: 0177f0f07886e54e12c6f18fa58f63e63ddd3c58
arch: amd64
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
config: https://ci.syzbot.org/builds/d327cc4b-7471-413b-b244-519c6d16d43b/config
C repro: https://ci.syzbot.org/findings/c8f7aeaf-0e2e-43dd-ae9c-ea2dd8db8d34/c_repro
syz repro: https://ci.syzbot.org/findings/c8f7aeaf-0e2e-43dd-ae9c-ea2dd8db8d34/syz_repro
UDPLite6: UDP-Lite is deprecated and scheduled to be removed in 2025, please contact the netdev mailing list
BUG: kernel NULL pointer dereference, address: 0000000000000058
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 80000001b2496067 P4D 80000001b2496067 PUD 0
Oops: Oops: 0002 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 5973 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:lockdep_init_map_type+0x1e/0x380 kernel/locking/lockdep.c:4944
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 56 53 48 83 ec 10 89 cd 48 89 fb 65 48 8b 05 67 af d1 10 48 89 44 24 08 <48> c7 47 10 00 00 00 00 48 c7 47 08 00 00 00 00 8b 05 8c f2 dc 17
RSP: 0018:ffffc90003c07bb8 EFLAGS: 00010286
RAX: ec490cf5c114aa00 RBX: 0000000000000048 RCX: 0000000000000000
RDX: ffffffff99d16120 RSI: ffffffff8c92a180 RDI: 0000000000000048
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: ffffed102e5d7800 R11: fffffbfff1efa3cf R12: dffffc0000000000
R13: ffff8881bdeb3000 R14: ffffffff99d16120 R15: ffffffff8c92a180
FS: 00005555729bd500(0000) GS:ffff8882a9f31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000058 CR3: 0000000172faa000 CR4: 00000000000006f0
Call Trace:
<TASK>
lockdep_init_map_waits include/linux/lockdep.h:135 [inline]
lockdep_init_map_wait include/linux/lockdep.h:142 [inline]
__raw_spin_lock_init+0x45/0x100 kernel/locking/spinlock_debug.c:25
xp_create_and_assign_umem+0x648/0xd40 net/xdp/xsk_buff_pool.c:94
xsk_bind+0x95a/0xf90 net/xdp/xsk.c:1355
__sys_bind_socket net/socket.c:1874 [inline]
__sys_bind+0x2c6/0x3e0 net/socket.c:1905
__do_sys_bind net/socket.c:1910 [inline]
__se_sys_bind net/socket.c:1908 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1908
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f591eb8f7c9
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:00007ffce6fcef48 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00007f591ede5fa0 RCX: 00007f591eb8f7c9
RDX: 0000000000000010 RSI: 0000200000000240 RDI: 0000000000000003
RBP: 00007f591ebf297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f591ede5fa0 R14: 00007f591ede5fa0 R15: 0000000000000003
</TASK>
Modules linked in:
CR2: 0000000000000058
---[ end trace 0000000000000000 ]---
RIP: 0010:lockdep_init_map_type+0x1e/0x380 kernel/locking/lockdep.c:4944
Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 56 53 48 83 ec 10 89 cd 48 89 fb 65 48 8b 05 67 af d1 10 48 89 44 24 08 <48> c7 47 10 00 00 00 00 48 c7 47 08 00 00 00 00 8b 05 8c f2 dc 17
RSP: 0018:ffffc90003c07bb8 EFLAGS: 00010286
RAX: ec490cf5c114aa00 RBX: 0000000000000048 RCX: 0000000000000000
RDX: ffffffff99d16120 RSI: ffffffff8c92a180 RDI: 0000000000000048
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000
R10: ffffed102e5d7800 R11: fffffbfff1efa3cf R12: dffffc0000000000
R13: ffff8881bdeb3000 R14: ffffffff99d16120 R15: ffffffff8c92a180
FS: 00005555729bd500(0000) GS:ffff8882a9f31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000058 CR3: 0000000172faa000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 90 nop
3: 90 nop
4: 90 nop
5: 90 nop
6: 90 nop
7: 90 nop
8: 90 nop
9: 90 nop
a: 90 nop
b: 90 nop
c: f3 0f 1e fa endbr64
10: 55 push %rbp
11: 41 56 push %r14
13: 53 push %rbx
14: 48 83 ec 10 sub $0x10,%rsp
18: 89 cd mov %ecx,%ebp
1a: 48 89 fb mov %rdi,%rbx
1d: 65 48 8b 05 67 af d1 mov %gs:0x10d1af67(%rip),%rax # 0x10d1af8c
24: 10
25: 48 89 44 24 08 mov %rax,0x8(%rsp)
* 2a: 48 c7 47 10 00 00 00 movq $0x0,0x10(%rdi) <-- trapping instruction
31: 00
32: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi)
39: 00
3a: 8b 05 8c f2 dc 17 mov 0x17dcf28c(%rip),%eax # 0x17dcf2cc
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
next prev parent reply other threads:[~2025-12-09 7:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-09 3:16 [PATCH RFC net-next v4] xsk: move cq_cached_prod_lock to avoid touching a cacheline in sending path Jason Xing
2025-12-09 7:51 ` syzbot ci [this message]
2025-12-09 12:12 ` [syzbot ci] " Jason Xing
2025-12-09 14:15 ` Jason Xing
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