Message-ID: <6915e239.a70a0220.3124cb.0029.GAE@google.com>
Date: Thu, 13 Nov 2025 05:50:49 -0800
From: syzbot ci <syzbot+ci9bdcb0a5ada952db@...kaller.appspotmail.com>
To: coreteam@...filter.org, davem@...emloft.net, edumazet@...gle.com, 
	fw@...len.de, horms@...nel.org, kadlec@...filter.org, kuba@...nel.org, 
	linux-kernel@...r.kernel.org, netdev@...r.kernel.org, 
	netfilter-devel@...r.kernel.org, pabeni@...hat.com, pablo@...filter.org, 
	phil@....cc, scott.k.mitch1@...il.com, scott_mitchell@...le.com
Cc: syzbot@...ts.linux.dev, syzkaller-bugs@...glegroups.com
Subject: [syzbot ci] Re: netfilter: nfnetlink_queue: optimize verdict lookup
 with hash table

syzbot ci has tested the following series

[v2] netfilter: nfnetlink_queue: optimize verdict lookup with hash table
https://lore.kernel.org/all/20251113092606.91406-1-scott_mitchell@apple.com
* [PATCH v2] netfilter: nfnetlink_queue: optimize verdict lookup with hash table

and found the following issue:
BUG: sleeping function called from invalid context in instance_create

Full report is available here:
https://ci.syzbot.org/series/001a6a6c-7e1b-46e8-995d-5b6d650af320

***

BUG: sleeping function called from invalid context in instance_create

tree:      nf-next
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf-next.git
base:      0d0eb186421d0886ac466008235f6d9eedaf918e
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/69a4254b-f4aa-45a7-a4bd-2d23940887f3/config
C repro:   https://ci.syzbot.org/findings/8074062c-0aee-4734-a3d1-587b80676bf1/c_repro
syz repro: https://ci.syzbot.org/findings/8074062c-0aee-4734-a3d1-587b80676bf1/syz_repro

netlink: 'syz.0.17': attribute type 6 has an invalid length.
BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:321
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5968, name: syz.0.17
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 0
3 locks held by syz.0.17/5968:
 #0: ffffffff99cc1c30 (nfnl_subsys_queue){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
 #0: ffffffff99cc1c30 (nfnl_subsys_queue){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
 #1: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #1: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #1: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: nfqnl_recv_config+0x222/0xf90 net/netfilter/nfnetlink_queue.c:1653
 #2: ffff888112297d18 (&q->instances_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #2: ffff888112297d18 (&q->instances_lock){+.+.}-{3:3}, at: instance_create+0x121/0x740 net/netfilter/nfnetlink_queue.c:206
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 1 UID: 0 PID: 5968 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
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 __might_resched+0x495/0x610 kernel/sched/core.c:8927
 might_alloc include/linux/sched/mm.h:321 [inline]
 slab_pre_alloc_hook mm/slub.c:4913 [inline]
 slab_alloc_node mm/slub.c:5248 [inline]
 __do_kmalloc_node mm/slub.c:5633 [inline]
 __kvmalloc_node_noprof+0x149/0x910 mm/slub.c:7089
 kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline]
 instance_create+0x203/0x740 net/netfilter/nfnetlink_queue.c:218
 nfqnl_recv_config+0x660/0xf90 net/netfilter/nfnetlink_queue.c:1667
 nfnetlink_rcv_msg+0xb4d/0x1130 net/netfilter/nfnetlink.c:302
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 nfnetlink_rcv+0x282/0x2590 net/netfilter/nfnetlink.c:669
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 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: 0033:0x7f7a65f8f6c9
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:00007ffde4361588 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7a661e5fa0 RCX: 00007f7a65f8f6c9
RDX: 0000000000008010 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f7a66011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a661e5fa0 R14: 00007f7a661e5fa0 R15: 0000000000000003
 </TASK>


***

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@...kaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@...glegroups.com.

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