[syzbot ci] Re: net/rds: RDS-TCP reconnect and fanout improvements

[syzbot ci]

syzbot ci has tested the following series

[v1] net/rds: RDS-TCP reconnect and fanout improvements
https://lore.kernel.org/all/20260206022419.1...@kernel.org
* [PATCH net-next v1 1/3] net/rds: Delegate fan-out to a background worker
* [PATCH net-next v1 2/3] net/rds: Use proper peer port number even when not connected
* [PATCH net-next v1 3/3] net/rds: rds_sendmsg should not discard payload_len

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

Full report is available here:
https://ci.syzbot.org/series/1a5ef180-c02c-401d-9df7-670b18570a55

***

BUG: sleeping function called from invalid context in rds_tcp_conn_free

tree: net-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base: 7a4cd71fa4514cd85df39b3cf99da8142660cdcd
arch: amd64
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config: https://ci.syzbot.org/builds/77f47047-43cb-4c25-b0b6-73b8746cea2a/config
syz repro: https://ci.syzbot.org/findings/49698f1e-4f36-4446-9dd1-c409366e6296/syz_repro

BUG: sleeping function called from invalid context at kernel/workqueue.c:4390
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 6005, name: syz.2.19
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 0
2 locks held by syz.2.19/6005:
#0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e35a360 (rcu_read_lock){....}-{1:3}, at: __rds_conn_create+0x2e4/0x22d0 net/rds/connection.c:177
#1: ffffffff8fa00a98 (rds_conn_lock){....}-{3:3}, at: __rds_conn_create+0x18e2/0x22d0 net/rds/connection.c:304
irq event stamp: 752
hardirqs last enabled at (751): [<ffffffff8b7cc843>] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:159 [inline]
hardirqs last enabled at (751): [<ffffffff8b7cc843>] _raw_spin_unlock_irq+0x23/0x50 kernel/locking/spinlock.c:202
hardirqs last disabled at (752): [<ffffffff8b7cc61a>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
hardirqs last disabled at (752): [<ffffffff8b7cc61a>] _raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:162
softirqs last enabled at (32): [<ffffffff8ac0cd59>] rds_sendmsg+0x7b9/0x2150 net/rds/send.c:1266
softirqs last disabled at (30): [<ffffffff89463a1f>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (30): [<ffffffff89463a1f>] release_sock+0x2f/0x1f0 net/core/sock.c:3793
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 UID: 0 PID: 6005 Comm: syz.2.19 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+0xe8/0x150 lib/dump_stack.c:120
__might_resched+0x378/0x4d0 kernel/sched/core.c:8829
__cancel_work_sync+0x6d/0x110 kernel/workqueue.c:4390
rds_tcp_conn_free+0x2c/0x170 net/rds/tcp.c:361
__rds_conn_create+0x1bfb/0x22d0 net/rds/connection.c:334
rds_conn_create_outgoing+0x43/0x60 net/rds/connection.c:377
rds_sendmsg+0xff5/0x2150 net/rds/send.c:1321
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x4d7/0x810 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5b6bf9acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5b6cd8b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5b6c216090 RCX: 00007f5b6bf9acb9
RDX: 0000000000000000 RSI: 0000200000000480 RDI: 0000000000000004
RBP: 00007f5b6c008bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5b6c216128 R14: 00007f5b6c216090 R15: 00007ffc17760058
</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: syz...@syzkaller.appspotmail.com

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