WARNING in __rds_conn_create (2)

Status: upstream: reported syz repro on 2026/10/16 02:45
Subsystems: rds
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+c3741bb338b5c6d6a4aa@syzkaller.appspotmail.com
First crash: 1d04h, last: 19h37m
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
b988ee26 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in __rds_conn_create (2) 2026/10/16 02:16 2026/10/16 02:16 2026/10/16 03:07 3f2522c6
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [rds?] WARNING in __rds_conn_create (2) 0 (1) 2026/10/16 02:45
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __rds_conn_create rds -1 1 455d 455d 0/29 closed as invalid on 2025/08/19 19:15

Sample crash report:
XFS (loop0): Quotacheck: Done.
------------[ cut here ]------------
raw_local_irq_restore() called with IRQs enabled
WARNING: kernel/locking/irqflag-debug.c:10 at warn_bogus_irq_restore+0xc/0x20 kernel/locking/irqflag-debug.c:10, CPU#0: syz.0.18/5745
Modules linked in:
CPU: 0 UID: 0 PID: 5745 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:warn_bogus_irq_restore+0xc/0x20 kernel/locking/irqflag-debug.c:10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 90 48 8d 3d c4 18 93 05 <67> 48 0f b9 3a 90 e9 99 04 03 00 cc cc cc cc cc cc cc cc cc 90 90
RSP: 0018:ffffc9000797f8c0 EFLAGS: 00010206
RAX: 0000000000000202 RBX: 0000000000000287 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff917dce80
RBP: ffffc9000797fa40 R08: ffffffff914a10e3 R09: 1ffffffff229421c
R10: dffffc0000000000 R11: fffffbfff229421d R12: ffffffff8b2acb15
R13: ffff888051146318 R14: ffffffff914a10e0 R15: 0000000000000287
FS:  00007f7afe2f56c0(0000) GS:ffff88808b0b4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7afd3ebc40 CR3: 000000004db87000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:210 [inline]
 _raw_spin_unlock_irqrestore+0x67/0x80 kernel/locking/spinlock.c:221
 spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
 __rds_conn_create+0x1de5/0x2290 net/rds/connection.c:364
 rds_conn_create_outgoing+0x43/0x60 net/rds/connection.c:394
 rds_sendmsg+0xfca/0x20e0 net/rds/send.c:1348
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
 __sock_sendmsg net/socket.c:815 [inline]
 __sys_sendto+0x408/0x5a0 net/socket.c:2281
 __do_sys_sendto net/socket.c:2288 [inline]
 __se_sys_sendto net/socket.c:2284 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2284
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7afd39e559
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:00007f7afe2f5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f7afd625fa0 RCX: 00007f7afd39e559
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f7afd4358b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7afd626038 R14: 00007f7afd625fa0 R15: 00007ffd156f7018
 </TASK>
----------------
Code disassembly (best guess):
   0:	cc                   	int3
   1:	cc                   	int3
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	cc                   	int3
   a:	cc                   	int3
   b:	cc                   	int3
   c:	cc                   	int3
   d:	cc                   	int3
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	f3 0f 1e fa          	endbr64
  22:	90                   	nop
  23:	48 8d 3d c4 18 93 05 	lea    0x59318c4(%rip),%rdi        # 0x59318ee
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	90                   	nop
  30:	e9 99 04 03 00       	jmp    0x304ce
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	cc                   	int3
  3c:	cc                   	int3
  3d:	cc                   	int3
  3e:	90                   	nop
  3f:	90                   	nop

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/15 08:51 upstream 0fcb05b72344 8fb0ae89 .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-snapshot-upstream-root WARNING in __rds_conn_create
2026/10/15 08:24 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d820e3baa404 8fb0ae89 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __rds_conn_create
2026/10/15 07:30 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d820e3baa404 8fb0ae89 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __rds_conn_create
2026/10/15 13:07 upstream 0fcb05b72344 8fb0ae89 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __rds_conn_create
2026/10/15 07:39 upstream 0fcb05b72344 8fb0ae89 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __rds_conn_create
2026/10/15 04:35 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d820e3baa404 8fb0ae89 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in __rds_conn_create
* Struck through repros no longer work on HEAD.