WARNING in ceph_con_v2_try_read

Status: upstream: reported C repro on 2026/07/27 22:59
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+7bec276b8b8889ad21ab@syzkaller.appspotmail.com
First crash: 9d00h, last: 2d22h
Bug presence (1)
Date Name Commit Repro Result
2026/08/05 upstream (ToT) c21bb4193868 C [report] WARNING in ceph_con_v2_try_read
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in ceph_con_v2_try_read origin:upstream -1 syz, C 4 9d01h 9d15h 0/3 upstream: reported C repro on 2026/07/27 08:33
linux-6.1 WARNING in ceph_con_v2_try_read -1 syz, C 6 8d23h 9d16h 0/3 upstream: reported C repro on 2026/07/27 06:59
upstream WARNING in ceph_con_v2_try_read ceph prio:high -1 syz, C 41 2d17h 5d16h 0/29 upstream: reported C repro on 2026/07/31 07:09

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 178 at net/ceph/messenger_v2.c:3168 populate_in_iter net/ceph/messenger_v2.c:3168 [inline]
WARNING: CPU: 0 PID: 178 at net/ceph/messenger_v2.c:3168 ceph_con_v2_try_read+0x7d1d/0x7ea0 net/ceph/messenger_v2.c:3198
Modules linked in:
CPU: 0 PID: 178 Comm: kworker/0:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: ceph-msgr ceph_con_workfn
RIP: 0010:populate_in_iter net/ceph/messenger_v2.c:3168 [inline]
RIP: 0010:ceph_con_v2_try_read+0x7d1d/0x7ea0 net/ceph/messenger_v2.c:3198
Code: 41 5c 41 5d 41 5e 41 5f 5d c3 e8 9e 12 3a f7 48 c7 c7 40 23 e6 8b 44 89 f6 e8 9f e2 03 f7 0f 0b e9 57 ff ff ff e8 83 12 3a f7 <0f> 0b 41 bd c3 ff ff ff e9 4b ff ff ff e8 71 12 3a f7 0f 0b 41 bd
RSP: 0018:ffffc90002e97560 EFLAGS: 00010293
RAX: ffffffff8a4d5c9d RBX: ffff8880241186c8 RCX: ffff88801b3b3c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002e97b38 R08: 0000000000000004 R09: 0000000000000004
R10: ffff8880241186b4 R11: ffffed10048230d8 R12: fffff520005d2efc
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f235eb700 CR3: 0000000073623000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 ceph_con_workfn+0x1f1/0x1250 net/ceph/messenger.c:1574
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/03 01:23 linux-6.6.y a1153c0deb44 e611ffe1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 23:22 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 23:19 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 23:11 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 23:04 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 23:02 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 22:59 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
2026/07/27 22:58 linux-6.6.y c5596480c50e aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in ceph_con_v2_try_read
* Struck through repros no longer work on HEAD.