[syzbot] [ceph?] WARNING in ceph_con_v2_try_read

[syzbot <syzbot+87c7c2d63c44e41c77a3@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    4235cb24ec1e Merge tag 'vfs-7.2-rc5.fixes' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129ba7b1580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4e38b15c29e6a1d9
dashboard link: https://syzkaller.appspot.com/bug?extid=87c7c2d63c44e41c77a3
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16d96499580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12eaf2ea580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/906b09e16f16/disk-4235cb24.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2cb120bc3818/vmlinux-4235cb24.xz
kernel image: https://storage.googleapis.com/syzbot-assets/880615d1b5d5/bzImage-4235cb24.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87c7c2d63c44e41c77a3@syzkaller.appspotmail.com

------------[ cut here ]------------
!iov_iter_count(&con->v2.in_iter)
WARNING: net/ceph/messenger_v2.c:3129 at populate_in_iter net/ceph/messenger_v2.c:3129 [inline], CPU#0: kworker/0:2/188
WARNING: net/ceph/messenger_v2.c:3129 at ceph_con_v2_try_read+0x6634/0x6810 net/ceph/messenger_v2.c:3159, CPU#0: kworker/0:2/188
Modules linked in:
CPU: 0 UID: 0 PID: 188 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: ceph-msgr ceph_con_workfn
RIP: 0010:populate_in_iter net/ceph/messenger_v2.c:3129 [inline]
RIP: 0010:ceph_con_v2_try_read+0x6634/0x6810 net/ceph/messenger_v2.c:3159
Code: 8d 3d 70 31 d5 04 43 0f b6 04 3e 84 c0 48 8b 54 24 38 0f 85 85 00 00 00 8b 32 67 48 0f b9 3a e9 40 ff ff ff e8 3d cd 31 f6 90 <0f> 0b 90 41 bd c3 ff ff ff e9 32 ff ff ff e8 29 cd 31 f6 90 0f 0b
RSP: 0018:ffffc90002f574a0 EFLAGS: 00010293
RAX: ffffffff8b9536c3 RBX: 0000000000000000 RCX: ffff888020b05d00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002f57a78 R08: ffff888033ca86a7 R09: ffff888033ca869b
R10: dffffc0000000000 R11: ffffed10067950d5 R12: fffff520005eaee4
R13: 0000000000000000 R14: 0000000000000010 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888124f4e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7c5aa0fff8 CR3: 00000000251ca000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 ceph_con_workfn+0x1f5/0x14a0 net/ceph/messenger.c:1575
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


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