[syzbot] [block?] WARNING in ublk_ch_batch_io_uring_cmd

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ab9de95c9cf9 Merge tag 'rust-7.2-2' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=120f22ae580000
kernel config: https://syzkaller.appspot.com/x/.config?x=86ba763b42fa66a
dashboard link: https://syzkaller.appspot.com/bug?extid=1a67ee1aa79484801ec6
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c16df342a923/disk-ab9de95c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ddf00a828178/vmlinux-ab9de95c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f468c716a7be/bzImage-ab9de95c.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1a67ee...@syzkaller.appspotmail.com

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ret
WARNING: drivers/block/ublk_drv.c:3683 at ublk_batch_revert_prep_cmd drivers/block/ublk_drv.c:3683 [inline], CPU#1: syz.3.517/8158
WARNING: drivers/block/ublk_drv.c:3683 at ublk_handle_batch_prep_cmd drivers/block/ublk_drv.c:3732 [inline], CPU#1: syz.3.517/8158
WARNING: drivers/block/ublk_drv.c:3683 at ublk_ch_batch_io_uring_cmd+0x1626/0x1830 drivers/block/ublk_drv.c:3999, CPU#1: syz.3.517/8158
Modules linked in:
CPU: 1 UID: 0 PID: 8158 Comm: syz.3.517 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:ublk_batch_revert_prep_cmd drivers/block/ublk_drv.c:3683 [inline]
RIP: 0010:ublk_handle_batch_prep_cmd drivers/block/ublk_drv.c:3732 [inline]
RIP: 0010:ublk_ch_batch_io_uring_cmd+0x1626/0x1830 drivers/block/ublk_drv.c:3999
Code: ff e8 2e c4 96 05 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c f8 ec ff ff 4c 89 ff e8 05 5f 17 fc e9 eb ec ff ff e8 bb d0 a9 fb 90 <0f> 0b 90 e9 a9 fe ff ff 44 89 f1 80 e1 07 fe c1 38 c1 0f 8c bb ed
RSP: 0018:ffffc90004387480 EFLAGS: 00010283
RAX: ffffffff861c5fe5 RBX: ffff888054070090 RCX: 0000000000080000
RDX: ffffc9000db0b000 RSI: 0000000000003aa6 RDI: 0000000000003aa7
RBP: ffffc90004387aa0 R08: ffffc900043877e0 R09: 1ffff92000870efc
R10: dffffc0000000000 R11: fffff52000870efd R12: 00000000ffffffea
R13: ffff8880260c2770 R14: 00000000ffffffea R15: 0000000000000020
FS: 00007fdc0093f6c0(0000) GS:ffff888125327000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2b3d7e8158 CR3: 0000000053938000 CR4: 0000000000350ef0
Call Trace:
<TASK>
io_uring_cmd+0x2e6/0x8b0 io_uring/uring_cmd.c:271
__io_issue_sqe+0x188/0x4d0 io_uring/io_uring.c:1395
io_issue_sqe+0x16d/0x1020 io_uring/io_uring.c:1418
io_queue_sqe io_uring/io_uring.c:1649 [inline]
io_submit_sqe io_uring/io_uring.c:1934 [inline]
io_submit_sqes+0xd26/0x2310 io_uring/io_uring.c:2057
__do_sys_io_uring_enter io_uring/io_uring.c:2646 [inline]
__se_sys_io_uring_enter+0x35b/0x1bb0 io_uring/io_uring.c:2595
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbff99ce59
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:00007fdc0093ef38 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000200000001f40 RCX: 00007fdbff99ce59
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000007
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000b40
R13: 0000200000000b48 R14: 0000000000000104 R15: 0000000000000000
</TASK>


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