Subject: [syzbot] [kvm?] [net?] [virt?] BUG: sleeping function called from invalid context in vhost_get_avail_idx

From: syzbot <[email-masked]>
Date: Mon, 20 Apr 2026 15:09:24 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    8541d8f725c6 Merge tag 'mtd/for-7.1' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=136454ce580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7e54da1916e8d11f
dashboard link: https://syzkaller.appspot.com/bug?extid=6985cb8e543ea90ba8ee
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15d264ce580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=143ec1ba580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-8541d8f7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/22dfea2c37c2/vmlinux-8541d8f7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e2f93ad68fe3/bzImage-8541d8f7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

BUG: sleeping function called from invalid context at drivers/vhost/vhost.c:1527
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6110, name: vhost-6109
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
2 locks held by vhost-6109/6110:
 #0: ffff888055624cb0 (&vq->mutex/1){+.+.}-{4:4}, at: handle_tx+0x2d/0x160 drivers/vhost/net.c:971
 #1: ffff888055620248 (&vq->mutex){+.+.}-{4:4}, at: vhost_net_busy_poll+0x9c/0x730 drivers/vhost/net.c:554
Preemption disabled at:
[<ffffffff88f1a006>] vhost_net_busy_poll+0x1c6/0x730 drivers/vhost/net.c:563
CPU: 0 UID: 0 PID: 6110 Comm: vhost-6109 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
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 __might_resched.cold+0x1ec/0x232 kernel/sched/core.c:9162
 __might_fault+0x8b/0x140 mm/memory.c:7322
 vhost_get_avail_idx+0x31c/0x4f0 drivers/vhost/vhost.c:1527
 vhost_vq_avail_empty drivers/vhost/vhost.c:3206 [inline]
 vhost_vq_avail_empty+0xa9/0xe0 drivers/vhost/vhost.c:3199
 vhost_net_busy_poll+0x297/0x730 drivers/vhost/net.c:574
 vhost_net_tx_get_vq_desc drivers/vhost/net.c:610 [inline]
 get_tx_bufs.constprop.0+0x338/0x600 drivers/vhost/net.c:650
 handle_tx_copy+0x28c/0x12e0 drivers/vhost/net.c:778
 handle_tx+0x139/0x160 drivers/vhost/net.c:985
 vhost_run_work_list+0x183/0x220 drivers/vhost/vhost.c:454
 vhost_task_fn+0x156/0x430 kernel/vhost_task.c:49
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

---
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