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

From: syzbot <[email-masked]>
Date: Mon, 08 Dec 2025 03:21:24 -0800

Hello,

syzbot found the following issue on:

HEAD commit:    559e608c4655 Merge tag 'ntfs3_for_6.19' of https://github...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164fdcc2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=74c2ec4187efdce
dashboard link: https://syzkaller.appspot.com/bug?extid=b1546ad4a95331b2101e
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1446301a580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=112c3f42580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7d28798cb263/disk-559e608c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/239e800627b8/vmlinux-559e608c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e89da2cc9887/bzImage-559e608c.xz

The issue was bisected to:

commit 0db4941d9dae159d887e7e2eac7e54e60c3aac87
Author: Fushuai Wang <[email-masked]>
Date:   Tue Oct 7 07:40:11 2025 +0000

    bpf: Use rcu_read_lock_dont_migrate in bpf_sk_storage.c

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10cd3c1a580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=12cd3c1a580000
console output: https://syzkaller.appspot.com/x/log.txt?x=14cd3c1a580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]
Fixes: 0db4941d9dae ("bpf: Use rcu_read_lock_dont_migrate in bpf_sk_storage.c")

BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128, name: syz.3.73
preempt_count: 2, expected: 0
RCU nest depth: 1, expected: 1
3 locks held by syz.3.73/6128:
 #0: ffff8880493da398 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1700 [inline]
 #0: ffff8880493da398 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: vsock_connect+0x152/0xd40 net/vmw_vsock/af_vsock.c:1546
 #1: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #1: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #1: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2074 [inline]
 #1: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run9+0x1ec/0x510 kernel/trace/bpf_trace.c:2123
 #2: ffff8880b893fd48 (&s->lock_key#14){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
 #2: ffff8880b893fd48 (&s->lock_key#14){+.+.}-{3:3}, at: ___slab_alloc+0x12f/0x1400 mm/slub.c:4516
Preemption disabled at:
[<ffffffff82179f5a>] class_preempt_constructor include/linux/preempt.h:468 [inline]
[<ffffffff82179f5a>] __migrate_enable include/linux/sched.h:2378 [inline]
[<ffffffff82179f5a>] migrate_enable include/linux/sched.h:2429 [inline]
[<ffffffff82179f5a>] __slab_alloc+0xea/0x1f0 mm/slub.c:4777
CPU: 1 UID: 0 PID: 6128 Comm: syz.3.73 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 __might_resched+0x44b/0x5d0 kernel/sched/core.c:8830
 __rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline]
 rt_spin_lock+0xc7/0x3e0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 ___slab_alloc+0x12f/0x1400 mm/slub.c:4516
 __slab_alloc+0xc6/0x1f0 mm/slub.c:4774
 __slab_alloc_node mm/slub.c:4850 [inline]
 kmalloc_nolock_noprof+0x1be/0x440 mm/slub.c:5729
 bpf_stream_elem_alloc kernel/bpf/stream.c:33 [inline]
 __bpf_stream_push_str+0xa8/0x2b0 kernel/bpf/stream.c:50
 bpf_stream_stage_printk+0x14e/0x1c0 kernel/bpf/stream.c:306
 bpf_prog_report_may_goto_violation+0xc4/0x190 kernel/bpf/core.c:3203
 bpf_check_timed_may_goto+0xaa/0xb0 kernel/bpf/core.c:3221
 arch_bpf_timed_may_goto+0x21/0x40 arch/x86/net/bpf_timed_may_goto.S:40
 bpf_prog_262a74d054ad2993+0x53/0x5f
 bpf_dispatcher_nop_func include/linux/bpf.h:1376 [inline]
 __bpf_prog_run include/linux/filter.h:723 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run9+0x2de/0x510 kernel/trace/bpf_trace.c:2123
 __bpf_trace_virtio_transport_alloc_pkt+0x2d7/0x340 include/trace/events/vsock_virtio_transport_common.h:39
 __do_trace_virtio_transport_alloc_pkt include/trace/events/vsock_virtio_transport_common.h:39 [inline]
 trace_virtio_transport_alloc_pkt include/trace/events/vsock_virtio_transport_common.h:39 [inline]
 virtio_transport_alloc_skb+0x10af/0x1110 net/vmw_vsock/virtio_transport_common.c:311
 virtio_transport_send_pkt_info+0x694/0x10b0 net/vmw_vsock/virtio_transport_common.c:390
 virtio_transport_connect+0xa7/0x100 net/vmw_vsock/virtio_transport_common.c:1072
 vsock_connect+0xaca/0xd40 net/vmw_vsock/af_vsock.c:1611
 __sys_connect_file net/socket.c:2080 [inline]
 __sys_connect+0x323/0x450 net/socket.c:2099
 __do_sys_connect net/socket.c:2105 [inline]
 __se_sys_connect net/socket.c:2102 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2102
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c4d91f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd8ed26ac8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007f0c4db75fa0 RCX: 00007f0c4d91f749
RDX: 0000000000000010 RSI: 0000200000000080 RDI: 0000000000000003
RBP: 00007f0c4d9a3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c4db75fa0 R14: 00007f0c4db75fa0 R15: 0000000000000003
 </TASK>

---
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