syzbot
WARNING in f_midi_free
Status:
upstream: reported on 2026/08/01 00:02
Subsystems:
usb
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+d5fa3d224505c8610702@syzkaller.appspotmail.com
Fix commit:
7e07d3e4c389
usb: gadget: f_midi: initialize work in f_midi_alloc()
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root]
First crash: 54d, last: 17d
Sample crash report:
------------[ cut here ]------------
!work->func
WARNING: kernel/workqueue.c:4409 at __flush_work+0xc68/0xd70 kernel/workqueue.c:4409, CPU#0: syz.2.2761/18561
Modules linked in:
CPU: 0 UID: 0 PID: 18561 Comm: syz.2.2761 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__flush_work+0xc68/0xd70 kernel/workqueue.c:4409
Code: 6b 8b e8 8b 7d 13 00 48 c7 c7 c0 3a 1c 8e 48 89 de e9 49 ff ff ff e8 f7 f5 37 00 90 0f 0b 90 e9 45 ff ff ff e8 e9 f5 37 00 90 <0f> 0b 90 31 c0 49 bd f8 f8 f8 f8 f8 f8 f8 f8 e9 2d ff ff ff e8 cf
RSP: 0018:ffffc9000576fa20 EFLAGS: 00010287
RAX: ffffffff818e83d7 RBX: ffff88803727f1b0 RCX: 0000000000080000
RDX: ffffc90007ab9000 RSI: 0000000000000a4f RDI: 0000000000000a50
RBP: ffffc9000576fbd0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f63bb0 R12: dffffc0000000000
R13: 1ffff11006e4fe36 R14: 1ffff92000aedf4c R15: ffff88803727f198
FS: 00007f48308b66c0(0000) GS:ffff888125bd6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4830874d58 CR3: 0000000032594000 CR4: 00000000003526f0
Call Trace:
<TASK>
__cancel_work_sync+0xbf/0x110 kernel/workqueue.c:4568
f_midi_free+0xac/0x1f0 drivers/usb/gadget/function/f_midi.c:1312
config_usb_cfg_unlink+0x236/0x260 drivers/usb/gadget/configfs.c:508
configfs_symlink+0xde9/0x1030 fs/configfs/symlink.c:202
vfs_symlink+0x18b/0x330 fs/namei.c:5794
filename_symlinkat+0x1cd/0x420 fs/namei.c:5819
__do_sys_symlinkat fs/namei.c:5839 [inline]
__se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5834
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f483265e159
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:00007f48308b6028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f48328e5fa0 RCX: 00007f483265e159
RDX: 0000200000000340 RSI: ffffffffffffff9c RDI: 0000200000000100
RBP: 00007f48326f5024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f48328e6038 R14: 00007f48328e5fa0 R15: 00007ffc67a153d8
</TASK>
Struck through repros no longer work on HEAD.