KASAN: invalid-free in f_uac1_opts_c_srate_store

Status: upstream: reported C repro on 2026/08/02 03:46
Subsystems: usb
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+2532c7901f590afd0c3a@syzkaller.appspotmail.com
First crash: 98d, last: 67d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
e606b792 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: invalid-free in f_uac1_opts_c_srate_store 2026/07/31 01:30 2026/07/31 01:30 2026/07/31 03:32 aaffb173
▶ ▼ Discussions (4)
Title Replies (including bot) Last reply
[PATCH 0/2] usb: gadget: f_uac1/f_uac2: fix invalid-free in srate configfs store 2 (2) 2026/08/04 17:43
[PATCH 2/2] usb: gadget: f_uac1: fix invalid-free in srate configfs store 1 (1) 2026/08/04 17:43
[PATCH] usb: gadget: f_uac1/f_uac2: fix invalid-free and memory leak in sampling rate store 1 (1) 2026/08/02 16:28
[syzbot] [usb?] KASAN: invalid-free in f_uac1_opts_c_srate_store 0 (3) 2026/08/02 13:27
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 KASAN: invalid-free in f_uac1_opts_c_srate_store origin:lts 24 syz, C 6 65d 100d 0/1 premoderation: reported C repro on 2026/07/27 01:32
android-6-1 KASAN: invalid-free in f_uac1_opts_c_srate_store origin:lts 24 syz, C 1 23d 55d 0/2 upstream: reported C repro on 2026/09/10 09:00
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/10/24 14:21 19m retest repro upstream no crash job log log
2026/08/15 14:02 13m retest repro upstream report job log log
2026/08/02 13:27 25m subasris1210@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-linus OK log
2026/08/02 12:54 6m subasris1210@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 5d5fd841c34649f1b09220fe58e59dffd61c447d error

Sample crash report:
==================================================================
BUG: KASAN: invalid-free in f_uac1_opts_c_srate_store+0x225/0x2b0 drivers/usb/gadget/function/f_uac1.c:1666
Free of addr ffff888043c73420 by task syz.0.0/5318

CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 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_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557
 check_slab_allocation mm/kasan/common.c:-1 [inline]
 __kasan_slab_pre_free+0x104/0x120 mm/kasan/common.c:261
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2623 [inline]
 slab_free mm/slub.c:6372 [inline]
 kfree+0x173/0x640 mm/slub.c:6687
 f_uac1_opts_c_srate_store+0x225/0x2b0 drivers/usb/gadget/function/f_uac1.c:1666
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 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: 0033:0x7f9ec035e98e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007f9ec11d7d08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9ec11d86c0 RCX: 00007f9ec035e98e
RDX: 0000000000000027 RSI: 00007f9ec11d7eb0 RDI: 0000000000000002
RBP: 00007f9ec11d7eb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000027
R13: 00007f9ec05f27a0 R14: 00007f9ec05e94a0 R15: 0000000000000001
 </TASK>

Allocated by task 5318:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5337 [inline]
 __kmalloc_node_track_caller_noprof+0x4c7/0x740 mm/slub.c:5466
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x42/0x100 mm/util.c:84
 f_uac1_opts_c_srate_store+0x11f/0x2b0 drivers/usb/gadget/function/f_uac1.c:1666
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x337/0x430 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 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

The buggy address belongs to the object at ffff888043c73400
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 32 bytes inside of
 40-byte region [ffff888043c73400, ffff888043c73428)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43c73
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801b0418c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 112, tgid 112 (kworker/0:2), ts 85191553992
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3267 [inline]
 allocate_slab+0x7c/0x5e0 mm/slub.c:3382
 new_slab mm/slub.c:3428 [inline]
 refill_objects+0x2d5/0x350 mm/slub.c:7305
 refill_sheaf mm/slub.c:2805 [inline]
 __pcs_replace_empty_main+0x2c3/0x6b0 mm/slub.c:4677
 alloc_from_pcs mm/slub.c:4775 [inline]
 slab_alloc_node mm/slub.c:4907 [inline]
 __do_kmalloc_node mm/slub.c:5336 [inline]
 __kmalloc_noprof+0x489/0x720 mm/slub.c:5362
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 alloc_indirect_split drivers/virtio/virtio_ring.c:610 [inline]
 virtqueue_add_split+0x1a7/0x2120 drivers/virtio/virtio_ring.c:685
 virtqueue_add+0x100/0x2960 drivers/virtio/virtio_ring.c:2839
 virtqueue_add_sgs+0x17f/0x1a0 drivers/virtio/virtio_ring.c:2878
 virtio_gpu_queue_ctrl_sgs drivers/gpu/drm/virtio/virtgpu_vq.c:415 [inline]
 virtio_gpu_queue_fenced_ctrl_buffer+0xae7/0x10c0 drivers/gpu/drm/virtio/virtgpu_vq.c:500
 virtio_gpu_resource_flush drivers/gpu/drm/virtio/virtgpu_plane.c:229 [inline]
 virtio_gpu_primary_plane_update+0xc43/0x1310 drivers/gpu/drm/virtio/virtgpu_plane.c:304
 drm_atomic_helper_commit_planes+0x626/0xea0 drivers/gpu/drm/drm_atomic_helper.c:3038
 drm_atomic_helper_commit_tail+0x60/0x510 drivers/gpu/drm/drm_atomic_helper.c:1989
 commit_tail+0x2b1/0x3c0 drivers/gpu/drm/drm_atomic_helper.c:2074
 drm_atomic_helper_commit+0xa77/0xb10 drivers/gpu/drm/drm_atomic_helper.c:2312
page last free pid 5270 tgid 5270 ts 78910959126 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
 tlb_batch_list_free mm/mmu_gather.c:161 [inline]
 tlb_finish_mmu+0x13e/0x220 mm/mmu_gather.c:552
 exit_mmap+0x4b2/0x9f0 mm/mmap.c:1328
 __mmput+0x118/0x420 kernel/fork.c:1193
 exit_mm+0x221/0x2d0 kernel/exit.c:614
 do_exit+0x6cd/0x2360 kernel/exit.c:996
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
 __do_sys_exit_group kernel/exit.c:1162 [inline]
 __se_sys_exit_group kernel/exit.c:1160 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160
 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232
 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

Memory state around the buggy address:
 ffff888043c73300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888043c73380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888043c73400: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff888043c73480: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888043c73500: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/28 18:04 upstream 818bebeb63dd 41d151d4 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/08/22 14:06 upstream 818bebeb63dd 1e72964b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/08/01 13:59 upstream 02dc699f83d0 e611ffe1 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/07/29 03:36 upstream 3b5f4b83c4ab 19622d9d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/07/31 08:02 upstream 3708dd948844 aaffb173 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/07/31 08:02 upstream 3708dd948844 aaffb173 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: invalid-free in f_uac1_opts_c_srate_store
* Struck through repros no longer work on HEAD.