KASAN: invalid-free in f_uac2_opts_p_srate_store

Status: premoderation: reported C repro on 2026/07/28 00:18
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+98b3f872ff1e26f7551a@syzkaller.appspotmail.com
First crash: 49d, last: 4d09h
Bug presence (2)
Date Name Commit Repro Result
2026/09/04 lts (merge base) ff43460784b7 C [report] KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/09/04 upstream (ToT) 986c24e0fe44 C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: invalid-free in f_uac2_opts_p_srate_store prio:normal usb 24 syz, C error 156 17d 47d 0/29 upstream: reported C repro on 2026/07/30 00:09
linux-6.1 KASAN: invalid-free in f_uac2_opts_p_srate_store 24 syz, C 6 27d 33d 0/3 upstream: reported C repro on 2026/08/13 09:55
android-6-1 KASAN: invalid-free in f_uac2_opts_p_srate_store origin:upstream 24 syz, C 9 24d 44d 0/2 upstream: reported C repro on 2026/08/01 22:27

Sample crash report:
BUG: KASAN: invalid-free in f_uac2_opts_p_srate_store+0x224/0x2b0 drivers/usb/gadget/function/f_uac2.c:2087
Free of addr ffff88810b69b681 by task syz-executor267/312

CPU: 0 UID: 0 PID: 312 Comm: syz-executor267 Not tainted syzkaller #0 053bc84e93bdef9c6c9615cbace6655003d8d143
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 print_address_description+0x71/0x210 mm/kasan/report.c:377
 print_report+0x4a/0x70 mm/kasan/report.c:481
 kasan_report_invalid_free+0x11e/0x160 mm/kasan/report.c:556
 check_slab_allocation+0xdf/0xf0 include/linux/page-flags.h:-1
 __kasan_slab_pre_free+0x36/0x50 mm/kasan/common.c:257
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2390 [inline]
 slab_free mm/slub.c:4714 [inline]
 kfree+0xf8/0x440 mm/slub.c:4875
 f_uac2_opts_p_srate_store+0x224/0x2b0 drivers/usb/gadget/function/f_uac2.c:2087
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x32c/0x490 fs/configfs/file.c:229
 do_iter_readv_writev+0x629/0x820 fs/read_write.c:-1
 vfs_writev+0x4a5/0xe90 fs/read_write.c:1076
 do_pwritev fs/read_write.c:1177 [inline]
 __do_sys_pwritev fs/read_write.c:1224 [inline]
 __se_sys_pwritev fs/read_write.c:1219 [inline]
 __x64_sys_pwritev+0x19f/0x2c0 fs/read_write.c:1219
 x64_sys_call+0x29bc/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:297
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fe17fedccf9
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe9a201cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000128
RAX: ffffffffffffffda RBX: d7ceab0f2931992c RCX: 00007fe17fedccf9
RDX: 0000000000000001 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000006 R09: 00007ffe9a201df8
R10: 0000000000000001 R11: 0000000000000246 R12: 00007ffe9a201de8
R13: 0000000000000002 R14: 00007fe17ff6dca0 R15: 0000000000000002
 </TASK>

Allocated by task 312:
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:261 [inline]
 __do_kmalloc_node mm/slub.c:4395 [inline]
 __kmalloc_node_track_caller_noprof+0x24e/0x4f0 mm/slub.c:4414
 kstrdup+0x4d/0x130 mm/util.c:70
 f_uac2_opts_p_srate_store+0x11e/0x2b0 drivers/usb/gadget/function/f_uac2.c:2087
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x32c/0x490 fs/configfs/file.c:229
 do_iter_readv_writev+0x629/0x820 fs/read_write.c:-1
 vfs_writev+0x4a5/0xe90 fs/read_write.c:1076
 do_pwritev fs/read_write.c:1177 [inline]
 __do_sys_pwritev fs/read_write.c:1224 [inline]
 __se_sys_pwritev fs/read_write.c:1219 [inline]
 __x64_sys_pwritev+0x19f/0x2c0 fs/read_write.c:1219
 x64_sys_call+0x29bc/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:297
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The buggy address belongs to the object at ffff88810b69b680
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 1 bytes inside of
 10-byte region [ffff88810b69b680, ffff88810b69b68a)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10b69b
anon flags: 0x4000000000000000(zone=1)
page_type: f5(slab)
raw: 4000000000000000 ffff888100041640 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080800080 00000001f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 13, tgid 13 (kworker/u8:1), ts 2583057062, free_ts 0
 create_dummy_stack mm/page_owner.c:93 [inline]
 register_dummy_stack+0x99/0x110 mm/page_owner.c:99
 init_page_owner+0x36/0x840 mm/page_owner.c:117
 invoke_init_callbacks mm/page_ext.c:152 [inline]
 page_ext_init+0x3f8/0x44b mm/page_ext.c:501
 mm_core_init+0x4b/0x7b mm/mm_init.c:2670
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88810b69b580: fa fb fc fc fa fb fc fc 00 00 fc fc fa fb fc fc
 ffff88810b69b600: fa fb fc fc fa fb fc fc 00 01 fc fc fa fb fc fc
>ffff88810b69b680: 00 02 fc fc fa fb fc fc fa fb fc fc fa fb fc fc
                   ^
 ffff88810b69b700: 00 00 fc fc fa fb fc fc fa fb fc fc fa fb fc fc
 

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/11 02:16 android16-6.12 de3d34623482 1fe56c0a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/08/24 19:23 android16-6.12 7f32621dc7d3 b55bd4c3 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/07/30 08:55 android16-6.12 f1c9c21d1c2f 2377cd3d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/07/29 19:27 android16-6.12 f1c9c21d1c2f 6ef5c1e2 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/07/29 18:50 android16-6.12 f1c9c21d1c2f 6ef5c1e2 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/08/18 14:02 android16-6.12 83f7e9ec53bb 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/07/30 04:52 android16-6.12 f1c9c21d1c2f 6ef5c1e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
2026/07/28 00:18 android16-6.12 a12ab5a23a35 aae9036b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac2_opts_p_srate_store
* Struck through repros no longer work on HEAD.