KASAN: invalid-free in f_uac1_opts_c_srate_store

Status: premoderation: reported C repro on 2026/07/27 01:32
Reported-by: syzbot+f52ace7e51ce767086e4@syzkaller.appspotmail.com
First crash: 12d, last: 1d12h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: invalid-free in f_uac1_opts_c_srate_store prio:normal usb 24 syz, C 4 6d21h 6d07h 0/29 upstream: reported C repro on 2026/08/02 03:46

Sample crash report:
==================================================================
BUG: KASAN: invalid-free in f_uac1_opts_c_srate_store+0x224/0x2b0 drivers/usb/gadget/function/f_uac1.c:1666
Free of addr ffff88810df83593 by task syz.2.17/383

CPU: 0 UID: 0 PID: 383 Comm: syz.2.17 Not tainted syzkaller #0 a4a563d0c71b2f3eba821a1af94cbf4bdc8174ca
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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_uac1_opts_c_srate_store+0x224/0x2b0 drivers/usb/gadget/function/f_uac1.c:1666
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x32c/0x490 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x762/0xfd0 fs/read_write.c:684
 ksys_write+0x145/0x260 fs/read_write.c:737
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x7f/0x90 fs/read_write.c:746
 x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 0033:0x7fadf0b9de99
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:00007ffd46b93468 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fadf0e25fa0 RCX: 00007fadf0b9de99
RDX: 0000000000000029 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007fadf0c33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fadf0e25fac R14: 00007fadf0e25fa0 R15: 00007fadf0e25fa0
 </TASK>

Allocated by task 383:
 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_uac1_opts_c_srate_store+0x11e/0x2b0 drivers/usb/gadget/function/f_uac1.c:1666
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x32c/0x490 fs/configfs/file.c:229
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x762/0xfd0 fs/read_write.c:684
 ksys_write+0x145/0x260 fs/read_write.c:737
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x7f/0x90 fs/read_write.c:746
 x64_sys_call+0x271c/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:2
 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 ffff88810df83580
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 19 bytes inside of
 42-byte region [ffff88810df83580, ffff88810df835aa)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10df83
flags: 0x4000000000000000(zone=1)
page_type: f5(slab)
raw: 4000000000000000 ffff8881000418c0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080200020 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 0x152cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 379, tgid 379 (syz-executor), ts 42256493503, free_ts 42256318391
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook+0x37d/0x3b0 mm/page_alloc.c:1863
 prep_new_page+0x2d/0x180 mm/page_alloc.c:1871
 get_page_from_freelist+0x4aea/0x4ba0 mm/page_alloc.c:3948
 __alloc_pages_noprof+0x35a/0x7e0 mm/page_alloc.c:5315
 alloc_slab_page+0x6b/0x1e0 mm/slub.c:-1
 allocate_slab+0x69/0x430 mm/slub.c:2687
 new_slab mm/slub.c:2741 [inline]
 ___slab_alloc+0x591/0x8c0 mm/slub.c:3934
 __slab_alloc mm/slub.c:4025 [inline]
 __slab_alloc_node mm/slub.c:4078 [inline]
 slab_alloc_node mm/slub.c:4239 [inline]
 __do_kmalloc_node mm/slub.c:4394 [inline]
 __kmalloc_node_noprof+0x2e7/0x500 mm/slub.c:4401
 __kvmalloc_node_noprof+0x128/0x300 mm/util.c:672
 allocate_hook_entries_size net/netfilter/core.c:61 [inline]
 nf_hook_entries_grow+0x284/0x740 net/netfilter/core.c:140
 nf_hook_entries_insert_raw+0x52/0x310 net/netfilter/core.c:204
 nf_nat_register_fn+0x219/0x640 net/netfilter/nf_nat_core.c:1255
 nf_nat_ipv4_register_fn+0x4f/0x70 net/netfilter/nf_nat_proto.c:861
 ipt_nat_register_lookups net/ipv4/netfilter/iptable_nat.c:77 [inline]
 iptable_nat_table_init+0x247/0x3d0 net/ipv4/netfilter/iptable_nat.c:121
 xt_find_table_lock+0x36c/0x460 net/netfilter/x_tables.c:1283
 xt_request_find_table_lock+0x2b/0x100 net/netfilter/x_tables.c:1308
page last free pid 379 tgid 379 stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1390 [inline]
 free_unref_page+0xbb8/0xf70 mm/page_alloc.c:2876
 __free_pages+0x6b/0x3b0 mm/page_alloc.c:5402
 vfree+0x3ea/0x5b0 mm/vmalloc.c:3410
 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:866 [inline]
 get_entries net/ipv4/netfilter/ip_tables.c:1022 [inline]
 do_ipt_get_ctl+0xef6/0x1210 net/ipv4/netfilter/ip_tables.c:1668
 nf_getsockopt+0x28b/0x2b0 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x15b/0x200 net/ipv4/ip_sockglue.c:1777
 tcp_getsockopt+0x103/0x130 net/ipv4/tcp.c:4705
 sock_common_getsockopt+0xb2/0xd0 net/core/sock.c:3831
 do_sock_getsockopt+0x3a4/0x6c0 net/socket.c:2398
 __sys_getsockopt net/socket.c:2427 [inline]
 __do_sys_getsockopt net/socket.c:2437 [inline]
 __se_sys_getsockopt net/socket.c:2434 [inline]
 __x64_sys_getsockopt+0x1d4/0x280 net/socket.c:2434
 x64_sys_call+0x10db/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:56
 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

Memory state around the buggy address:
 ffff88810df83480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810df83500: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88810df83580: 00 00 00 00 00 02 fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88810df83600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88810df83680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/27 02:12 android16-6.12 579215f16d4e 492bab15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/07/27 01:52 android16-6.12 579215f16d4e 492bab15 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/08/06 23:26 android16-6.12 749a6f9d41aa c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/08/04 08:56 android16-6.12 4f986595e48e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac1_opts_c_srate_store
2026/07/27 01:31 android16-6.12 579215f16d4e 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust KASAN: invalid-free in f_uac1_opts_c_srate_store
* Struck through repros no longer work on HEAD.