[v6.1] KASAN: invalid-free in f_uac2_opts_p_srate_store

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=164df479580000
kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f
dashboard link: https://syzkaller.appspot.com/bug?extid=1d3a0ce016764453da97
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7cd9b1875376/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4b5d35d18c31/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d5ee64c2af77/Image-e4f7d8be.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1d3a0c...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: invalid-free in slab_free mm/slub.c:3687 [inline]
BUG: KASAN: invalid-free in __kmem_cache_free+0xbc/0x21c mm/slub.c:3700
Free of addr ffff0000f374c912 by task syz.1.1077/8951

CPU: 1 PID: 8951 Comm: syz.1.1077 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Call trace:
dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack+0x30/0x40 lib/dump_stack.c:88
dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
print_address_description+0x88/0x218 mm/kasan/report.c:316
print_report+0x50/0x68 mm/kasan/report.c:420
kasan_report_invalid_free+0x98/0xe4 mm/kasan/report.c:489
____kasan_slab_free+0x168/0x1b0 mm/kasan/common.c:-1
__kasan_slab_free+0x18/0x28 mm/kasan/common.c:245
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xbc/0x21c mm/slub.c:3700
kfree+0xd0/0x1a8 mm/slab_common.c:988
f_uac2_opts_p_srate_store+0xe4/0x27c drivers/usb/gadget/function/f_uac2.c:2078
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x260/0x338 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x3c8/0x7c8 fs/read_write.c:584
ksys_write+0x12c/0x228 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Allocated by task 8951:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slab_common.c:936 [inline]
__kmalloc_node_track_caller+0xcc/0x174 mm/slab_common.c:956
kstrdup+0x68/0xb0 mm/util.c:61
f_uac2_opts_p_srate_store+0x168/0x27c drivers/usb/gadget/function/f_uac2.c:2078
flush_write_buffer fs/configfs/file.c:207 [inline]
configfs_write_iter+0x260/0x338 fs/configfs/file.c:229
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x3c8/0x7c8 fs/read_write.c:584
ksys_write+0x12c/0x228 fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Last potentially related work creation:
kasan_save_stack+0x40/0x70 mm/kasan/common.c:46
__kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496
kvfree_call_rcu+0xb4/0x6f0 kernel/rcu/tree.c:3405
cfg80211_update_known_bss+0x11c/0x7fc net/wireless/scan.c:-1
cfg80211_bss_update+0x150/0x1ccc net/wireless/scan.c:1847
cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2509 [inline]
cfg80211_inform_bss_frame_data+0x890/0x10f8 net/wireless/scan.c:2542
ieee80211_bss_info_update+0x640/0xa7c net/mac80211/scan.c:190
ieee80211_rx_bss_info net/mac80211/ibss.c:1120 [inline]
ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1609 [inline]
ieee80211_ibss_rx_queued_mgmt+0x143c/0x2608 net/mac80211/ibss.c:1638
ieee80211_iface_process_skb net/mac80211/iface.c:1679 [inline]
ieee80211_iface_work+0x5a8/0xa4c net/mac80211/iface.c:1733
cfg80211_wiphy_work+0x1e0/0x220 net/wireless/core.c:433
process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
kthread+0x254/0x2e0 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

Second to last potentially related work creation:
kasan_save_stack+0x40/0x70 mm/kasan/common.c:46
__kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486
kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496
kvfree_call_rcu+0xb4/0x6f0 kernel/rcu/tree.c:3405
kernfs_unlink_open_file+0x370/0x41c fs/kernfs/file.c:653
kernfs_fop_release+0x128/0x194 fs/kernfs/file.c:825
__fput+0x1b4/0x7b0 fs/file_table.c:320
____fput+0x20/0x30 fs/file_table.c:348
task_work_run+0x1f4/0x280 kernel/task_work.c:203
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151
prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline]
exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline]
el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the object at ffff0000f374c900
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 18 bytes inside of
128-byte region [ffff0000f374c900, ffff0000f374c980)

The buggy address belongs to the physical page:
page:00000000b9071ac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13374c
flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000200 fffffc0003cfa500 dead000000000002 ffff0000c0002300
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff0000f374c800: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000f374c880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000f374c900: 00 00 00 00 00 07 fc fc fc fc fc fc fc fc fc fc
^
ffff0000f374c980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000f374ca00: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: e4f7d8be268e Linux 6.1.182
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=13eab225580000

kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f
dashboard link: https://syzkaller.appspot.com/bug?extid=1d3a0ce016764453da97
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17eab225580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11fe5149580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7cd9b1875376/disk-e4f7d8be.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4b5d35d18c31/vmlinux-e4f7d8be.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d5ee64c2af77/Image-e4f7d8be.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1d3a0c...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: invalid-free in slab_free mm/slub.c:3687 [inline]
BUG: KASAN: invalid-free in __kmem_cache_free+0xbc/0x21c mm/slub.c:3700

Free of addr ffff0000caa3a212 by task syz.0.17/4491

CPU: 0 PID: 4491 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026

Allocated by task 4491:

The buggy address belongs to the object at ffff0000caa3a200

which belongs to the cache kmalloc-128 of size 128
The buggy address is located 18 bytes inside of

128-byte region [ffff0000caa3a200, ffff0000caa3a280)

The buggy address belongs to the physical page:

page:0000000061dd9165 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10aa3a

flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff)

raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c0002300

raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff0000caa3a100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff0000caa3a180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000caa3a200: 00 00 00 00 00 07 fc fc fc fc fc fc fc fc fc fc
^
ffff0000caa3a280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff0000caa3a300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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