From: syzbot <syzbot+e91dc13b1b37759b3d9f@syzkaller.appspotmail.com>
To: jeff.johnson@oss.qualcomm.com, linux-kernel@vger.kernel.org,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
peterz@infradead.org, syzkaller-bugs@googlegroups.com,
tglx@kernel.org, toke@redhat.com, toke@toke.dk
Subject: [syzbot] [wireless?] KASAN: slab-use-after-free Read in tasklet_action_common
Date: Fri, 02 Oct 2026 10:14:33 -0700 [thread overview]
Message-ID: <6abfe679.b50370da.302ea9.000d.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: d24e8ac715de Merge tag 'net-7.3-rc6' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14361b15580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9d4242cb1c54cdf7
dashboard link: https://syzkaller.appspot.com/bug?extid=e91dc13b1b37759b3d9f
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12361b15580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=155bc725580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4ccd4fb94f0b/disk-d24e8ac7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/701ac3e3f73b/vmlinux-d24e8ac7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/976b7d839ef2/bzImage-d24e8ac7.xz
The issue was bisected to:
commit 1af8dc9ca726cf53767f9c0661171396f95c146a
Author: Toke Høiland-Jørgensen <toke@redhat.com>
Date: Tue Sep 8 17:05:18 2026 +0000
wifi: ath9k: Clean up device initialisation guards
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=145e5b15580000
final oops: https://syzkaller.appspot.com/x/report.txt?x=165e5b15580000
console output: https://syzkaller.appspot.com/x/log.txt?x=125e5b15580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e91dc13b1b37759b3d9f@syzkaller.appspotmail.com
Fixes: 1af8dc9ca726 ("wifi: ath9k: Clean up device initialisation guards")
==================================================================
BUG: KASAN: slab-use-after-free in tasklet_action_common+0x103/0x490 kernel/softirq.c:954
Read of size 8 at addr ffff888035947158 by task syz-executor/5756
CPU: 0 UID: 0 PID: 5756 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<IRQ>
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+0x117/0x150 mm/kasan/report.c:595
tasklet_action_common+0x103/0x490 kernel/softirq.c:954
handle_softirqs+0x226/0x860 kernel/softirq.c:645
do_softirq+0x77/0xd0 kernel/softirq.c:546
</IRQ>
<TASK>
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
spin_unlock_bh include/linux/spinlock.h:407 [inline]
tun_flow_delete_by_queue drivers/net/tun.c:379 [inline]
__tun_detach+0xccc/0x1900 drivers/net/tun.c:614
tun_detach drivers/net/tun.c:653 [inline]
tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3587
__fput+0x418/0xa50 fs/file_table.c:512
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:986
do_group_exit+0x22d/0x2f0 kernel/exit.c:1129
__do_sys_exit_group kernel/exit.c:1140 [inline]
__se_sys_exit_group kernel/exit.c:1138 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1138
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
RIP: 0033:0x7f558db9e159
Code: Unable to access opcode bytes at 0x7f558db9e12f.
RSP: 002b:00007ffc01d96c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f558dc35fb3 RCX: 00007f558db9e159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f558dc35fc5 R08: 0000000000000000 R09: 00000000000927c0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 00000000000927c0 R14: 0000000000015771 R15: 00007ffc01d96e10
</TASK>
Allocated by task 9:
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:409 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x321/0x600 mm/slub.c:5563
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
ath9k_init_wmi+0x4f/0x2b0 drivers/net/wireless/ath/ath9k/wmi.c:95
ath9k_htc_probe_device+0x1e5/0x2370 drivers/net/wireless/ath/ath9k/htc_drv_init.c:956
ath9k_htc_hw_init+0x32/0x70 drivers/net/wireless/ath/ath9k/htc_hst.c:532
ath9k_hif_usb_firmware_cb+0x214/0x4b0 drivers/net/wireless/ath/ath9k/hif_usb.c:1255
request_firmware_work_func+0xf7/0x2d0 drivers/base/firmware_loader/main.c:1164
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Freed by task 9:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
slab_free mm/slub.c:6508 [inline]
kfree+0x1c5/0x650 mm/slub.c:6801
ath9k_htc_probe_device+0x11a9/0x2370 drivers/net/wireless/ath/ath9k/htc_drv_init.c:978
ath9k_htc_hw_init+0x32/0x70 drivers/net/wireless/ath/ath9k/htc_hst.c:532
ath9k_hif_usb_firmware_cb+0x214/0x4b0 drivers/net/wireless/ath/ath9k/hif_usb.c:1255
request_firmware_work_func+0xf7/0x2d0 drivers/base/firmware_loader/main.c:1164
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff888035947000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 344 bytes inside of
freed 2048-byte region [ffff888035947000, ffff888035947800)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x35940
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b042000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042000 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1225, tgid 1225 (kworker/0:2), ts 87487181723
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:3347 [inline]
allocate_slab+0x7d/0x620 mm/slub.c:3462
new_slab mm/slub.c:3513 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7417
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
__do_kmalloc_node mm/slub.c:5413 [inline]
__kmalloc_node_track_caller_noprof+0x548/0x720 mm/slub.c:5545
kmalloc_reserve net/core/skbuff.c:637 [inline]
__alloc_skb+0x2c1/0x7a0 net/core/skbuff.c:715
alloc_skb include/linux/skbuff.h:1384 [inline]
mld_newpack+0x165/0xcb0 net/ipv6/mcast.c:1810
add_grhead net/ipv6/mcast.c:1921 [inline]
add_grec+0x119f/0x19d0 net/ipv6/mcast.c:2060
mld_send_initial_cr+0x288/0x550 net/ipv6/mcast.c:2305
mld_dad_work+0x3d/0x480 net/ipv6/mcast.c:2331
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
page last free pid 5650 tgid 5650 ts 85122206691 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
free_pages_prepare+0x9eb/0xaf0 mm/page_alloc.c:1463
__free_contig_range_common+0x174/0x340 mm/page_alloc.c:7072
__free_contig_range mm/page_alloc.c:7117 [inline]
free_pages_bulk+0x48/0x120 mm/page_alloc.c:5322
vm_area_free_pages mm/vmalloc.c:3461 [inline]
vfree+0x231/0x490 mm/vmalloc.c:3510
delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3414
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888035947000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888035947080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888035947100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888035947180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888035947200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
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#syz undup
next reply other threads:[~2026-10-02 17:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-02 17:14 syzbot [this message]
2026-10-02 23:03 ` Forwarded: [PATCH] wifi: ath9k: kill WMI event tasklet before freeing wmi syzbot
2026-10-02 23:09 ` Forwarded: [PATCH] wifi: ath9k: stop WMI event tasklet from rescheduling itself on probe failure syzbot
[not found] <20261002230311.102330-1-kartikey406@gmail.com>
2026-10-03 1:36 ` [syzbot] [wireless?] KASAN: slab-use-after-free Read in tasklet_action_common syzbot
[not found] <20261002230851.103334-1-kartikey406@gmail.com>
2026-10-03 2:02 ` syzbot
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