[v5.15] KASAN: use-after-free Read in usa49_glocont_callback
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syzbot
Aug 4, 2026, 1:41:41 PM (10 days ago) Aug 4
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 6e2fd6534337 Linux 5.15.213
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=175c4bb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=87dbffac2a6e7f925710
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d7b46606b13d/disk-6e2fd653.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/da120fdeb081/vmlinux-6e2fd653.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c2643457e3f/bzImage-6e2fd653.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87dbff...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1044
Read of size 4 at addr ffff888020b57ab0 by task kworker/1:20/6301
CPU: 1 PID: 6301 Comm: kworker/1:20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
<IRQ>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
print_address_description+0x60/0x2d0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xdf/0x130 mm/kasan/report.c:451
usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1044
__usb_hcd_giveback_urb+0x35d/0x520 drivers/usb/core/hcd.c:1672
dummy_timer+0xa41/0x33c0 drivers/usb/gadget/udc/dummy_hcd.c:1998
call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
expire_timers kernel/time/timer.c:1699 [inline]
__run_timers+0x56c/0x810 kernel/time/timer.c:1970
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
handle_softirqs+0x336/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_unlock+0xc90/0x10f0 kernel/printk/printk.c:2749
Code: 75 11 e8 13 df 18 00 4d 85 e4 75 16 e8 09 df 18 00 eb 15 e8 02 df 18 00 e8 dd f6 5f 08 4d 85 e4 74 ea e8 f3 de 18 00 fb 31 ff <89> de e8 49 e2 18 00 85 db 0f 94 c0 22 44 24 1f 3c 01 75 1f e8 d7
RSP: 0018:ffffc90003976de0 EFLAGS: 00000246
RAX: ffffffff81601dbd RBX: 0000000000000000 RCX: 0000000000100000
RDX: ffffc90017c8a000 RSI: 000000000000da37 RDI: 0000000000000000
RBP: ffffc90003977050 R08: ffffffff901ee0c7 R09: 1ffffffff203dc18
R10: dffffc0000000000 R11: fffffbfff203dc19 R12: 0000000000000200
R13: 0000000000000069 R14: 0000000000000000 R15: dffffc0000000000
vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
dev_vprintk_emit+0x2c2/0x360 drivers/base/core.c:4665
dev_printk_emit+0xeb/0x140 drivers/base/core.c:4676
_dev_info+0x11b/0x170 drivers/base/core.c:4734
usb_serial_device_remove+0x149/0x1e0 drivers/usb/serial/bus.c:99
__device_release_driver drivers/base/dd.c:1247 [inline]
device_release_driver_internal+0x44c/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_serial_disconnect+0x294/0x480 drivers/usb/serial/usb-serial.c:1202
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
__device_release_driver drivers/base/dd.c:1249 [inline]
device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2287
hub_port_connect drivers/usb/core/hub.c:5341 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5881
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Allocated by task 21:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:607 [inline]
kzalloc include/linux/slab.h:738 [inline]
keyspan_port_probe+0xa7/0xd10 drivers/usb/serial/keyspan.c:2890
usb_serial_device_probe+0xd6/0x2d0 drivers/usb/serial/bus.c:47
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:999
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3427
usb_serial_probe+0x265c/0x2c90 drivers/usb/serial/usb-serial.c:1149
usb_probe_interface+0x5be/0xae0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:999
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3427
usb_set_configuration+0x19d5/0x2030 drivers/usb/core/message.c:2223
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x126/0x250 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:999
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3427
usb_new_device+0x9f6/0x15d0 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5497 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x2b8d/0x5260 drivers/usb/core/hub.c:5881
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Freed by task 6301:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kfree+0xef/0x2a0 mm/slub.c:4564
usb_serial_device_remove+0x11c/0x1e0 drivers/usb/serial/bus.c:97
__device_release_driver drivers/base/dd.c:1247 [inline]
device_release_driver_internal+0x44c/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_serial_disconnect+0x294/0x480 drivers/usb/serial/usb-serial.c:1202
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
__device_release_driver drivers/base/dd.c:1249 [inline]
device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2287
hub_port_connect drivers/usb/core/hub.c:5341 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5881
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Last potentially related work creation:
kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
__call_rcu kernel/rcu/tree.c:3011 [inline]
call_rcu+0x189/0x900 kernel/rcu/tree.c:3091
addrconf_ifdown+0x1724/0x19f0 net/ipv6/addrconf.c:3939
addrconf_notify+0x445/0xf20 net/ipv6/addrconf.c:-1
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2074 [inline]
call_netdevice_notifiers net/core/dev.c:2088 [inline]
unregister_netdevice_many+0x109b/0x1a40 net/core/dev.c:11160
default_device_exit_batch+0x364/0x3c0 net/core/dev.c:11693
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x78e/0xba0 net/core/net_namespace.c:635
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Second to last potentially related work creation:
kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
insert_work+0x54/0x3d0 kernel/workqueue.c:1366
__queue_work+0x90b/0xc80 kernel/workqueue.c:1532
queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
queue_work include/linux/workqueue.h:512 [inline]
call_usermodehelper_exec+0x2e3/0x520 kernel/umh.c:435
kobject_uevent_env+0x67b/0x890 lib/kobject_uevent.c:633
disk_uevent+0x27e/0x430 block/genhd.c:367
device_add_disk+0xa31/0xd00 block/genhd.c:520
add_disk include/linux/genhd.h:200 [inline]
loop_add+0x5e7/0x890 drivers/block/loop.c:2431
loop_init+0x173/0x220 drivers/block/loop.c:2615
do_one_initcall+0x272/0x730 init/main.c:1315
do_initcall_level+0x13d/0x1f0 init/main.c:1388
do_initcalls+0x4b/0x90 init/main.c:1404
kernel_init_freeable+0x3d5/0x560 init/main.c:1628
kernel_init+0x19/0x1b0 init/main.c:1519
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
The buggy address belongs to the object at ffff888020b57a00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 176 bytes inside of
192-byte region [ffff888020b57a00, ffff888020b57ac0)
The buggy address belongs to the page:
page:ffffea000082d5c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20b57
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 0000000300000001 ffff888016c41a00
raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x12c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 7790438147, free_ts 0
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
__alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
__alloc_pages_node include/linux/gfp.h:570 [inline]
alloc_slab_page mm/slub.c:1782 [inline]
allocate_slab mm/slub.c:1917 [inline]
new_slab+0xb6/0x4b0 mm/slub.c:1980
___slab_alloc+0x807/0xdd0 mm/slub.c:3013
__slab_alloc mm/slub.c:3100 [inline]
slab_alloc_node mm/slub.c:3191 [inline]
__kmalloc_node+0x142/0x3a0 mm/slub.c:4456
kmalloc_array_node include/linux/slab.h:700 [inline]
kcalloc_node include/linux/slab.h:705 [inline]
sbitmap_init_node+0x2a6/0x6b0 lib/sbitmap.c:114
blk_mq_alloc_hctx block/blk-mq.c:2835 [inline]
blk_mq_alloc_and_init_hctx block/blk-mq.c:3220 [inline]
blk_mq_realloc_hw_ctxs+0x7b6/0x1730 block/blk-mq.c:3272
blk_mq_init_allocated_queue+0x3db/0x17b0 block/blk-mq.c:3333
blk_mq_init_queue_data block/blk-mq.c:3168 [inline]
__blk_mq_alloc_disk+0x81/0x150 block/blk-mq.c:3188
loop_add+0x288/0x890 drivers/block/loop.c:2378
loop_init+0x173/0x220 drivers/block/loop.c:2615
do_one_initcall+0x272/0x730 init/main.c:1315
do_initcall_level+0x13d/0x1f0 init/main.c:1388
do_initcalls+0x4b/0x90 init/main.c:1404
kernel_init_freeable+0x3d5/0x560 init/main.c:1628
kernel_init+0x19/0x1b0 init/main.c:1519
page_owner free stack trace missing
Memory state around the buggy address:
ffff888020b57980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888020b57a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888020b57a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888020b57b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888020b57b80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 75 11 jne 0x13
2: e8 13 df 18 00 call 0x18df1a
7: 4d 85 e4 test %r12,%r12
a: 75 16 jne 0x22
c: e8 09 df 18 00 call 0x18df1a
11: eb 15 jmp 0x28
13: e8 02 df 18 00 call 0x18df1a
18: e8 dd f6 5f 08 call 0x85ff6fa
1d: 4d 85 e4 test %r12,%r12
20: 74 ea je 0xc
22: e8 f3 de 18 00 call 0x18df1a
27: fb sti
28: 31 ff xor %edi,%edi
* 2a: 89 de mov %ebx,%esi <-- trapping instruction
2c: e8 49 e2 18 00 call 0x18e27a
31: 85 db test %ebx,%ebx
33: 0f 94 c0 sete %al
36: 22 44 24 1f and 0x1f(%rsp),%al
3a: 3c 01 cmp $0x1,%al
3c: 75 1f jne 0x5d
3e: e8 .byte 0xe8
3f: d7 xlat %ds:(%rbx)
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 6e2fd6534337 Linux 5.15.213
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=175c4bb9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=87dbffac2a6e7f925710
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d7b46606b13d/disk-6e2fd653.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/da120fdeb081/vmlinux-6e2fd653.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c2643457e3f/bzImage-6e2fd653.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87dbff...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1044
Read of size 4 at addr ffff888020b57ab0 by task kworker/1:20/6301
CPU: 1 PID: 6301 Comm: kworker/1:20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
<IRQ>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
print_address_description+0x60/0x2d0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:434 [inline]
kasan_report+0xdf/0x130 mm/kasan/report.c:451
usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1044
__usb_hcd_giveback_urb+0x35d/0x520 drivers/usb/core/hcd.c:1672
dummy_timer+0xa41/0x33c0 drivers/usb/gadget/udc/dummy_hcd.c:1998
call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
expire_timers kernel/time/timer.c:1699 [inline]
__run_timers+0x56c/0x810 kernel/time/timer.c:1970
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
handle_softirqs+0x336/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:console_unlock+0xc90/0x10f0 kernel/printk/printk.c:2749
Code: 75 11 e8 13 df 18 00 4d 85 e4 75 16 e8 09 df 18 00 eb 15 e8 02 df 18 00 e8 dd f6 5f 08 4d 85 e4 74 ea e8 f3 de 18 00 fb 31 ff <89> de e8 49 e2 18 00 85 db 0f 94 c0 22 44 24 1f 3c 01 75 1f e8 d7
RSP: 0018:ffffc90003976de0 EFLAGS: 00000246
RAX: ffffffff81601dbd RBX: 0000000000000000 RCX: 0000000000100000
RDX: ffffc90017c8a000 RSI: 000000000000da37 RDI: 0000000000000000
RBP: ffffc90003977050 R08: ffffffff901ee0c7 R09: 1ffffffff203dc18
R10: dffffc0000000000 R11: fffffbfff203dc19 R12: 0000000000000200
R13: 0000000000000069 R14: 0000000000000000 R15: dffffc0000000000
vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
dev_vprintk_emit+0x2c2/0x360 drivers/base/core.c:4665
dev_printk_emit+0xeb/0x140 drivers/base/core.c:4676
_dev_info+0x11b/0x170 drivers/base/core.c:4734
usb_serial_device_remove+0x149/0x1e0 drivers/usb/serial/bus.c:99
__device_release_driver drivers/base/dd.c:1247 [inline]
device_release_driver_internal+0x44c/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_serial_disconnect+0x294/0x480 drivers/usb/serial/usb-serial.c:1202
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
__device_release_driver drivers/base/dd.c:1249 [inline]
device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2287
hub_port_connect drivers/usb/core/hub.c:5341 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5881
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Allocated by task 21:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
____kasan_kmalloc mm/kasan/common.c:513 [inline]
__kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
kmalloc include/linux/slab.h:607 [inline]
kzalloc include/linux/slab.h:738 [inline]
keyspan_port_probe+0xa7/0xd10 drivers/usb/serial/keyspan.c:2890
usb_serial_device_probe+0xd6/0x2d0 drivers/usb/serial/bus.c:47
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:999
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3427
usb_serial_probe+0x265c/0x2c90 drivers/usb/serial/usb-serial.c:1149
usb_probe_interface+0x5be/0xae0 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:999
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3427
usb_set_configuration+0x19d5/0x2030 drivers/usb/core/message.c:2223
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x126/0x250 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x276/0xc70 drivers/base/dd.c:595
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:775
driver_probe_device+0x4f/0x420 drivers/base/dd.c:805
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:927
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:999
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3427
usb_new_device+0x9f6/0x15d0 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5497 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x2b8d/0x5260 drivers/usb/core/hub.c:5881
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Freed by task 6301:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xec/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kfree+0xef/0x2a0 mm/slub.c:4564
usb_serial_device_remove+0x11c/0x1e0 drivers/usb/serial/bus.c:97
__device_release_driver drivers/base/dd.c:1247 [inline]
device_release_driver_internal+0x44c/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_serial_disconnect+0x294/0x480 drivers/usb/serial/usb-serial.c:1202
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
__device_release_driver drivers/base/dd.c:1249 [inline]
device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2287
hub_port_connect drivers/usb/core/hub.c:5341 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5881
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Last potentially related work creation:
kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
__call_rcu kernel/rcu/tree.c:3011 [inline]
call_rcu+0x189/0x900 kernel/rcu/tree.c:3091
addrconf_ifdown+0x1724/0x19f0 net/ipv6/addrconf.c:3939
addrconf_notify+0x445/0xf20 net/ipv6/addrconf.c:-1
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
call_netdevice_notifiers_extack net/core/dev.c:2074 [inline]
call_netdevice_notifiers net/core/dev.c:2088 [inline]
unregister_netdevice_many+0x109b/0x1a40 net/core/dev.c:11160
default_device_exit_batch+0x364/0x3c0 net/core/dev.c:11693
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x78e/0xba0 net/core/net_namespace.c:635
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Second to last potentially related work creation:
kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
insert_work+0x54/0x3d0 kernel/workqueue.c:1366
__queue_work+0x90b/0xc80 kernel/workqueue.c:1532
queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
queue_work include/linux/workqueue.h:512 [inline]
call_usermodehelper_exec+0x2e3/0x520 kernel/umh.c:435
kobject_uevent_env+0x67b/0x890 lib/kobject_uevent.c:633
disk_uevent+0x27e/0x430 block/genhd.c:367
device_add_disk+0xa31/0xd00 block/genhd.c:520
add_disk include/linux/genhd.h:200 [inline]
loop_add+0x5e7/0x890 drivers/block/loop.c:2431
loop_init+0x173/0x220 drivers/block/loop.c:2615
do_one_initcall+0x272/0x730 init/main.c:1315
do_initcall_level+0x13d/0x1f0 init/main.c:1388
do_initcalls+0x4b/0x90 init/main.c:1404
kernel_init_freeable+0x3d5/0x560 init/main.c:1628
kernel_init+0x19/0x1b0 init/main.c:1519
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
The buggy address belongs to the object at ffff888020b57a00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 176 bytes inside of
192-byte region [ffff888020b57a00, ffff888020b57ac0)
The buggy address belongs to the page:
page:ffffea000082d5c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20b57
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 0000000300000001 ffff888016c41a00
raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x12c00(GFP_NOIO|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 7790438147, free_ts 0
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
__alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
__alloc_pages_node include/linux/gfp.h:570 [inline]
alloc_slab_page mm/slub.c:1782 [inline]
allocate_slab mm/slub.c:1917 [inline]
new_slab+0xb6/0x4b0 mm/slub.c:1980
___slab_alloc+0x807/0xdd0 mm/slub.c:3013
__slab_alloc mm/slub.c:3100 [inline]
slab_alloc_node mm/slub.c:3191 [inline]
__kmalloc_node+0x142/0x3a0 mm/slub.c:4456
kmalloc_array_node include/linux/slab.h:700 [inline]
kcalloc_node include/linux/slab.h:705 [inline]
sbitmap_init_node+0x2a6/0x6b0 lib/sbitmap.c:114
blk_mq_alloc_hctx block/blk-mq.c:2835 [inline]
blk_mq_alloc_and_init_hctx block/blk-mq.c:3220 [inline]
blk_mq_realloc_hw_ctxs+0x7b6/0x1730 block/blk-mq.c:3272
blk_mq_init_allocated_queue+0x3db/0x17b0 block/blk-mq.c:3333
blk_mq_init_queue_data block/blk-mq.c:3168 [inline]
__blk_mq_alloc_disk+0x81/0x150 block/blk-mq.c:3188
loop_add+0x288/0x890 drivers/block/loop.c:2378
loop_init+0x173/0x220 drivers/block/loop.c:2615
do_one_initcall+0x272/0x730 init/main.c:1315
do_initcall_level+0x13d/0x1f0 init/main.c:1388
do_initcalls+0x4b/0x90 init/main.c:1404
kernel_init_freeable+0x3d5/0x560 init/main.c:1628
kernel_init+0x19/0x1b0 init/main.c:1519
page_owner free stack trace missing
Memory state around the buggy address:
ffff888020b57980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888020b57a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888020b57a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff888020b57b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888020b57b80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 75 11 jne 0x13
2: e8 13 df 18 00 call 0x18df1a
7: 4d 85 e4 test %r12,%r12
a: 75 16 jne 0x22
c: e8 09 df 18 00 call 0x18df1a
11: eb 15 jmp 0x28
13: e8 02 df 18 00 call 0x18df1a
18: e8 dd f6 5f 08 call 0x85ff6fa
1d: 4d 85 e4 test %r12,%r12
20: 74 ea je 0xc
22: e8 f3 de 18 00 call 0x18df1a
27: fb sti
28: 31 ff xor %edi,%edi
* 2a: 89 de mov %ebx,%esi <-- trapping instruction
2c: e8 49 e2 18 00 call 0x18e27a
31: 85 db test %ebx,%ebx
33: 0f 94 c0 sete %al
36: 22 44 24 1f and 0x1f(%rsp),%al
3a: 3c 01 cmp $0x1,%al
3c: 75 1f jne 0x5d
3e: e8 .byte 0xe8
3f: d7 xlat %ds:(%rbx)
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
Aug 8, 2026, 4:05:41 PM (6 days ago) Aug 8
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: aabd761612db Linux 5.15.215
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15cd6132580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15210149580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f636f56d3662/disk-aabd7616.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f1a46620f40c/vmlinux-aabd7616.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9b78bb48b022/bzImage-aabd7616.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87dbff...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1044
Read of size 4 at addr ffff8881437dbbb0 by task kworker/1:0/21
CPU: 1 PID: 21 Comm: kworker/1:0 Not tainted syzkaller #0
RSP: 0018:ffffc90000db6de0 EFLAGS: 00000246
RAX: ffffffff81601dbd RBX: 0000000000000000 RCX: ffff888017a09dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000db7050 R08: ffffffff901ee0c7 R09: 1ffffffff203dc18
Allocated by task 4275:
Freed by task 21:
kasan_save_stack mm/kasan/common.c:38 [inline]
The buggy address belongs to the object at ffff8881437dbb00
flags: 0x57ff00000000200(slab|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000200 ffffea00050df488 ffff888140000648 ffff888016c41a00
raw: ffff8881437db800 0000000000100007 00000001ffffffff 0000000000000000
alloc_slab_page mm/slub.c:1780 [inline]
allocate_slab mm/slub.c:1917 [inline]
new_slab+0xc0/0x4b0 mm/slub.c:1980
kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250
kobject_uevent_env+0x658/0x890 lib/kobject_uevent.c:629
kernel_add_sysfs_param+0xfb/0x120 kernel/params.c:802
param_sysfs_builtin+0x183/0x200 kernel/params.c:837
param_sysfs_init+0x66/0x70 kernel/params.c:958
ffff8881437dbb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881437dbb80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff8881437dbc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881437dbc80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: aabd761612db Linux 5.15.215
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15cd6132580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=87dbffac2a6e7f925710
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=100abfb9580000
dashboard link: https://syzkaller.appspot.com/bug?extid=87dbffac2a6e7f925710
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15210149580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f636f56d3662/disk-aabd7616.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f1a46620f40c/vmlinux-aabd7616.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9b78bb48b022/bzImage-aabd7616.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+87dbff...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1044
CPU: 1 PID: 21 Comm: kworker/1:0 Not tainted syzkaller #0
RAX: ffffffff81601dbd RBX: 0000000000000000 RCX: ffff888017a09dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000db7050 R08: ffffffff901ee0c7 R09: 1ffffffff203dc18
kasan_save_stack mm/kasan/common.c:38 [inline]
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 176 bytes inside of
192-byte region [ffff8881437dbb00, ffff8881437dbbc0)
The buggy address is located 176 bytes inside of
The buggy address belongs to the page:
page:ffffea00050df6c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881437db800 pfn:0x1437db
flags: 0x57ff00000000200(slab|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000200 ffffea00050df488 ffff888140000648 ffff888016c41a00
raw: ffff8881437db800 0000000000100007 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 2328826578, free_ts 0
page_owner tracks the page as allocated
prep_new_page mm/page_alloc.c:2426 [inline]
get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
__alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
__alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
alloc_slab_page mm/slub.c:1780 [inline]
allocate_slab mm/slub.c:1917 [inline]
new_slab+0xc0/0x4b0 mm/slub.c:1980
___slab_alloc+0x807/0xdd0 mm/slub.c:3013
__slab_alloc mm/slub.c:3100 [inline]
slab_alloc_node mm/slub.c:3191 [inline]
slab_alloc mm/slub.c:3233 [inline]
__slab_alloc mm/slub.c:3100 [inline]
slab_alloc_node mm/slub.c:3191 [inline]
kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250
kmalloc include/linux/slab.h:607 [inline]
kzalloc include/linux/slab.h:738 [inline]
call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365
kzalloc include/linux/slab.h:738 [inline]
kobject_uevent_env+0x658/0x890 lib/kobject_uevent.c:629
kernel_add_sysfs_param+0xfb/0x120 kernel/params.c:802
param_sysfs_builtin+0x183/0x200 kernel/params.c:837
param_sysfs_init+0x66/0x70 kernel/params.c:958
do_one_initcall+0x272/0x730 init/main.c:1315
do_initcall_level+0x13d/0x1f0 init/main.c:1388
do_initcalls+0x4b/0x90 init/main.c:1404
kernel_init_freeable+0x3d5/0x560 init/main.c:1628
kernel_init+0x19/0x1b0 init/main.c:1519
page_owner free stack trace missing
Memory state around the buggy address:
ffff8881437dba80: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
do_initcall_level+0x13d/0x1f0 init/main.c:1388
do_initcalls+0x4b/0x90 init/main.c:1404
kernel_init_freeable+0x3d5/0x560 init/main.c:1628
kernel_init+0x19/0x1b0 init/main.c:1519
page_owner free stack trace missing
Memory state around the buggy address:
ffff8881437dbb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881437dbb80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff8881437dbc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881437dbc80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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