[v5.15] KASAN: use-after-free Read in vhci_shutdown_connection

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 674f684f7c61 Linux 5.15.212
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=163a1449580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=121ca3ec4261dcaff785
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/f55be2937b89/disk-674f684f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a19fb0ffc049/vmlinux-674f684f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/365d4529a007/bzImage-674f684f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+121ca3...@syzkaller.appspotmail.com

vhci_hcd: disconnect device
vhci_hcd: stop threads
==================================================================
BUG: KASAN: use-after-free in vhci_shutdown_connection+0x211/0x580 drivers/usb/usbip/vhci_hcd.c:1057
Read of size 8 at addr ffff8880241c49b0 by task kworker/u4:8/6746

CPU: 0 PID: 6746 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: usbip_event event_handler
Call Trace:
<TASK>
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
vhci_shutdown_connection+0x211/0x580 drivers/usb/usbip/vhci_hcd.c:1057
event_handler+0x299/0x460 drivers/usb/usbip/usbip_event.c:79
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 1:
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:612 [inline]
kzalloc include/linux/slab.h:738 [inline]
__usb_create_hcd+0x5f/0x830 drivers/usb/core/hcd.c:2587
vhci_hcd_probe+0xff/0x370 drivers/usb/usbip/vhci_hcd.c:1376
platform_probe+0x137/0x1c0 drivers/base/platform.c:1391
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
platform_device_add+0x4bf/0x830 drivers/base/platform.c:712
vhci_hcd_init+0x3c7/0x500 drivers/usb/usbip/vhci_hcd.c:1571
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

Freed by task 8959:
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
vhci_hcd_remove+0xe0/0x100 drivers/usb/usbip/vhci_hcd.c:1434
platform_remove+0x92/0xe0 drivers/base/platform.c:1413
__device_release_driver drivers/base/dd.c:1247 [inline]
device_release_driver_internal+0x44c/0x710 drivers/base/dd.c:1282
unbind_store+0x2e2/0x300 drivers/base/bus.c:193
kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x748/0xd70 fs/read_write.c:594
ksys_write+0x153/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff8880241c4000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2480 bytes inside of
8192-byte region [ffff8880241c4000, ffff8880241c6000)
The buggy address belongs to the page:
page:ffffea0000907000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x241c0
head:ffffea0000907000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888016c42280
raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
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 1, ts 11641133143, 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_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
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]
kmem_cache_alloc_trace+0xf9/0x290 mm/slub.c:3250
kmalloc include/linux/slab.h:607 [inline]
kzalloc include/linux/slab.h:738 [inline]
init+0x68e/0x1170 drivers/usb/gadget/udc/dummy_hcd.c:2820
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
page_owner free stack trace missing

Memory state around the buggy address:
ffff8880241c4880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880241c4900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880241c4980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880241c4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880241c4a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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If you want to undo deduplication, reply with:
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[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=135e3632580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=1484f025181dd5c22443

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/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+1484f0...@syzkaller.appspotmail.com

vhci_hcd: release socket

vhci_hcd: disconnect device
vhci_hcd: stop threads
==================================================================
BUG: KASAN: use-after-free in vhci_shutdown_connection+0x211/0x580 drivers/usb/usbip/vhci_hcd.c:1057

Read of size 8 at addr ffff8881457c5568 by task kworker/u4:1/11

CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026

Workqueue: usbip_event event_handler
Call Trace:
<TASK>

dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
print_address_description mm/kasan/report.c:316 [inline]
print_report+0xa8/0x210 mm/kasan/report.c:420
kasan_report+0x10b/0x140 mm/kasan/report.c:524

vhci_shutdown_connection+0x211/0x580 drivers/usb/usbip/vhci_hcd.c:1057
event_handler+0x299/0x460 drivers/usb/usbip/usbip_event.c:79

process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

</TASK>

Allocated by task 1:

kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slab_common.c:936 [inline]
__kmalloc+0xb3/0x240 mm/slab_common.c:949
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]
__usb_create_hcd+0x5f/0x830 drivers/usb/core/hcd.c:2581
vhci_hcd_probe+0xff/0x370 drivers/usb/usbip/vhci_hcd.c:1376
platform_probe+0x137/0x1c0 drivers/base/platform.c:1400
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x24a/0xb40 drivers/base/dd.c:638
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a7/0x480 drivers/base/dd.c:1034
bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
device_add+0xbcf/0x1050 drivers/base/core.c:3712
platform_device_add+0x4bf/0x830 drivers/base/platform.c:717
vhci_hcd_init+0x3c7/0x4f1 drivers/usb/usbip/vhci_hcd.c:1571
do_one_initcall+0x257/0x800 init/main.c:1309
do_initcall_level+0x13d/0x1ed init/main.c:1382
do_initcalls+0x4b/0x8a init/main.c:1398
kernel_init_freeable+0x401/0x5ab init/main.c:1637
kernel_init+0x19/0x1b0 init/main.c:1525
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Freed by task 5516:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x200 mm/slub.c:3700
vhci_hcd_remove+0xe0/0x100 drivers/usb/usbip/vhci_hcd.c:1434
platform_remove+0x92/0xe0 drivers/base/platform.c:1422
device_remove drivers/base/dd.c:547 [inline]
__device_release_driver drivers/base/dd.c:1279 [inline]
device_release_driver_internal+0x47d/0x7c0 drivers/base/dd.c:1305
unbind_store+0x2e2/0x300 drivers/base/bus.c:193
kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff8881457c4000

which belongs to the cache kmalloc-8k of size 8192

The buggy address is located 5480 bytes inside of
8192-byte region [ffff8881457c4000, ffff8881457c6000)

The buggy address belongs to the physical page:
page:ffffea000515f000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1457c0
head:ffffea000515f000 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000010200 0000000000000000 dead000000000122 ffff888017442280

raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
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 1, tgid 1 (swapper/0), ts 10107823546, free_ts 0
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560
prep_new_page mm/page_alloc.c:2567 [inline]
get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358
__alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115
alloc_slab_page+0x5d/0x180 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2d0 mm/slub.c:1997
___slab_alloc+0xbc5/0x1240 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
__kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398
kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:699 [inline]
dummy_hcd_init+0x68e/0x1167 drivers/usb/gadget/udc/dummy_hcd.c:2839
do_one_initcall+0x257/0x800 init/main.c:1309
do_initcall_level+0x13d/0x1ed init/main.c:1382
do_initcalls+0x4b/0x8a init/main.c:1398
kernel_init_freeable+0x401/0x5ab init/main.c:1637
kernel_init+0x19/0x1b0 init/main.c:1525
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

page_owner free stack trace missing

Memory state around the buggy address:

ffff8881457c5400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881457c5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881457c5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881457c5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881457c5600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=1625e5b9580000

kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=1484f025181dd5c22443
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=142c74c6580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9a6fe2a54d0f/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/742b23a1d931/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b3f257c16d2e/bzImage-fb28aa72.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/dba0f6ce72c8/mount_0.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=1335ee32580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1484f0...@syzkaller.appspotmail.com

vhci_hcd: stop threads
==================================================================
BUG: KASAN: use-after-free in vhci_shutdown_connection+0x211/0x580 drivers/usb/usbip/vhci_hcd.c:1057

Read of size 8 at addr ffff888028e88c08 by task kworker/u4:7/4440

CPU: 0 PID: 4440 Comm: kworker/u4:7 Not tainted syzkaller #0

Freed by task 4485:

kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x200 mm/slub.c:3700
vhci_hcd_remove+0xe0/0x100 drivers/usb/usbip/vhci_hcd.c:1434
platform_remove+0x92/0xe0 drivers/base/platform.c:1422
device_remove drivers/base/dd.c:547 [inline]
__device_release_driver drivers/base/dd.c:1279 [inline]
device_release_driver_internal+0x47d/0x7c0 drivers/base/dd.c:1305
unbind_store+0x2e2/0x300 drivers/base/bus.c:193
kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888028e88000

which belongs to the cache kmalloc-8k of size 8192

The buggy address is located 3080 bytes inside of
8192-byte region [ffff888028e88000, ffff888028e8a000)

The buggy address belongs to the physical page:

page:ffffea0000a3a200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28e88
head:ffffea0000a3a200 order:3 compound_mapcount:0 compound_pincount:0

flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)

raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888017442280

raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
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 1, tgid 1 (swapper/0), ts 15006361027, free_ts 0

set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560
prep_new_page mm/page_alloc.c:2567 [inline]
get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358
__alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658
alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115
alloc_slab_page+0x5d/0x180 mm/slub.c:1799
allocate_slab mm/slub.c:1944 [inline]
new_slab+0x87/0x2d0 mm/slub.c:1997
___slab_alloc+0xbc5/0x1240 mm/slub.c:3154
__slab_alloc mm/slub.c:3240 [inline]
slab_alloc_node mm/slub.c:3325 [inline]
__kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398

__do_kmalloc_node mm/slab_common.c:935 [inline]
__kmalloc+0xa3/0x240 mm/slab_common.c:949

kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]
__usb_create_hcd+0x5f/0x830 drivers/usb/core/hcd.c:2581
vhci_hcd_probe+0xff/0x370 drivers/usb/usbip/vhci_hcd.c:1376
platform_probe+0x137/0x1c0 drivers/base/platform.c:1400
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x24a/0xb40 drivers/base/dd.c:638
__driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962

page_owner free stack trace missing

Memory state around the buggy address:

ffff888028e88b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888028e88b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888028e88c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888028e88c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888028e88d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: fb28aa725e05 Linux 6.1.180
git tree: linux-6.1.y

console output: https://syzkaller.appspot.com/x/log.txt?x=1437ee32580000
kernel config: https://syzkaller.appspot.com/x/.config?x=872c04466179833f

dashboard link: https://syzkaller.appspot.com/bug?extid=1484f025181dd5c22443
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=121be5b9580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13538649580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d420eb944682/disk-fb28aa72.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/affae450ab23/vmlinux-fb28aa72.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9e6919ed519/Image-fb28aa72.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1484f0...@syzkaller.appspotmail.com

vhci_hcd: stop threads
==================================================================
BUG: KASAN: use-after-free in vhci_shutdown_connection+0x210/0x574 drivers/usb/usbip/vhci_hcd.c:1057
Read of size 8 at addr ffff0000d1f84758 by task kworker/u4:3/59

CPU: 1 PID: 59 Comm: kworker/u4:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
Workqueue: usbip_event event_handler
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+0xa8/0xfc mm/kasan/report.c:524
__asan_report_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351
vhci_shutdown_connection+0x210/0x574 drivers/usb/usbip/vhci_hcd.c:1057
event_handler+0x288/0x454 drivers/usb/usbip/usbip_event.c:79
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

Allocated by task 1:
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+0xd8/0x180 mm/slab_common.c:949

kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:699 [inline]

__usb_create_hcd+0x6c/0x740 drivers/usb/core/hcd.c:2581
usb_create_shared_hcd+0x40/0x54 drivers/usb/core/hcd.c:2657
vhci_hcd_probe+0x1a4/0x354 drivers/usb/usbip/vhci_hcd.c:1393
platform_probe+0x148/0x1c8 drivers/base/platform.c:1400
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x3a0/0xac4 drivers/base/dd.c:638
__driver_probe_device+0x1c8/0x368 drivers/base/dd.c:804
driver_probe_device+0x78/0x324 drivers/base/dd.c:834
__device_attach_driver+0x28c/0x4c0 drivers/base/dd.c:962
bus_for_each_drv+0x154/0x1e4 drivers/base/bus.c:429
__device_attach+0x2a4/0x3d8 drivers/base/dd.c:1034
device_initial_probe+0x24/0x34 drivers/base/dd.c:1083
bus_probe_device+0xbc/0x1c4 drivers/base/bus.c:489
device_add+0x93c/0xe4c drivers/base/core.c:3712
platform_device_add+0x3f8/0x6f4 drivers/base/platform.c:717
vhci_hcd_init+0x390/0x4b0 drivers/usb/usbip/vhci_hcd.c:1571
do_one_initcall+0x278/0x9f0 init/main.c:1309
do_initcall_level+0x158/0x214 init/main.c:1382
do_initcalls+0x58/0xac init/main.c:1398
do_basic_setup+0x8c/0xa0 init/main.c:1417
kernel_init_freeable+0x35c/0x4f0 init/main.c:1637
kernel_init+0x24/0x1d8 init/main.c:1525
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850

Freed by task 4495:
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4c/0x80 mm/kasan/common.c:53
kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516
____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237
__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
hcd_release drivers/usb/core/hcd.c:2707 [inline]
kref_put include/linux/kref.h:65 [inline]
usb_put_hcd+0x124/0x16c drivers/usb/core/hcd.c:2721
vhci_hcd_remove+0x98/0x100 drivers/usb/usbip/vhci_hcd.c:1431
platform_remove+0x98/0xf0 drivers/base/platform.c:1422

device_remove drivers/base/dd.c:547 [inline]
__device_release_driver drivers/base/dd.c:1279 [inline]

device_release_driver_internal+0x3d4/0x6e4 drivers/base/dd.c:1305
device_driver_detach+0x48/0x58 drivers/base/dd.c:1341
unbind_store+0x2a8/0x2b4 drivers/base/bus.c:193
drv_attr_store+0x80/0xa4 drivers/base/bus.c:77
sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140
kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352

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

The buggy address belongs to the object at ffff0000d1f84000

which belongs to the cache kmalloc-8k of size 8192

The buggy address is located 1880 bytes inside of
8192-byte region [ffff0000d1f84000, ffff0000d1f86000)

The buggy address belongs to the physical page:

page:0000000026407423 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111f80
head:0000000026407423 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 dead000000000122 ffff0000c0002c00

raw: 0000000000000000 0000000000020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff0000d1f84600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff0000d1f84680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000d1f84700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff0000d1f84780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff0000d1f84800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================