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

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syzbot

unread,
Jul 26, 2026, 3:02:29 AMJul 26
to syzkaller...@googlegroups.com
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=14de46b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=0e1162200a0f6516ee37
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+0e1162...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in interface_to_usbdev include/linux/usb.h:719 [inline]
BUG: KASAN: use-after-free in uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
Read of size 8 at addr ffff88807e1bd070 by task kworker/0:3/1326

CPU: 0 PID: 1326 Comm: kworker/0:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events request_firmware_work_func
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
interface_to_usbdev include/linux/usb.h:719 [inline]
uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
request_firmware_work_func+0xe8/0x1a0 drivers/base/firmware_loader/main.c:1129
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 4758:
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]
usb_set_configuration+0x3b6/0x2030 drivers/usb/core/message.c:2051
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 4758:
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
device_release+0x92/0x1c0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:713 [inline]
kobject_release lib/kobject.c:744 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x217/0x450 lib/kobject.c:761
usb_disable_device+0x612/0x8a0 drivers/usb/core/message.c:1479
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
process_scheduled_works kernel/workqueue.c:2373 [inline]
worker_thread+0xd93/0x12a0 kernel/workqueue.c:2459
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff88807e1bd000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 112 bytes inside of
2048-byte region [ffff88807e1bd000, ffff88807e1bd800)
The buggy address belongs to the page:
page:ffffea0001f86e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e1b8
head:ffffea0001f86e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888016c42000
raw: 0000000000000000 0000000000080008 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 4192, ts 61124964605, free_ts 60497468319
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_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]
__kmalloc_track_caller+0x11b/0x330 mm/slub.c:4930
kmemdup+0x22/0x50 mm/util.c:128
neigh_sysctl_register+0xab/0xa90 net/core/neighbour.c:3652
devinet_sysctl_register+0xa8/0x1f0 net/ipv4/devinet.c:2640
inetdev_init+0x28c/0x4d0 net/ipv4/devinet.c:277
inetdev_event+0x26f/0x1350 net/ipv4/devinet.c:1543
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]
register_netdevice+0x12a8/0x1720 net/core/dev.c:10454
veth_newlink+0x6af/0xe20 drivers/net/veth.c:1685
__rtnl_newlink net/core/rtnetlink.c:3538 [inline]
rtnl_newlink+0x139e/0x1920 net/core/rtnetlink.c:3586
rtnetlink_rcv_msg+0x7f1/0xf10 net/core/rtnetlink.c:5698
netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2519
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
put_page include/linux/mm.h:1258 [inline]
__skb_frag_unref include/linux/skbuff.h:3254 [inline]
skb_release_data+0x35c/0x830 net/core/skbuff.c:672
skb_release_all net/core/skbuff.c:742 [inline]
__kfree_skb+0x4c/0x60 net/core/skbuff.c:756
sk_eat_skb include/net/sock.h:2793 [inline]
tcp_recvmsg_locked+0x143d/0x2690 net/ipv4/tcp.c:2520
tcp_recvmsg+0x22a/0x760 net/ipv4/tcp.c:2566
inet_recvmsg+0x146/0x200 net/ipv4/af_inet.c:868
sock_recvmsg_nosec net/socket.c:969 [inline]
sock_recvmsg net/socket.c:987 [inline]
sock_read_iter+0x2c2/0x380 net/socket.c:1068
call_read_iter include/linux/fs.h:2167 [inline]
new_sync_read fs/read_write.c:404 [inline]
vfs_read+0x75e/0xd50 fs/read_write.c:485
ksys_read+0x153/0x260 fs/read_write.c:623
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

Memory state around the buggy address:
ffff88807e1bcf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807e1bcf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88807e1bd000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807e1bd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807e1bd100: 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.
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syzbot

unread,
Jul 26, 2026, 4:23:32 AMJul 26
to syzkaller...@googlegroups.com
Hello,

syzbot found the following issue on:

HEAD commit: dc5c83b7f5f8 Linux 6.1.178
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=167aa232580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=0e53be52403a77f1cf74
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/a9aa438e39c2/disk-dc5c83b7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a7b5afd2e170/vmlinux-dc5c83b7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c7673d370fb/bzImage-dc5c83b7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0e53be...@syzkaller.appspotmail.com

kobject_add_internal failed for firmware (error: -2 parent: 2-1)
firmware ueagle-atm!eagleII.fw: fw_load_sysfs_fallback: device_register failed
==================================================================
BUG: KASAN: use-after-free in interface_to_usbdev include/linux/usb.h:721 [inline]
BUG: KASAN: use-after-free in uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
Read of size 8 at addr ffff888026f3a070 by task kworker/1:16/4960

CPU: 1 PID: 4960 Comm: kworker/1:16 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events request_firmware_work_func
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
interface_to_usbdev include/linux/usb.h:721 [inline]
uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
request_firmware_work_func+0xe8/0x1a0 drivers/base/firmware_loader/main.c:1137
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 4963:
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
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:699 [inline]
usb_set_configuration+0x3b6/0x2030 drivers/usb/core/message.c:2051
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+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
usb_new_device+0xa01/0x15e0 drivers/usb/core/hub.c:2659
hub_port_connect drivers/usb/core/hub.c:5517 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x2b2f/0x5200 drivers/usb/core/hub.c:5899
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

Freed by task 4963:
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
device_release+0x92/0x1c0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:681 [inline]
kobject_release lib/kobject.c:712 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x217/0x450 lib/kobject.c:729
usb_disable_device+0x612/0x8a0 drivers/usb/core/message.c:1479
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2314
hub_port_connect drivers/usb/core/hub.c:5361 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x1d27/0x5200 drivers/usb/core/hub.c:5899
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
process_scheduled_works kernel/workqueue.c:2355 [inline]
worker_thread+0xd6e/0x12a0 kernel/workqueue.c:2441
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888026f3a000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 112 bytes inside of
2048-byte region [ffff888026f3a000, ffff888026f3a800)

The buggy address belongs to the physical page:
page:ffffea00009bce00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26f38
head:ffffea00009bce00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017442000
raw: 0000000000000000 0000000000080008 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4278, tgid 4278 (syz-executor), ts 71317040098, free_ts 71238820213
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_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_node_track_caller+0xa0/0x240 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
pskb_expand_head+0x1c0/0x13a0 net/core/skbuff.c:1849
netlink_trim+0x180/0x220 net/netlink/af_netlink.c:1299
netlink_broadcast+0x66/0x10f0 net/netlink/af_netlink.c:1505
nlmsg_multicast include/net/netlink.h:1078 [inline]
nlmsg_notify+0xe3/0x1a0 net/netlink/af_netlink.c:2559
dev_open+0xe9/0x190 net/core/dev.c:1541
bond_enslave+0xe41/0x3820 drivers/net/bonding/bond_main.c:2042
do_set_master net/core/rtnetlink.c:2642 [inline]
do_setlink+0xd66/0x29c0 net/core/rtnetlink.c:2852
__rtnl_newlink net/core/rtnetlink.c:3622 [inline]
rtnl_newlink+0x16e4/0x1f90 net/core/rtnetlink.c:3669
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1487 [inline]
free_pcp_prepare mm/page_alloc.c:1537 [inline]
free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509
free_slab mm/slub.c:2036 [inline]
discard_slab mm/slub.c:2042 [inline]
__unfreeze_partials+0x188/0x1e0 mm/slub.c:2591
put_cpu_partial+0x17c/0x250 mm/slub.c:2667
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737
slab_alloc_node mm/slub.c:3359 [inline]
__kmem_cache_alloc_node+0x19d/0x270 mm/slub.c:3398
kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
kmalloc include/linux/slab.h:563 [inline]
netdev_name_node_alloc net/core/dev.c:259 [inline]
netdev_name_node_head_alloc net/core/dev.c:273 [inline]
register_netdevice+0x555/0x1b80 net/core/dev.c:10163
veth_newlink+0x8be/0xd60 drivers/net/veth.c:1758
rtnl_newlink_create net/core/rtnetlink.c:3436 [inline]
__rtnl_newlink net/core/rtnetlink.c:3656 [inline]
rtnl_newlink+0x14b3/0x1f90 net/core/rtnetlink.c:3669
rtnetlink_rcv_msg+0x863/0xfb0 net/core/rtnetlink.c:6166
netlink_rcv_skb+0x1ef/0x440 net/netlink/af_netlink.c:2516
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344

Memory state around the buggy address:
ffff888026f39f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888026f39f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888026f3a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888026f3a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888026f3a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

syzbot

unread,
Jul 26, 2026, 5:19:37 AMJul 26
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:

HEAD commit: dc5c83b7f5f8 Linux 6.1.178
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=111566b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31dfefc4a14efea3
dashboard link: https://syzkaller.appspot.com/bug?extid=0e53be52403a77f1cf74
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=123472ea580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1131a449580000
==================================================================
BUG: KASAN: use-after-free in interface_to_usbdev include/linux/usb.h:721 [inline]
BUG: KASAN: use-after-free in uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
Read of size 8 at addr ffff88801d75d070 by task kworker/1:10/4427

CPU: 1 PID: 4427 Comm: kworker/1:10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events request_firmware_work_func
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
interface_to_usbdev include/linux/usb.h:721 [inline]
uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
request_firmware_work_func+0xe8/0x1a0 drivers/base/firmware_loader/main.c:1137
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 4425:
Freed by task 4425:
The buggy address belongs to the object at ffff88801d75d000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 112 bytes inside of
2048-byte region [ffff88801d75d000, ffff88801d75d800)

The buggy address belongs to the physical page:
page:ffffea000075d600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d758
head:ffffea000075d600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888017442000
raw: 0000000000000000 0000000000080008 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4348, tgid 4348 (kworker/1:5), ts 83094680578, free_ts 82986659123
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_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_node_track_caller+0xa0/0x240 mm/slab_common.c:956
kmalloc_reserve net/core/skbuff.c:446 [inline]
__alloc_skb+0x226/0x7d0 net/core/skbuff.c:515
alloc_skb include/linux/skbuff.h:1303 [inline]
mld_newpack+0x12d/0xc10 net/ipv6/mcast.c:1773
add_grhead net/ipv6/mcast.c:1884 [inline]
add_grec+0x1466/0x19c0 net/ipv6/mcast.c:2023
mld_send_initial_cr+0x148/0x2d0 net/ipv6/mcast.c:2268
ipv6_mc_dad_complete+0x80/0x180 net/ipv6/mcast.c:2279
addrconf_dad_completed+0x7bb/0xd90 net/ipv6/addrconf.c:4283
addrconf_dad_work+0xc68/0x1500 net/ipv6/addrconf.c:-1
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1487 [inline]
free_pcp_prepare mm/page_alloc.c:1537 [inline]
free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414
free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509
qlink_free mm/kasan/quarantine.c:168 [inline]
qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187
kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294
__kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737
slab_alloc_node mm/slub.c:3359 [inline]
__kmem_cache_alloc_node+0x19d/0x270 mm/slub.c:3398
kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026
kmalloc include/linux/slab.h:563 [inline]
gro_cells_destroy+0x328/0x400 net/core/gro_cells.c:125
ip_tunnel_dev_free+0x15/0x50 net/ipv4/ip_tunnel.c:1044
netdev_run_todo+0xbe3/0xdb0 net/core/dev.c:10552
ip_tunnel_delete_nets+0x32b/0x370 net/ipv4/ip_tunnel.c:1158
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x78e/0xba0 net/core/net_namespace.c:640
process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376

Memory state around the buggy address:
ffff88801d75cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801d75cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801d75d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801d75d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801d75d100: 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

unread,
Jul 26, 2026, 7:55:25 AMJul 26
to syzkaller...@googlegroups.com
syzbot has found a reproducer for 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=13cc11b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=0e1162200a0f6516ee37
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=115a388e580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=139e3fde580000

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+0e1162...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in interface_to_usbdev include/linux/usb.h:719 [inline]
BUG: KASAN: use-after-free in uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
Read of size 8 at addr ffff888028fca070 by task kworker/1:20/4280

CPU: 1 PID: 4280 Comm: kworker/1:20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: events request_firmware_work_func
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
interface_to_usbdev include/linux/usb.h:719 [inline]
uea_upload_pre_firmware+0x89/0x7c0 drivers/usb/atm/ueagle-atm.c:603
request_firmware_work_func+0xe8/0x1a0 drivers/base/firmware_loader/main.c:1129
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 4279:
Freed by task 4279:
The buggy address belongs to the object at ffff888028fca000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 112 bytes inside of
2048-byte region [ffff888028fca000, ffff888028fca800)
The buggy address belongs to the page:
page:ffffea0000a3f200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28fc8
head:ffffea0000a3f200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888016c42000
raw: 0000000000000000 0000000000080008 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4280, ts 86702575519, free_ts 86572922412
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_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]
__kmalloc_node_track_caller+0x13d/0x3a0 mm/slub.c:4963
kmalloc_reserve net/core/skbuff.c:356 [inline]
__alloc_skb+0x22c/0x750 net/core/skbuff.c:427
alloc_skb include/linux/skbuff.h:1162 [inline]
mld_newpack+0x12f/0xba0 net/ipv6/mcast.c:1773
add_grhead net/ipv6/mcast.c:1884 [inline]
add_grec+0x1364/0x1840 net/ipv6/mcast.c:2023
mld_send_initial_cr+0x288/0x540 net/ipv6/mcast.c:2268
ipv6_mc_dad_complete+0x83/0x410 net/ipv6/mcast.c:2279
addrconf_dad_completed+0x673/0xc80 net/ipv6/addrconf.c:4265
addrconf_dad_work+0xc83/0x1530 net/ipv6/addrconf.c:-1
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
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1340 [inline]
free_pcp_prepare mm/page_alloc.c:1391 [inline]
free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
free_slab mm/slub.c:2020 [inline]
discard_slab mm/slub.c:2026 [inline]
__unfreeze_partials+0x188/0x1e0 mm/slub.c:2512
put_cpu_partial+0x12d/0x190 mm/slub.c:2592
qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
__kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3225 [inline]
slab_alloc mm/slub.c:3233 [inline]
__kmalloc_track_caller+0x187/0x330 mm/slub.c:4930
memdup_user+0x22/0xb0 mm/util.c:173
raw_alloc_io_data drivers/usb/gadget/legacy/raw_gadget.c:627 [inline]
raw_ioctl_ep0_write drivers/usb/gadget/legacy/raw_gadget.c:718 [inline]
raw_ioctl+0x1d1e/0x3750 drivers/usb/gadget/legacy/raw_gadget.c:1262
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
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

Memory state around the buggy address:
ffff888028fc9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888028fc9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888028fca000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888028fca080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888028fca100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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