KASAN: use-after-free Read in usa49_glocont_callback

Status: upstream: reported syz repro on 2026/08/21 03:19
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+f5ea71f0017be0994aaa@syzkaller.appspotmail.com
First crash: 53d, last: 23d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/09/06 linux-6.1.y (ToT) cf82dcca9634 syz [report] KASAN: use-after-free Read in usa49_glocont_callback
2026/09/06 upstream (ToT) 9f0346dcbea3 syz Didn't crash
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: use-after-free Read in usa49_glocont_callback 19 syz, C 47 1d00h 69d 0/3 upstream: reported C repro on 2026/08/04 17:41
upstream KASAN: slab-use-after-free Read in usa49_glocont_callback prio:high actionable usb 19 C 7 18d 60d 24/29 upstream: reported C repro on 2026/08/14 01:30

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1045
Read of size 4 at addr ffff88801a6ff2b0 by task ksoftirqd/1/21

CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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
 usa49_glocont_callback+0x19f/0x270 drivers/usb/serial/keyspan.c:1045
 __usb_hcd_giveback_urb+0x35d/0x520 drivers/usb/core/hcd.c:1673
 dummy_timer+0xa39/0x34e0 drivers/usb/gadget/udc/dummy_hcd.c:2018
 __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
 __hrtimer_run_queues+0x522/0xc90 kernel/time/hrtimer.c:1815
 hrtimer_run_softirq+0x173/0x290 kernel/time/hrtimer.c:1832
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x667/0xa30 kernel/smpboot.c:164
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 4355:
 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]
 keyspan_port_probe+0xa7/0xd10 drivers/usb/serial/keyspan.c:2891
 usb_serial_device_probe+0xd6/0x2d0 drivers/usb/serial/bus.c:47
 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_serial_probe+0x2641/0x2c90 drivers/usb/serial/usb-serial.c:1153
 usb_probe_interface+0x5be/0xae0 drivers/usb/core/driver.c:396
 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_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+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 4387:
 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
 usb_serial_device_remove+0x11c/0x1e0 drivers/usb/serial/bus.c:97
 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
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3900
 usb_serial_disconnect+0x292/0x4c0 drivers/usb/serial/usb-serial.c:1201
 usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:549 [inline]
 __device_release_driver drivers/base/dd.c:1279 [inline]
 device_release_driver_internal+0x4cf/0x7c0 drivers/base/dd.c:1305
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3900
 usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
 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
 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

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 insert_work+0x54/0x3c0 kernel/workqueue.c:1361
 __queue_work+0xae2/0xee0 kernel/workqueue.c:1520
 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1548
 inet6addr_event+0x9c/0xc0 drivers/infiniband/core/roce_gid_mgmt.c:883
 notifier_call_chain kernel/notifier.c:87 [inline]
 atomic_notifier_call_chain+0x17a/0x2b0 kernel/notifier.c:225
 ipv6_add_addr+0xcd2/0xfc0 net/ipv6/addrconf.c:1181
 addrconf_add_linklocal+0x26f/0x6d0 net/ipv6/addrconf.c:3264
 addrconf_addr_gen+0x55e/0x6a0 net/ipv6/addrconf.c:3395
 addrconf_dev_config net/ipv6/addrconf.c:3440 [inline]
 addrconf_init_auto_addrs+0x6f7/0xaa0 net/ipv6/addrconf.c:3519
 addrconf_notify+0xacd/0xf60 net/ipv6/addrconf.c:3692
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
 netdev_state_change+0xe0/0x170 net/core/dev.c:1403
 linkwatch_do_dev+0x10d/0x160 net/core/link_watch.c:168
 __linkwatch_run_queue+0x410/0x660 net/core/link_watch.c:221
 linkwatch_event+0x48/0x50 net/core/link_watch.c:264
 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 ffff88801a6ff200
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 176 bytes inside of
 192-byte region [ffff88801a6ff200, ffff88801a6ff2c0)

The buggy address belongs to the physical page:
page:ffffea000069bfc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a6ff
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00015b2440 dead000000000002 ffff888017441a00
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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 2680687971, 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_node_track_caller+0xa0/0x240 mm/slab_common.c:956
 __do_krealloc mm/slab_common.c:1336 [inline]
 krealloc+0x6a/0x100 mm/slab_common.c:1369
 add_sysfs_param+0xe8/0x920 kernel/params.c:645
 kernel_add_sysfs_param+0xaf/0x11b kernel/params.c:798
 param_sysfs_builtin+0x20d/0x2ae kernel/params.c:837
 param_sysfs_init+0x66/0x6a kernel/params.c:958
 do_one_initcall+0x257/0x800 init/main.c:1309
 do_initcall_level+0x13d/0x1ed init/main.c:1382
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88801a6ff180: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801a6ff200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801a6ff280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                     ^
 ffff88801a6ff300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801a6ff380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/21 09:57 linux-6.1.y 7e6e67054721 1e72964b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in usa49_glocont_callback
2026/09/20 01:41 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in usa49_glocont_callback
2026/09/20 01:38 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in usa49_glocont_callback
2026/09/14 22:45 linux-6.1.y 1a8763b93150 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in usa49_glocont_callback
2026/08/21 03:18 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: use-after-free Read in usa49_glocont_callback
* Struck through repros no longer work on HEAD.