Re: [syzbot] [usb?] [media?] WARNING in usb_free_urb

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: invalid-free in usb_free_urb

smsmdtv:smscore_sendrequest_and_wait: sendrequest returned error -22
smsmdtv:smscore_set_device_mode: mode detect failed -22
smsmdtv:smscore_start_device: set device mode failed , rc -22
smsusb:smsusb_init_device: smscore_start_device(...) failed
==================================================================
BUG: KASAN: double-free in urb_destroy drivers/usb/core/urb.c:25 [inline]
BUG: KASAN: double-free in kref_put include/linux/kref.h:65 [inline]
BUG: KASAN: double-free in usb_free_urb+0xd0/0x120 drivers/usb/core/urb.c:96
Free of addr ffff888031560000 by task kworker/0:3/5873

CPU: 0 UID: 0 PID: 5873 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557
 check_slab_allocation mm/kasan/common.c:-1 [inline]
 __kasan_slab_pre_free+0x104/0x120 mm/kasan/common.c:261
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2634 [inline]
 slab_free mm/slub.c:6246 [inline]
 kfree+0x173/0x640 mm/slub.c:6561
 urb_destroy drivers/usb/core/urb.c:25 [inline]
 kref_put include/linux/kref.h:65 [inline]
 usb_free_urb+0xd0/0x120 drivers/usb/core/urb.c:96
 smsusb_term_device+0x1d7/0x3e0 drivers/media/usb/siano/smsusb.c:352
 smsusb_init_device drivers/media/usb/siano/smsusb.c:497 [inline]
 smsusb_probe+0x1aba/0x2280 drivers/media/usb/siano/smsusb.c:575
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1136
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7b6/0xb70 drivers/base/core.c:3691
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2266
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1136
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7b6/0xb70 drivers/base/core.c:3691
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5873:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5295 [inline]
 __kmalloc_noprof+0x35c/0x760 mm/slub.c:5307
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 smscore_create_usb_buffer drivers/media/common/siano/smscoreapi.c:622 [inline]
 smscore_register_device+0x721/0x12b0 drivers/media/common/siano/smscoreapi.c:724
 smsusb_init_device drivers/media/usb/siano/smsusb.c:458 [inline]
 smsusb_probe+0x13f7/0x2280 drivers/media/usb/siano/smsusb.c:575
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1136
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7b6/0xb70 drivers/base/core.c:3691
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2266
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1136
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7b6/0xb70 drivers/base/core.c:3691
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 5873:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6561
 smscore_unregister_device+0x33e/0x7e0 drivers/media/common/siano/smscoreapi.c:1228
 smsusb_term_device+0x1a7/0x3e0 drivers/media/usb/siano/smsusb.c:349
 smsusb_init_device drivers/media/usb/siano/smsusb.c:497 [inline]
 smsusb_probe+0x1aba/0x2280 drivers/media/usb/siano/smsusb.c:575
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1136
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7b6/0xb70 drivers/base/core.c:3691
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2266
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1136
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613
 device_add+0x7b6/0xb70 drivers/base/core.c:3691
 usb_new_device+0xa08/0x16f0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888031560000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 0 bytes inside of
 8192-byte region [ffff888031560000, ffff888031562000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888031564000 pfn:0x31560
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff88813fe30280 ffffea0001e6ac10 ffff88813fe2aac8
raw: ffff888031564000 0000000800020001 00000000f5000000 0000000000000000
head: 00fff00000000240 ffff88813fe30280 ffffea0001e6ac10 ffff88813fe2aac8
head: ffff888031564000 0000000800020001 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5873, tgid 5873 (kworker/0:3), ts 124014915400, free_ts 123135935773
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1860
 prep_new_page mm/page_alloc.c:1868 [inline]
 get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3948
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5228
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x339/0x3d0 mm/slub.c:7251
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __do_kmalloc_node mm/slub.c:5294 [inline]
 __kmalloc_noprof+0x474/0x760 mm/slub.c:5307
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 smscore_create_usb_buffer drivers/media/common/siano/smscoreapi.c:622 [inline]
 smscore_register_device+0x721/0x12b0 drivers/media/common/siano/smscoreapi.c:724
 smsusb_init_device drivers/media/usb/siano/smsusb.c:458 [inline]
 smsusb_probe+0x13f7/0x2280 drivers/media/usb/siano/smsusb.c:575
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:709
 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:851
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:881
 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1009
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c5/0x450 drivers/base/dd.c:1081
page last free pid 6478 tgid 6478 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1404 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2945
 __slab_free+0x274/0x2c0 mm/slub.c:5608
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4905
 vm_area_alloc+0x24/0x140 mm/vma_init.c:32
 __mmap_new_vma mm/vma.c:2547 [inline]
 __mmap_region mm/vma.c:2771 [inline]
 mmap_region+0x11cd/0x2280 mm/vma.c:2856
 do_mmap+0xc39/0x10c0 mm/mmap.c:560
 vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
 ksys_mmap_pgoff+0x51e/0x760 mm/mmap.c:606
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88803155ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88803155ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888031560000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888031560080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888031560100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         43cfbdda Merge tag 'for-linus-iommufd' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17169a6a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8195c5b22e79c2cf
dashboard link: https://syzkaller.appspot.com/bug?extid=b466336413a1fba398a5
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15f641ba580000