Hello, syzbot found the following issue on: HEAD commit: 9852d85ec9d4 Linux 6.12-rc1 git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing console output: https://syzkaller.appspot.com/x/log.txt?x=159d5527980000 kernel config: https://syzkaller.appspot.com/x/.config?x=4510af5d637450fb dashboard link: https://syzkaller.appspot.com/bug?extid=65e7f3352b7346273644 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/d44acbbed8bd/disk-9852d85e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8e54c80139e6/vmlinux-9852d85e.xz kernel image: https://storage.googleapis.com/syzbot-assets/35f22e8643ee/bzImage-9852d85e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+65e7f3352b7346273644@xxxxxxxxxxxxxxxxxxxxxxxxx pwc: recv_control_msg error -71 req 04 val 1100 pwc: recv_control_msg error -71 req 04 val 1200 ================================================================== BUG: KASAN: slab-use-after-free in get_index drivers/media/v4l2-core/v4l2-dev.c:512 [inline] BUG: KASAN: slab-use-after-free in __video_register_device+0x4a2d/0x5aa0 drivers/media/v4l2-core/v4l2-dev.c:1028 Read of size 8 at addr ffff88811258c720 by task kworker/1:4/4947 CPU: 1 UID: 0 PID: 4947 Comm: kworker/1:4 Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 get_index drivers/media/v4l2-core/v4l2-dev.c:512 [inline] __video_register_device+0x4a2d/0x5aa0 drivers/media/v4l2-core/v4l2-dev.c:1028 video_register_device include/media/v4l2-dev.h:383 [inline] usb_pwc_probe+0xc69/0x1d40 drivers/media/usb/pwc/pwc-if.c:1123 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534 device_add+0x114b/0x1a70 drivers/base/core.c:3675 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294 call_driver_probe drivers/base/dd.c:579 [inline] really_probe+0x23e/0xa90 drivers/base/dd.c:658 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:459 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1030 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:534 device_add+0x114b/0x1a70 drivers/base/core.c:3675 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651 hub_port_connect drivers/usb/core/hub.c:5521 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x2e58/0x4f40 drivers/usb/core/hub.c:5903 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 2511: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] em28xx_v4l2_init+0x114/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2534 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 2511: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x37/0x50 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:2343 [inline] slab_free mm/slub.c:4580 [inline] kfree+0x130/0x480 mm/slub.c:4728 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x22a4/0x4050 drivers/media/usb/em28xx/em28xx-video.c:2903 em28xx_init_extension+0x137/0x200 drivers/media/usb/em28xx/em28xx-core.c:1117 request_module_async+0x61/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3457 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff88811258c000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1824 bytes inside of freed 8192-byte region [ffff88811258c000, ffff88811258e000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112588 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042280 ffffea0004856c00 dead000000000004 raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 0200000000000040 ffff888100042280 ffffea0004856c00 dead000000000004 head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000 head: 0200000000000003 ffffea0004496201 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 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 4999, tgid 4999 (kworker/1:5), ts 478011086957, free_ts 477789466413 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0xd5c/0x2630 mm/page_alloc.c:3457 __alloc_pages_noprof+0x221/0x22a0 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0xeb/0x400 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2413 [inline] allocate_slab mm/slub.c:2579 [inline] new_slab+0x2ba/0x3f0 mm/slub.c:2632 ___slab_alloc+0xd45/0x1760 mm/slub.c:3819 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3909 __slab_alloc_node mm/slub.c:3962 [inline] slab_alloc_node mm/slub.c:4123 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_noprof+0x325/0x3c0 mm/slub.c:4277 kmalloc_noprof include/linux/slab.h:882 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] usb_get_configuration+0x122/0x5e50 drivers/usb/core/config.c:894 usb_enumerate_device drivers/usb/core/hub.c:2483 [inline] usb_new_device+0x1189/0x1a10 drivers/usb/core/hub.c:2621 --- 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 syzkaller@xxxxxxxxxxxxxxxx. 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
