================================================================== BUG: KASAN: use-after-free in v4l2_fh_init+0x279/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 Read of size 8 at addr ffff88811b2ba8a0 by task v4l_id/14106 CPU: 0 PID: 14106 Comm: v4l_id Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 v4l2_fh_init+0x279/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 v4l2_fh_open+0x88/0xc0 drivers/media/v4l2-core/v4l2-fh.c:63 v4l_stk_open+0x12e/0x280 drivers/media/usb/stkwebcam/stk-webcam.c:626 v4l2_open+0x21c/0x3f0 drivers/media/v4l2-core/v4l2-dev.c:423 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b4/0x1090 fs/open.c:817 do_open fs/namei.c:3252 [inline] path_openat+0x1bdc/0x27a0 fs/namei.c:3369 do_filp_open+0x17e/0x3c0 fs/namei.c:3396 do_sys_openat2+0x16d/0x420 fs/open.c:1172 do_sys_open fs/open.c:1188 [inline] __do_sys_open fs/open.c:1196 [inline] __se_sys_open fs/open.c:1192 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1192 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4bae72a840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffef8f7a9c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffef8f7ab38 RCX: 00007f4bae72a840 RDX: 00007f4bae716ea0 RSI: 0000000000000000 RDI: 00007ffef8f7af23 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 00005583b4ad48d0 R13: 00007ffef8f7ab30 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:682 [inline] stk_camera_probe+0x7d/0xc50 drivers/media/usb/stkwebcam/stk-webcam.c:1281 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396 really_probe+0x2b1/0xe40 drivers/base/dd.c:561 driver_probe_device+0x285/0x3f0 drivers/base/dd.c:745 __device_attach_driver+0x216/0x2d0 drivers/base/dd.c:851 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4c0 drivers/base/dd.c:919 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbc4/0x1d90 drivers/base/core.c:3091 usb_set_configuration+0x113c/0x1910 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238 usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293 really_probe+0x2b1/0xe40 drivers/base/dd.c:561 driver_probe_device+0x285/0x3f0 drivers/base/dd.c:745 __device_attach_driver+0x216/0x2d0 drivers/base/dd.c:851 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4c0 drivers/base/dd.c:919 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbc4/0x1d90 drivers/base/core.c:3091 usb_new_device.cold+0x725/0x1057 drivers/usb/core/hub.c:2555 hub_port_connect drivers/usb/core/hub.c:5223 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x2348/0x42d0 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Freed by task 32: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:352 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kfree+0xdb/0x3a0 mm/slub.c:4122 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458 __device_release_driver+0x40d/0x740 drivers/base/dd.c:1161 device_release_driver_internal drivers/base/dd.c:1192 [inline] device_release_driver+0x26/0x40 drivers/base/dd.c:1215 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x502/0xd40 drivers/base/core.c:3270 usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1413 usb_disconnect.cold+0x27d/0x780 drivers/usb/core/hub.c:2218 hub_port_connect drivers/usb/core/hub.c:5074 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x1c8a/0x42d0 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 The buggy address belongs to the object at ffff88811b2ba000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2208 bytes inside of 4096-byte region [ffff88811b2ba000, ffff88811b2bb000) The buggy address belongs to the page: page:000000005e376328 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b2b8 head:000000005e376328 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 dead000000000100 dead000000000122 ffff888100042140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88811b2ba780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811b2ba800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811b2ba880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811b2ba900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811b2ba980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================