================================================================== 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 ffff888016c088b8 by task v4l_id/8789 CPU: 1 PID: 8789 Comm: v4l_id Not tainted 5.13.0-rc5-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+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 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 em28xx_v4l2_open+0x11c/0x570 drivers/media/usb/em28xx/em28xx-video.c:2163 v4l2_open+0x21c/0x3f0 drivers/media/v4l2-core/v4l2-dev.c:429 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x11b0 fs/open.c:826 do_open fs/namei.c:3361 [inline] path_openat+0x1c0e/0x27e0 fs/namei.c:3494 do_filp_open+0x190/0x3d0 fs/namei.c:3521 do_sys_openat2+0x16d/0x420 fs/open.c:1187 do_sys_open fs/open.c:1203 [inline] __do_sys_open fs/open.c:1211 [inline] __se_sys_open fs/open.c:1207 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1207 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fcdb6680840 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:00007fffc3f9ab48 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fffc3f9acb8 RCX: 00007fcdb6680840 RDX: 00007fcdb666cea0 RSI: 0000000000000000 RDI: 00007fffc3f9af1e RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000b R11: 0000000000000246 R12: 000055603ea8a8d0 R13: 00007fffc3f9acb0 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea00005b0200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16c08 head:ffffea00005b0200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010000(head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 3168, ts 64084487186, free_ts 64038689685 prep_new_page mm/page_alloc.c:2358 [inline] get_page_from_freelist+0x1033/0x2b60 mm/page_alloc.c:3994 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5200 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272 kmalloc_order+0x34/0xf0 mm/slab_common.c:924 kmalloc_order_trace+0x14/0x130 mm/slab_common.c:940 kmalloc_large include/linux/slab.h:485 [inline] kmalloc include/linux/slab.h:549 [inline] kzalloc include/linux/slab.h:686 [inline] em28xx_usb_probe+0x1f7/0xd00 drivers/media/usb/em28xx/em28xx-cards.c:3855 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396 really_probe+0x291/0xf60 drivers/base/dd.c:576 driver_probe_device+0x298/0x410 drivers/base/dd.c:763 __device_attach_driver+0x203/0x2c0 drivers/base/dd.c:870 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431 __device_attach+0x228/0x4b0 drivers/base/dd.c:938 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0xbe0/0x2100 drivers/base/core.c:3324 usb_set_configuration+0x113f/0x1910 drivers/usb/core/message.c:2164 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1298 [inline] __free_pages_ok+0x476/0xce0 mm/page_alloc.c:1572 kref_put.isra.0+0x6f/0xa0 include/linux/kref.h:65 em28xx_v4l2_init drivers/media/usb/em28xx/em28xx-video.c:2911 [inline] em28xx_v4l2_init.cold+0x238/0x3265 drivers/media/usb/em28xx/em28xx-video.c:2520 em28xx_init_extension+0x12f/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1126 request_module_async+0x5d/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3410 process_one_work+0x98d/0x1600 kernel/workqueue.c:2276 worker_thread+0x64c/0x1120 kernel/workqueue.c:2422 kthread+0x3b1/0x4a0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Memory state around the buggy address: ffff888016c08780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888016c08800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888016c08880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888016c08900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888016c08980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================