================================================================== 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 ffff88804aee8738 by task v4l_id/4042 CPU: 1 PID: 4042 Comm: v4l_id Not tainted 6.1.0-rc2-syzkaller-15030-ga970174d7a10 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x461 mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 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:2153 v4l2_open+0x21c/0x3f0 drivers/media/v4l2-core/v4l2-dev.c:427 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x1bf6/0x2860 fs/namei.c:3713 do_filp_open+0x1b6/0x400 fs/namei.c:3740 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fcdc5d25697 Code: 25 00 00 41 00 3d 00 00 41 00 74 37 64 8b 04 25 18 00 00 00 85 c0 75 5b 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 85 00 00 00 48 83 c4 68 5d 41 5c c3 0f 1f RSP: 002b:00007ffe5c845770 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000055852a7c0c40 RCX: 00007fcdc5d25697 RDX: 0000000000000000 RSI: 00007ffe5c845f1f RDI: 00000000ffffff9c RBP: 00007ffe5c845f1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3701: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0x9f/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:576 [inline] kzalloc include/linux/slab.h:712 [inline] em28xx_v4l2_init drivers/media/usb/em28xx/em28xx-video.c:2532 [inline] em28xx_v4l2_init.cold+0x93/0x325c drivers/media/usb/em28xx/em28xx-video.c:2510 em28xx_init_extension+0x12f/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x5d/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 process_scheduled_works kernel/workqueue.c:2352 [inline] worker_thread+0x803/0x1080 kernel/workqueue.c:2441 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Freed by task 3701: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:177 [inline] __cache_free mm/slab.c:3389 [inline] __do_kmem_cache_free mm/slab.c:3585 [inline] __kmem_cache_free+0xc9/0x3a0 mm/slab.c:3592 kref_put.isra.0+0x6f/0xa0 include/linux/kref.h:65 em28xx_v4l2_init drivers/media/usb/em28xx/em28xx-video.c:2901 [inline] em28xx_v4l2_init.cold+0x263/0x325c drivers/media/usb/em28xx/em28xx-video.c:2510 em28xx_init_extension+0x12f/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1116 request_module_async+0x5d/0x70 drivers/media/usb/em28xx/em28xx-cards.c:3405 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 process_scheduled_works kernel/workqueue.c:2352 [inline] worker_thread+0x803/0x1080 kernel/workqueue.c:2441 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff88804aee8000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1848 bytes inside of 8192-byte region [ffff88804aee8000, ffff88804aeea000) The buggy address belongs to the physical page: page:ffffea00012bba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4aee8 head:ffffea00012bba00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 ffffea00012bbb08 ffff888040000b50 ffff888011840a00 raw: 0000000000000000 ffff88804aee8000 0000000100000001 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 0x1d28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3964, tgid 3964 (syz-executor.1), ts 118938842378, free_ts 0 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5554 __alloc_pages_node include/linux/gfp.h:223 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2570 fallback_alloc+0x1e2/0x2d0 mm/slab.c:3113 __do_cache_alloc mm/slab.c:3217 [inline] slab_alloc_node mm/slab.c:3250 [inline] __kmem_cache_alloc_node+0x16c/0x500 mm/slab.c:3549 __do_kmalloc_node mm/slab_common.c:954 [inline] __kmalloc_node_track_caller+0x45/0xc0 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 [inline] __alloc_skb+0xd9/0x2f0 net/core/skbuff.c:509 alloc_skb include/linux/skbuff.h:1267 [inline] netlink_dump+0x2c0/0xc20 net/netlink/af_netlink.c:2242 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380 genl_family_rcv_msg_dumpit+0x1c9/0x310 net/netlink/genetlink.c:689 genl_family_rcv_msg net/netlink/genetlink.c:805 [inline] genl_rcv_msg+0x55d/0x780 net/netlink/genetlink.c:825 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2540 genl_rcv+0x24/0x40 net/netlink/genetlink.c:836 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 page_owner free stack trace missing Memory state around the buggy address: ffff88804aee8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804aee8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804aee8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804aee8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804aee8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================