================================================================== BUG: KASAN: slab-use-after-free in v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 Read of size 8 at addr ffff88802e670740 by task v4l_id/6183 CPU: 0 UID: 0 PID: 6183 Comm: v4l_id Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __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:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 v4l2_fh_init+0x27d/0x2c0 drivers/media/v4l2-core/v4l2-fh.c:25 v4l2_fh_open+0x64/0xa0 drivers/media/v4l2-core/v4l2-fh.c:64 em28xx_v4l2_open+0x24e/0x7e0 drivers/media/usb/em28xx/em28xx-video.c:2153 v4l2_open+0x1d2/0x5e0 drivers/media/v4l2-core/v4l2-dev.c:433 chrdev_open+0x234/0x6a0 fs/char_dev.c:414 do_dentry_open+0x748/0x1590 fs/open.c:962 vfs_open+0x82/0x3f0 fs/open.c:1094 do_open fs/namei.c:4637 [inline] path_openat+0x2078/0x3140 fs/namei.c:4796 do_filp_open+0x20b/0x470 fs/namei.c:4823 do_sys_openat2+0x121/0x290 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f53c7ea7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffe8ab03d00 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f53c866d880 RCX: 00007f53c7ea7407 RDX: 0000000000000000 RSI: 00007ffe8ab05f1c RDI: ffffffffffffff9c RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffe8ab03f50 R14: 00007f53c87d4000 R15: 000055902695e4d8 Allocated by task 59: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] em28xx_v4l2_init+0x114/0x4080 drivers/media/usb/em28xx/em28xx-video.c:2532 em28xx_init_extension+0x13a/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+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Freed by task 59: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6878 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2118 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x22b5/0x4080 drivers/media/usb/em28xx/em28xx-video.c:2901 em28xx_init_extension+0x13a/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+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 The buggy address belongs to the object at ffff88802e670000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 1856 bytes inside of freed 8192-byte region [ffff88802e670000, ffff88802e672000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2e670 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b443180 ffffea0000d41a00 0000000000000004 raw: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b443180 ffffea0000d41a00 0000000000000004 head: 0000000000000000 0000000080020002 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0000b99c01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5951, tgid 5951 (syz-executor), ts 67564950519, free_ts 66345626044 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5240 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x485/0x800 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] audit_log_d_path+0xed/0x200 kernel/audit.c:2193 audit_log_lsm_data+0xacf/0x1fe0 security/lsm_audit.c:212 dump_common_audit_data security/lsm_audit.c:421 [inline] common_lsm_audit+0x238/0x300 security/lsm_audit.c:451 slow_avc_audit+0x186/0x210 security/selinux/avc.c:779 avc_audit security/selinux/include/avc.h:131 [inline] avc_has_perm+0x1b5/0x1f0 security/selinux/avc.c:1198 inode_has_perm+0x166/0x1d0 security/selinux/hooks.c:1687 file_path_has_perm security/selinux/hooks.c:1737 [inline] selinux_file_open+0x39d/0x510 security/selinux/hooks.c:4163 security_file_open+0xa5/0x1e0 security/security.c:2636 page last free pid 5933 tgid 5928 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2973 __folio_put+0x329/0x450 mm/swap.c:112 folio_put include/linux/mm.h:1612 [inline] put_page include/linux/mm.h:1681 [inline] put_netmem net/core/skbuff.c:7419 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x81a/0x9e0 net/core/skbuff.c:1101 skb_release_all net/core/skbuff.c:1182 [inline] napi_consume_skb+0x20a/0x300 net/core/skbuff.c:1517 skb_defer_free_flush+0x1ec/0x280 net/core/dev.c:6809 net_rx_action+0x39f/0xfa0 net/core/dev.c:7877 handle_softirqs+0x219/0x950 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:510 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline] __dev_queue_xmit+0x797/0x46c0 net/core/dev.c:4859 dev_queue_xmit include/linux/netdevice.h:3381 [inline] neigh_hh_output include/net/neighbour.h:540 [inline] neigh_output include/net/neighbour.h:554 [inline] ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:237 __ip_finish_output.part.0+0x1b4/0x350 net/ipv4/ip_output.c:315 __ip_finish_output net/ipv4/ip_output.c:303 [inline] ip_finish_output net/ipv4/ip_output.c:325 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x35f/0xa90 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:464 [inline] ip_local_out net/ipv4/ip_output.c:131 [inline] __ip_queue_xmit+0x1bee/0x2330 net/ipv4/ip_output.c:534 __tcp_transmit_skb+0x2cae/0x48b0 net/ipv4/tcp_output.c:1631 __tcp_send_ack.part.0+0x4ca/0x910 net/ipv4/tcp_output.c:4464 Memory state around the buggy address: ffff88802e670600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802e670680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802e670700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802e670780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802e670800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================