================================================================== BUG: KASAN: use-after-free in dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:109 Read of size 8 at addr ffff888029de9218 by task syz.4.1063/9119 CPU: 1 PID: 9119 Comm: syz.4.1063 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:109 chrdev_open+0x5c5/0x6a0 fs/char_dev.c:414 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f15b545268e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f15b36c9b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f15b36ca6c0 RCX: 00007f15b545268e RDX: 0000000000000002 RSI: 00007f15b36c9c00 RDI: ffffffffffffff9c RBP: 00007f15b36c9c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f15b570b128 R14: 00007f15b570b090 R15: 00007ffdc892dff8 Allocated by task 7917: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:612 [inline] kzalloc include/linux/slab.h:738 [inline] fib_create_info+0xabc/0x24f0 net/ipv4/fib_semantics.c:1478 fib_table_insert+0xe4/0x1bb0 net/ipv4/fib_trie.c:1212 fib_magic+0x2e1/0x3c0 net/ipv4/fib_frontend.c:1106 fib_add_ifaddr+0x140/0x5e0 net/ipv4/fib_frontend.c:1128 fib_inetaddr_event+0x13c/0x1c0 net/ipv4/fib_frontend.c:1442 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 __inet_insert_ifa+0x9f7/0xbe0 net/ipv4/devinet.c:567 inet_rtm_newaddr+0x99a/0x1890 net/ipv4/devinet.c:966 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5687 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2072 __do_sys_sendto net/socket.c:2084 [inline] __se_sys_sendto net/socket.c:2080 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2080 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3011 [inline] call_rcu+0x189/0x950 kernel/rcu/tree.c:3091 free_fib_info net/ipv4/fib_semantics.c:255 [inline] fib_info_put include/net/ip_fib.h:579 [inline] fib_release_info+0x684/0x740 net/ipv4/fib_semantics.c:281 fib_table_delete+0xdf2/0x1000 net/ipv4/fib_trie.c:1747 fib_magic+0x301/0x3c0 net/ipv4/fib_frontend.c:1108 fib_del_ifaddr+0x1045/0x1440 net/ipv4/fib_frontend.c:1319 fib_inetaddr_event+0xb7/0x1c0 net/ipv4/fib_frontend.c:1450 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 __inet_del_ifa+0x879/0x1020 net/ipv4/devinet.c:442 inet_del_ifa net/ipv4/devinet.c:479 [inline] inetdev_destroy net/ipv4/devinet.c:320 [inline] inetdev_event+0x5b6/0x1370 net/ipv4/devinet.c:1611 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] unregister_netdevice_many+0x1049/0x19f0 net/core/dev.c:11160 default_device_exit_batch+0x364/0x3c0 net/core/dev.c:11693 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x791/0xba0 net/core/net_namespace.c:635 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff888029de9200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff888029de9200, ffff888029de9300) The buggy address belongs to the page: page:ffffea0000a77a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888029de9200 pfn:0x29de8 head:ffffea0000a77a00 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001ed9588 ffffea0001811588 ffff888016c41b40 raw: ffff888029de9200 000000000010000e 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, ts 18864831160, free_ts 0 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node+0x200/0x3b0 mm/slub.c:4456 kmalloc_node include/linux/slab.h:630 [inline] kvmalloc_node+0x84/0x130 mm/util.c:619 kvmalloc include/linux/mm.h:816 [inline] kvzalloc include/linux/mm.h:824 [inline] v4l2_ctrl_new+0x70f/0x1310 drivers/media/v4l2-core/v4l2-ctrls-core.c:1306 v4l2_ctrl_new_std+0x247/0x300 drivers/media/v4l2-core/v4l2-ctrls-core.c:1429 handler_new_ref+0x14a/0x950 drivers/media/v4l2-core/v4l2-ctrls-core.c:1098 v4l2_ctrl_add_handler+0x197/0x280 drivers/media/v4l2-core/v4l2-ctrls-core.c:1573 vivid_create_controls+0x2b0e/0x3460 drivers/media/test-drivers/vivid/vivid-ctrls.c:1928 vivid_create_instance drivers/media/test-drivers/vivid/vivid-core.c:1860 [inline] vivid_probe+0x3c47/0x67a0 drivers/media/test-drivers/vivid/vivid-core.c:2031 platform_probe+0x137/0x1c0 drivers/base/platform.c:1391 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 page_owner free stack trace missing Memory state around the buggy address: ffff888029de9100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888029de9180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888029de9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888029de9280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029de9300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================