================================================================== BUG: KASAN: use-after-free in dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:99 Read of size 8 at addr ffff888029396e18 by task syz.3.611/6680 CPU: 0 PID: 6680 Comm: syz.3.611 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x5c5/0x6a0 fs/char_dev.c:414 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd1beb5d68e 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:00007fd1bfaddb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fd1bfade6c0 RCX: 00007fd1beb5d68e RDX: 0000000000040002 RSI: 00007fd1bfaddc00 RDI: ffffffffffffff9c RBP: 00007fd1bfaddc00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fd1bee16128 R14: 00007fd1bee16090 R15: 00007ffd336aa728 Allocated by task 6572: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] new_dir fs/proc/proc_sysctl.c:973 [inline] get_subdir fs/proc/proc_sysctl.c:1017 [inline] __register_sysctl_table+0x96c/0xe70 fs/proc/proc_sysctl.c:1379 neigh_sysctl_register+0x9a2/0xa80 net/core/neighbour.c:3858 addrconf_sysctl_register+0xac/0x1b0 net/ipv6/addrconf.c:7193 ipv6_add_dev+0xbe0/0x1120 net/ipv6/addrconf.c:451 addrconf_notify+0x634/0xf40 net/ipv6/addrconf.c:3595 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] register_netdevice+0x163f/0x1b10 net/core/dev.c:10276 __vxlan_dev_create+0x2c9/0x770 drivers/net/vxlan/vxlan_core.c:3868 vxlan_newlink+0x11b/0x190 drivers/net/vxlan/vxlan_core.c:4234 rtnl_newlink_create net/core/rtnetlink.c:3427 [inline] __rtnl_newlink net/core/rtnetlink.c:3647 [inline] rtnl_newlink+0x151e/0x20a0 net/core/rtnetlink.c:3660 rtnetlink_rcv_msg+0x87c/0xfc0 net/core/rtnetlink.c:6157 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5be/0x970 net/socket.c:2518 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572 __sys_sendmsg net/socket.c:2601 [inline] __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 34: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free_bulk+0x348/0x460 mm/slub.c:3805 kfree_bulk include/linux/slab.h:475 [inline] kfree_rcu_work+0x33f/0x890 kernel/rcu/tree.c:3091 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x103/0x870 kernel/rcu/tree.c:3405 drop_sysctl_table+0x359/0x4e0 fs/proc/proc_sysctl.c:1731 drop_sysctl_table+0x348/0x4e0 fs/proc/proc_sysctl.c:1734 unregister_sysctl_table+0x85/0x130 fs/proc/proc_sysctl.c:1769 neigh_sysctl_unregister+0x74/0x90 net/core/neighbour.c:3877 addrconf_sysctl_unregister net/ipv6/addrconf.c:7209 [inline] addrconf_ifdown+0x1751/0x1a50 net/ipv6/addrconf.c:3951 addrconf_notify+0x405/0xf40 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] unregister_netdevice_many_notify+0x10ac/0x19c0 net/core/dev.c:11023 rtnl_newlink_create net/core/rtnetlink.c:3458 [inline] __rtnl_newlink net/core/rtnetlink.c:3647 [inline] rtnl_newlink+0x1cbf/0x20a0 net/core/rtnetlink.c:3660 rtnetlink_rcv_msg+0x87c/0xfc0 net/core/rtnetlink.c:6157 netlink_rcv_skb+0x1fb/0x450 net/netlink/af_netlink.c:2511 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5be/0x970 net/socket.c:2518 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2572 __sys_sendmsg net/socket.c:2601 [inline] __do_sys_sendmsg net/socket.c:2610 [inline] __se_sys_sendmsg+0x1bb/0x2a0 net/socket.c:2608 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888029396e00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff888029396e00, ffff888029396f00) The buggy address belongs to the physical page: page:ffffea0000a4e580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x29396 head:ffffea0000a4e580 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001d82480 dead000000000005 ffff888017441b40 raw: 0000000000000000 0000000000100010 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, tgid 1 (swapper/0), ts 9169879679, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] bus_add_driver+0xda/0x5a0 drivers/base/bus.c:604 driver_register+0x32d/0x430 drivers/base/driver.c:246 usb_register_driver+0x202/0x3d0 drivers/usb/core/driver.c:1062 au0828_init+0x135/0x162 drivers/media/usb/au0828/au0828-core.c:835 do_one_initcall+0x26a/0x840 init/main.c:1310 do_initcall_level+0x137/0x1e4 init/main.c:1383 do_initcalls+0x4b/0x8a init/main.c:1399 page_owner free stack trace missing Memory state around the buggy address: ffff888029396d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888029396d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888029396e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888029396e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888029396f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================