=========================================[ 826.430923][T13555] ================================================================== BUG: KASAN: slab-use-after-free in dvb_device_open+0xc4/0x360 drivers/media/dvb-core/dvbdev.c:99 Read of size 8 at addr ffff88802c6bc818 by task syz.3.1790/13555 CPU: 0 UID: 0 PID: 13555 Comm: syz.3.1790 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 dvb_device_open+0xc4/0x360 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x4d0/0x5f0 fs/char_dev.c:411 do_dentry_open+0x83d/0x13e0 fs/open.c:947 vfs_open+0x3b/0x350 fs/open.c:1052 do_open fs/namei.c:4688 [inline] path_openat+0x2eea/0x3960 fs/namei.c:4847 do_file_open+0x23e/0x4a0 fs/namei.c:4876 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2ce27d68e 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:00007ff2cc515b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff2cc5166c0 RCX: 00007ff2ce27d68e RDX: 0000000000000002 RSI: 00007ff2cc515c00 RDI: ffffffffffffff9c RBP: 00007ff2cc515c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007ff2ce536038 R14: 00007ff2ce535fa0 R15: 00007fff57e0cef8 Allocated by task 5272: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5309 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5322 _kmalloc_noprof include/linux/slab.h:971 [inline] _kzalloc_noprof include/linux/slab.h:1284 [inline] fib6_info_alloc+0x30/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x142/0x860 net/ipv6/route.c:3828 ip6_route_add+0x49/0x1d0 net/ipv6/route.c:3957 addrconf_add_mroute+0x2d1/0x370 net/ipv6/addrconf.c:2560 addrconf_add_dev net/ipv6/addrconf.c:2578 [inline] inet6_addr_add+0x2e4/0xbd0 net/ipv6/addrconf.c:3047 inet6_rtm_newaddr+0xa17/0xe30 net/ipv6/addrconf.c:5086 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7062 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:797 __sock_sendmsg net/socket.c:812 [inline] ____sys_sendmsg+0x55c/0x870 net/socket.c:2716 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2770 __sys_sendmsg net/socket.c:2802 [inline] __do_sys_sendmsg net/socket.c:2807 [inline] __se_sys_sendmsg net/socket.c:2805 [inline] __x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2805 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 21: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2700 [inline] slab_free mm/slub.c:6284 [inline] kfree+0x1c5/0x6c0 mm/slub.c:6599 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core kernel/rcu/tree.c:2869 [inline] rcu_cpu_kthread+0x99e/0x1470 kernel/rcu/tree.c:2957 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 call_rcu_hurry include/linux/rcupdate.h:125 [inline] fib6_info_release include/net/ip6_fib.h:344 [inline] ip6_route_add+0x182/0x1d0 net/ipv6/route.c:3966 addrconf_add_mroute+0x2d1/0x370 net/ipv6/addrconf.c:2560 addrconf_add_dev net/ipv6/addrconf.c:2578 [inline] inet6_addr_add+0x2e4/0xbd0 net/ipv6/addrconf.c:3047 inet6_rtm_newaddr+0xa17/0xe30 net/ipv6/addrconf.c:5086 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7062 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x780/0x920 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:797 __sock_sendmsg net/socket.c:812 [inline] ____sys_sendmsg+0x55c/0x870 net/socket.c:2716 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2770 __sys_sendmsg net/socket.c:2802 [inline] __do_sys_sendmsg net/socket.c:2807 [inline] __se_sys_sendmsg net/socket.c:2805 [inline] __x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2805 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88802c6bc800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 24 bytes inside of freed 512-byte region [ffff88802c6bc800, ffff88802c6bca00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c6bc head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe21c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff88813fe21c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 0080000000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 18464194415, free_ts 18462803051 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x265c/0x26e0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5300 alloc_slab_page mm/slub.c:3289 [inline] allocate_slab+0x74/0x5e0 mm/slub.c:3404 new_slab mm/slub.c:3447 [inline] refill_objects+0x33c/0x3d0 mm/slub.c:7216 refill_sheaf mm/slub.c:2827 [inline] __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4665 alloc_from_pcs mm/slub.c:4763 [inline] slab_alloc_node mm/slub.c:4897 [inline] __kmalloc_cache_noprof+0x44e/0x690 mm/slub.c:5420 _kmalloc_noprof include/linux/slab.h:967 [inline] _kzalloc_noprof include/linux/slab.h:1284 [inline] device_private_init drivers/base/core.c:3602 [inline] device_add+0xbe/0xb90 drivers/base/core.c:3653 platform_device_add+0x46a/0x800 drivers/base/platform.c:762 vidtv_bridge_init+0x12/0x60 drivers/media/test-drivers/vidtv/vidtv_bridge.c:596 do_one_initcall+0x250/0x870 init/main.c:1347 do_initcall_level+0x104/0x190 init/main.c:1409 do_initcalls+0x59/0xa0 init/main.c:1425 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1658 kernel_init+0x1d/0x1d0 init/main.c:1548 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 page last free pid 10 tgid 10 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x10af/0x1190 mm/page_alloc.c:2950 stack_depot_save_flags+0x40e/0x810 lib/stackdepot.c:735 kasan_save_stack mm/kasan/common.c:58 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5309 [inline] __kmalloc_noprof+0x3e7/0x7b0 mm/slub.c:5322 _kmalloc_noprof include/linux/slab.h:971 [inline] _kzalloc_noprof include/linux/slab.h:1284 [inline] kobject_get_path+0xc5/0x2f0 lib/kobject.c:161 input_register_device+0x9f4/0x1140 drivers/input/input.c:2384 psmouse_connect+0xbb8/0x14d0 drivers/input/mouse/psmouse-base.c:1606 serio_connect_driver drivers/input/serio/serio.c:44 [inline] serio_driver_probe+0x7f/0xb0 drivers/input/serio/serio.c:748 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:706 __driver_probe_device+0x1e2/0x350 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __driver_attach+0x33c/0x600 drivers/base/dd.c:1292 bus_for_each_dev+0x23e/0x2c0 drivers/base/bus.c:383 serio_attach_driver drivers/input/serio/serio.c:777 [inline] serio_handle_event+0x1e4/0x1030 drivers/input/serio/serio.c:214 process_one_work+0x98b/0x1630 kernel/workqueue.c:3318 Memory state around the buggy address: ffff88802c6bc700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802c6bc780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802c6bc800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802c6bc880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802c6bc900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================