================================================================== BUG: KASAN: use-after-free in dvb_device_open+0xc5/0x360 drivers/media/dvb-core/dvbdev.c:99 Read of size 8 at addr ffff8880299c6218 by task syz.1.361/6174 CPU: 1 PID: 6174 Comm: syz.1.361 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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+0xc5/0x360 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x585/0x5f0 fs/char_dev.c:414 do_dentry_open+0x7dd/0x10b0 fs/open.c:882 do_open fs/namei.c:3677 [inline] path_openat+0x2674/0x2f10 fs/namei.c:3834 do_filp_open+0x1ee/0x420 fs/namei.c:3861 do_sys_openat2+0x14b/0x4f0 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: 0033:0x7fb486d5e98e 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:00007fb487cd4b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb487cd56c0 RCX: 00007fb486d5e98e RDX: 0000000000000400 RSI: 00007fb487cd4c00 RDI: ffffffffffffff9c RBP: 00007fb487cd4c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fb487026128 R14: 00007fb487026090 R15: 00007ffee141f1c8 Allocated by task 6026: 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 kmalloc include/linux/slab.h:563 [inline] siw_cm_alloc_work+0xbf/0x3b0 drivers/infiniband/sw/siw/siw_cm.c:291 siw_create_listen+0x507/0xe20 drivers/infiniband/sw/siw/siw_cm.c:1831 iw_cm_listen+0x15f/0x220 drivers/infiniband/core/iwcm.c:585 cma_iw_listen drivers/infiniband/core/cma.c:2652 [inline] rdma_listen+0xafd/0xe50 drivers/infiniband/core/cma.c:3933 cma_listen_on_dev+0x3f5/0x720 drivers/infiniband/core/cma.c:2711 cma_add_one+0x638/0xa90 drivers/infiniband/core/cma.c:5338 add_client_context+0x375/0x7a0 drivers/infiniband/core/device.c:731 enable_device_and_get+0x195/0x3d0 drivers/infiniband/core/device.c:1342 ib_register_device+0x1088/0x1350 drivers/infiniband/core/device.c:1430 siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline] siw_newlink+0x9cf/0xe60 drivers/infiniband/sw/siw/siw_main.c:513 nldev_newlink+0x58f/0x610 drivers/infiniband/core/nldev.c:1720 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline] rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6e7/0xa20 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1877 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609 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 6026: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1f0 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+0x133/0x1b0 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xb6/0x200 mm/slub.c:3700 siw_cm_free_work drivers/infiniband/sw/siw/siw_cm.c:195 [inline] __siw_cep_dealloc drivers/infiniband/sw/siw/siw_cm.c:261 [inline] kref_put include/linux/kref.h:65 [inline] siw_cep_put+0x263/0x4c0 drivers/infiniband/sw/siw/siw_cm.c:442 siw_drop_listeners drivers/infiniband/sw/siw/siw_cm.c:1932 [inline] siw_destroy_listen+0x496/0x670 drivers/infiniband/sw/siw/siw_cm.c:1942 destroy_cm_id+0x3aa/0x6c0 drivers/infiniband/core/iwcm.c:401 iw_destroy_cm_id+0x14/0x90 drivers/infiniband/core/iwcm.c:453 _destroy_id+0x817/0x1170 drivers/infiniband/core/cma.c:2027 cma_send_device_removal_put drivers/infiniband/core/cma.c:5239 [inline] cma_process_remove+0x65e/0xc40 drivers/infiniband/core/cma.c:5264 cma_add_one+0x7da/0xa90 drivers/infiniband/core/cma.c:5352 add_client_context+0x375/0x7a0 drivers/infiniband/core/device.c:731 enable_device_and_get+0x195/0x3d0 drivers/infiniband/core/device.c:1342 ib_register_device+0x1088/0x1350 drivers/infiniband/core/device.c:1430 siw_device_register drivers/infiniband/sw/siw/siw_main.c:72 [inline] siw_newlink+0x9cf/0xe60 drivers/infiniband/sw/siw/siw_main.c:513 nldev_newlink+0x58f/0x610 drivers/infiniband/core/nldev.c:1720 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline] rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6e7/0xa20 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1877 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609 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 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+0x103/0x890 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:3885 addrconf_sysctl_unregister net/ipv6/addrconf.c:7224 [inline] addrconf_ifdown+0x173d/0x1a30 net/ipv6/addrconf.c:3958 addrconf_notify+0x405/0xf60 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+0x10b1/0x1990 net/core/dev.c:11023 unregister_netdevice_many net/core/dev.c:11077 [inline] unregister_netdevice_queue net/core/dev.c:10960 [inline] unregister_netdevice include/linux/netdevice.h:3077 [inline] unregister_netdev+0x14c/0x1c0 net/core/dev.c:11095 gprs_attach+0x466/0x520 net/phonet/pep-gprs.c:287 pep_setsockopt+0x35a/0x530 net/phonet/pep.c:1049 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2288 __do_sys_setsockopt net/socket.c:2299 [inline] __se_sys_setsockopt net/socket.c:2296 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2296 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 ffff8880299c6200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff8880299c6200, ffff8880299c6300) The buggy address belongs to the physical page: page:ffffea0000a67180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x299c6 head:ffffea0000a67180 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000c20180 dead000000000002 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 12110423649, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 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+0xdc/0x5d0 drivers/base/bus.c:604 driver_register+0x32d/0x430 drivers/base/driver.c:246 usb_register_driver+0x201/0x3c0 drivers/usb/core/driver.c:1062 pvr_init+0x7e/0x133 drivers/media/usb/pvrusb2/pvrusb2-main.c:122 do_one_initcall+0x257/0x800 init/main.c:1270 do_initcall_level+0x13d/0x1ed init/main.c:1343 do_initcalls+0x4b/0x8a init/main.c:1359 page_owner free stack trace missing Memory state around the buggy address: ffff8880299c6100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880299c6180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880299c6200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880299c6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880299c6300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================