ci2 starts bisection 2025-12-18 10:50:23.127304563 +0000 UTC m=+1891235.304427710 bisecting fixing commit since 1edb21e89ce47f8b3cf6405a81d40d3147291b57 building syzkaller on 2c50b6a91afe391fad4d14f7b7d7167d570089dd ensuring issue is reproducible on original commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 9023408307973be72bbf5e99f25d0c63ad9c378c89d5f232cc4885d5f8f907ef all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] check whether we can drop unnecessary instrumentation disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 1382f8215199d9058eaee3748c6251554fa119bc4e15ed4d44625b1dea65b10c all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] the bug reproduces without the instrumentation disabling configs for [bug_or_warning locking atomic_sleep hang memleak ubsan], they are not needed kconfig minimization: base=4921 full=6220 leaves diff=256 split chunks (needed=false): <256> split chunk #0 of len 256 into 5 parts testing without sub-chunk 1/5 disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 3875196bcaa590b8ab4ecdf19326376dccd5f0d152fb2e9f2f210ef0b9fe293b all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 2/5 disabling configs for [atomic_sleep hang memleak ubsan bug_or_warning locking], they are not needed testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: e05bdc7d34e4fd689ebfda10cc547a495f2aa3a0f5c7f3fe5d91ad526f1a074c all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 3/5 disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 3e0591c224b58ab9cc2d8e4550a1e73e41271aab0590b6226f1ec0ee04d52bb3 all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 4/5 disabling configs for [memleak ubsan bug_or_warning locking atomic_sleep hang], they are not needed testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: 364406657c778fded3753bbae3c948002270c6374d9ee5ecc6f3dd57d3141989 all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] the chunk can be dropped testing without sub-chunk 5/5 disabling configs for [hang memleak ubsan bug_or_warning locking atomic_sleep], they are not needed testing commit 1edb21e89ce47f8b3cf6405a81d40d3147291b57 gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 failed building 1edb21e89ce47f8b3cf6405a81d40d3147291b57: net/socket.c:1191: undefined reference to `wext_handle_ioctl' net/socket.c:3390: undefined reference to `compat_wext_handle_ioctl' net/core/net-procfs.c:343: undefined reference to `wext_proc_exit' net/core/net-procfs.c:327: undefined reference to `wext_proc_init' minimized to 48 configs; suspects: [HID_ZEROPLUS USB_NET_CDC_SUBSET USB_NET_CDC_SUBSET_ENABLE USB_NET_DM9601 USB_NET_GL620A USB_NET_MCS7830 USB_NET_NET1080 USB_NET_PLUSB USB_NET_RNDIS_HOST USB_NET_SMSC75XX USB_NET_SMSC95XX USB_NET_SR9700 USB_NET_SR9800 USB_NET_ZAURUS USB_OHCI_HCD USB_OHCI_HCD_PCI USB_OHCI_HCD_PLATFORM USB_OTG USB_OTG_FSM USB_PRINTER USB_SERIAL USB_SERIAL_FTDI_SIO USB_SERIAL_GENERIC USB_SERIAL_PL2303 USB_STORAGE_ALAUDA USB_STORAGE_CYPRESS_ATACB USB_STORAGE_DATAFAB USB_STORAGE_FREECOM USB_STORAGE_ISD200 USB_STORAGE_JUMPSHOT USB_STORAGE_KARMA USB_STORAGE_ONETOUCH USB_STORAGE_SDDR09 USB_STORAGE_SDDR55 USB_STORAGE_USBAT USB_TRANCEVIBRATOR USB_U_AUDIO USB_U_ETHER USB_U_SERIAL USB_WDM USB_XHCI_PCI_RENESAS WLAN WLAN_VENDOR_ATH WLAN_VENDOR_ATMEL WLAN_VENDOR_BROADCOM WLAN_VENDOR_INTERSIL WLAN_VENDOR_MARVELL WLAN_VENDOR_MEDIATEK WLAN_VENDOR_MICROCHIP WLAN_VENDOR_RALINK WLAN_VENDOR_REALTEK WLAN_VENDOR_RSI WLAN_VENDOR_ZYDAS ZEROPLUS_FF] disabling configs for [ubsan bug_or_warning locking atomic_sleep hang memleak], they are not needed testing current HEAD 050dc55b0457aa6986b7618175ec7ccae95b842a testing commit 050dc55b0457aa6986b7618175ec7ccae95b842a gcc compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.40 kernel signature: a040c8ff4ecd5ea570f1ea790b4fee5f692e3f988754b244d8a0c8f04dc5c167 all runs: crashed: KASAN: use-after-free Read in vlan_dev_get_iflink representative crash: KASAN: use-after-free Read in vlan_dev_get_iflink, types: [KASAN-USE-AFTER-FREE-READ] crash still not fixed/happens on the oldest tested release revisions tested: 7, total time: 1h18m18.140438224s (build: 35m7.607265697s, test: 41m7.963239872s) crash still not fixed or there were kernel test errors commit msg: Revert "net/sched: act_connmark: handle errno on tcf_idr_check_alloc" crash: KASAN: use-after-free Read in vlan_dev_get_iflink ================================================================== BUG: KASAN: use-after-free in vlan_dev_get_iflink+0x62/0x70 net/8021q/vlan_dev.c:766 Read of size 4 at addr ffff8881120c60d0 by task kworker/u4:2/52 CPU: 0 PID: 52 Comm: kworker/u4:2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x38/0x49 lib/dump_stack.c:106 print_address_description.constprop.0+0x24/0x160 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report.cold+0x82/0xdb mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 vlan_dev_get_iflink+0x62/0x70 net/8021q/vlan_dev.c:766 dev_get_iflink+0x64/0xc0 net/core/dev.c:711 rfc2863_policy+0x1a7/0x220 net/core/link_watch.c:41 linkwatch_do_dev+0x28/0x100 net/core/link_watch.c:160 linkwatch_forget_dev+0x157/0x200 net/core/link_watch.c:238 netdev_run_todo+0x262/0x7e0 net/core/dev.c:10687 rtnl_unlock+0x9/0x10 net/core/rtnetlink.c:112 default_device_exit_batch+0x3cf/0x500 net/core/dev.c:11684 ops_exit_list+0xde/0x130 net/core/net_namespace.c:177 cleanup_net+0x41f/0xb60 net/core/net_namespace.c:599 process_one_work+0x62c/0xec0 kernel/workqueue.c:2325 worker_thread+0x48e/0xdb0 kernel/workqueue.c:2472 kthread+0x324/0x3e0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Allocated by task 440: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] ____kasan_kmalloc mm/kasan/common.c:471 [inline] __kasan_kmalloc+0xae/0xe0 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] __kmalloc+0x2e6/0x550 mm/slub.c:4436 __kmalloc_node include/linux/slab.h:487 [inline] kmalloc_node include/linux/slab.h:642 [inline] kvmalloc_node+0x1f3/0x230 mm/util.c:621 kvmalloc include/linux/mm.h:862 [inline] kvzalloc include/linux/mm.h:870 [inline] alloc_netdev_mqs+0x5e/0xd70 net/core/dev.c:10900 rtnl_create_link+0x89a/0xc30 net/core/rtnetlink.c:3232 __rtnl_newlink+0xd0a/0x15d0 net/core/rtnetlink.c:3514 rtnl_newlink+0x5f/0x90 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x334/0x970 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x133/0x3c0 net/netlink/af_netlink.c:2511 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x642/0xad0 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x810/0xd10 net/netlink/af_netlink.c:1922 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg+0xb5/0xf0 net/socket.c:716 __sys_sendto+0x1e3/0x2f0 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xdc/0x1a0 net/socket.c:2071 x64_sys_call+0x84e/0x990 arch/x86/include/generated/asm/syscalls_64.h:45 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x33/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 52: kasan_save_stack+0x26/0x50 mm/kasan/common.c:38 kasan_set_track+0x25/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x24/0x40 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:365 [inline] ____kasan_slab_free mm/kasan/common.c:327 [inline] __kasan_slab_free+0x111/0x150 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x94/0x1a0 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc2/0x2a0 mm/slub.c:4588 kvfree+0x25/0x30 mm/util.c:661 netdev_freemem+0x47/0x60 net/core/dev.c:10854 netdev_release+0x68/0x80 net/core/net-sysfs.c:1903 device_release+0x9d/0x1a0 drivers/base/core.c:2255 kobject_cleanup+0xb5/0x180 lib/kobject.c:713 kobject_release lib/kobject.c:744 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x45/0x60 lib/kobject.c:761 netdev_run_todo+0x4fa/0x7e0 net/core/dev.c:10710 rtnl_unlock+0x9/0x10 net/core/rtnetlink.c:112 default_device_exit_batch+0x3cf/0x500 net/core/dev.c:11684 ops_exit_list+0xde/0x130 net/core/net_namespace.c:177 cleanup_net+0x41f/0xb60 net/core/net_namespace.c:599 process_one_work+0x62c/0xec0 kernel/workqueue.c:2325 worker_thread+0x48e/0xdb0 kernel/workqueue.c:2472 kthread+0x324/0x3e0 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff8881120c6000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 208 bytes inside of 4096-byte region [ffff8881120c6000, ffff8881120c7000) The buggy address belongs to the page: page:ffffea0004483000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1120c0 head:ffffea0004483000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043380 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d60c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 440, ts 55774204078, free_ts 55770567052 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook mm/page_alloc.c:2605 [inline] prep_new_page+0x1a2/0x310 mm/page_alloc.c:2611 get_page_from_freelist+0x1ce2/0x30a0 mm/page_alloc.c:4485 __alloc_pages+0x300/0x2d50 mm/page_alloc.c:5808 __alloc_pages_node include/linux/gfp.h:595 [inline] alloc_pages_node include/linux/gfp.h:609 [inline] alloc_pages include/linux/gfp.h:622 [inline] alloc_slab_page mm/slub.c:1798 [inline] allocate_slab+0x39d/0x530 mm/slub.c:1937 new_slab mm/slub.c:2000 [inline] ___slab_alloc.constprop.0+0x3ca/0x890 mm/slub.c:3033 __slab_alloc.constprop.0+0x42/0x80 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc+0x505/0x550 mm/slub.c:4432 __kmalloc_node include/linux/slab.h:487 [inline] kmalloc_node include/linux/slab.h:642 [inline] kvmalloc_node+0x1f3/0x230 mm/util.c:621 kvmalloc include/linux/mm.h:862 [inline] kvzalloc include/linux/mm.h:870 [inline] alloc_netdev_mqs+0x5e/0xd70 net/core/dev.c:10900 rtnl_create_link+0x89a/0xc30 net/core/rtnetlink.c:3232 __rtnl_newlink+0xd0a/0x15d0 net/core/rtnetlink.c:3514 rtnl_newlink+0x5f/0x90 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x334/0x970 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x133/0x3c0 net/netlink/af_netlink.c:2511 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x642/0xad0 net/netlink/af_netlink.c:1348 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare+0x1b6/0x4c0 mm/page_alloc.c:1544 free_unref_page_prepare mm/page_alloc.c:3534 [inline] free_unref_page+0x84/0x760 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0xd7/0xf0 mm/page_alloc.c:5884 __free_slab+0xdb/0x1c0 mm/slub.c:2025 free_slab mm/slub.c:2040 [inline] discard_slab+0x2b/0x40 mm/slub.c:2046 __unfreeze_partials+0x1e2/0x230 mm/slub.c:2532 put_cpu_partial+0x96/0xb0 mm/slub.c:2612 __slab_free+0x21e/0x4d0 mm/slub.c:3395 do_slab_free mm/slub.c:3514 [inline] ___cache_free+0x1ee/0x230 mm/slub.c:3535 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6e/0x150 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x15f/0x1c0 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xaa/0xc0 mm/kasan/common.c:443 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook mm/slab.h:550 [inline] slab_alloc_node mm/slub.c:3245 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x35b/0x540 mm/slub.c:4954 kvasprintf+0xb4/0x110 lib/kasprintf.c:25 kvasprintf_const+0x4b/0x140 lib/kasprintf.c:49 kobject_set_name_vargs+0x46/0x120 lib/kobject.c:297 Memory state around the buggy address: ffff8881120c5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881120c6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881120c6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881120c6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881120c6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================