================================================================== BUG: KASAN: use-after-free in vlan_dev_get_iflink+0x70/0x80 net/8021q/vlan_dev.c:780 Read of size 4 at addr ffff888121f30100 by task kworker/u4:4/1117 CPU: 0 PID: 1117 Comm: kworker/u4:4 Not tainted 5.10.236-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 vlan_dev_get_iflink+0x70/0x80 net/8021q/vlan_dev.c:780 dev_get_iflink+0x6f/0xc0 net/core/dev.c:824 default_operstate net/core/link_watch.c:41 [inline] rfc2863_policy+0x127/0x2b0 net/core/link_watch.c:53 linkwatch_do_dev+0x3c/0x140 net/core/link_watch.c:160 linkwatch_forget_dev+0x170/0x180 net/core/link_watch.c:238 netdev_wait_allrefs net/core/dev.c:10214 [inline] netdev_run_todo+0x2ee/0xdc0 net/core/dev.c:10330 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112 default_device_exit_batch+0x38f/0x3f0 net/core/dev.c:11287 ops_exit_list net/core/net_namespace.c:190 [inline] cleanup_net+0x6e9/0xcb0 net/core/net_namespace.c:609 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447 kthread+0x34b/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 1607: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc+0xdb/0x110 mm/kasan/common.c:509 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1aa/0x330 mm/slub.c:4033 __kmalloc_node include/linux/slab.h:418 [inline] kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x82/0x130 mm/util.c:612 kvmalloc include/linux/mm.h:822 [inline] kvzalloc include/linux/mm.h:830 [inline] alloc_netdev_mqs+0x8e/0xcd0 net/core/dev.c:10526 rtnl_create_link+0x240/0x950 net/core/rtnetlink.c:3195 __rtnl_newlink net/core/rtnetlink.c:3472 [inline] rtnl_newlink+0x1399/0x2000 net/core/rtnetlink.c:3530 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2485 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline] netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1333 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] __sys_sendto+0x545/0x700 net/socket.c:2006 __do_sys_sendto net/socket.c:2018 [inline] __se_sys_sendto net/socket.c:2014 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2014 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 1117: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x121/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1595 [inline] slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kfree+0xc3/0x270 mm/slub.c:4191 kvfree+0x35/0x40 mm/util.c:647 netdev_freemem+0x3f/0x60 net/core/dev.c:10480 netdev_release+0x7f/0xb0 net/core/net-sysfs.c:1886 device_release+0x95/0x1c0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:713 [inline] kobject_release lib/kobject.c:744 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x178/0x260 lib/kobject.c:761 netdev_run_todo+0xc26/0xdc0 net/core/dev.c:10351 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112 default_device_exit_batch+0x38f/0x3f0 net/core/dev.c:11287 ops_exit_list net/core/net_namespace.c:190 [inline] cleanup_net+0x6e9/0xcb0 net/core/net_namespace.c:609 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447 kthread+0x34b/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff888121f30000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 256 bytes inside of 4096-byte region [ffff888121f30000, ffff888121f31000) The buggy address belongs to the page: page:ffffea000487cc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x121f30 head:ffffea000487cc00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042c00 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 1607, ts 63913824214, free_ts 63889190478 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5349 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x80/0x400 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x302/0x4b0 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] __kmalloc+0x204/0x330 mm/slub.c:4029 __kmalloc_node include/linux/slab.h:418 [inline] kmalloc_node include/linux/slab.h:575 [inline] kvmalloc_node+0x82/0x130 mm/util.c:612 kvmalloc include/linux/mm.h:822 [inline] kvzalloc include/linux/mm.h:830 [inline] alloc_netdev_mqs+0x8e/0xcd0 net/core/dev.c:10526 rtnl_create_link+0x240/0x950 net/core/rtnetlink.c:3195 __rtnl_newlink net/core/rtnetlink.c:3472 [inline] rtnl_newlink+0x1399/0x2000 net/core/rtnetlink.c:3530 rtnetlink_rcv_msg+0x955/0xc50 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2485 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1307 [inline] netlink_unicast+0x8df/0xac0 net/netlink/af_netlink.c:1333 netlink_sendmsg+0xa46/0xd00 net/netlink/af_netlink.c:1901 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page+0x9e/0x370 mm/page_alloc.c:5408 __free_pages+0x67/0xc0 mm/page_alloc.c:5419 free_pages+0x7c/0x90 mm/page_alloc.c:5430 kasan_depopulate_vmalloc_pte+0x6a/0x90 mm/kasan/shadow.c:354 apply_to_pte_range mm/memory.c:2504 [inline] apply_to_pmd_range mm/memory.c:2540 [inline] apply_to_pud_range mm/memory.c:2568 [inline] apply_to_p4d_range mm/memory.c:2596 [inline] __apply_to_page_range+0x720/0x9e0 mm/memory.c:2623 apply_to_existing_page_range+0x38/0x50 mm/memory.c:2874 kasan_release_vmalloc+0x9a/0xb0 mm/kasan/shadow.c:464 __purge_vmap_area_lazy+0x150e/0x1620 mm/vmalloc.c:1376 _vm_unmap_aliases+0x334/0x3b0 mm/vmalloc.c:1773 vm_unmap_aliases+0x19/0x20 mm/vmalloc.c:1796 change_page_attr_set_clr+0x308/0x1050 arch/x86/mm/pat/set_memory.c:1732 change_page_attr_clear arch/x86/mm/pat/set_memory.c:1789 [inline] set_memory_ro+0xa1/0xe0 arch/x86/mm/pat/set_memory.c:1935 bpf_jit_binary_lock_ro include/linux/filter.h:842 [inline] bpf_int_jit_compile+0x9829/0x9dc0 arch/x86/net/bpf_jit_comp.c:2130 bpf_prog_select_runtime+0x735/0x9c0 kernel/bpf/core.c:1876 bpf_migrate_filter net/core/filter.c:1298 [inline] bpf_prepare_filter+0x10a1/0x13c0 net/core/filter.c:1346 Memory state around the buggy address: ffff888121f30000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888121f30080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888121f30100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888121f30180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888121f30200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================