================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:27 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:147 [inline] BUG: KASAN: use-after-free in inet_twsk_purge+0x1fe/0x620 net/ipv4/inet_timewait_sock.c:278 Read of size 4 at addr ffff8881115439c4 by task kworker/u4:4/564 CPU: 0 PID: 564 Comm: kworker/u4:4 Tainted: G W 5.10.238-syzkaller-00282-gd76d4cd0623a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: netns cleanup_net Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 mm/kasan/generic.c:189 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/asm-generic/atomic-instrumented.h:27 [inline] refcount_read include/linux/refcount.h:147 [inline] inet_twsk_purge+0x1fe/0x620 net/ipv4/inet_timewait_sock.c:278 tcpv6_net_exit_batch+0x1a/0x20 net/ipv6/tcp_ipv6.c:2194 ops_exit_list net/core/net_namespace.c:190 [inline] cleanup_net+0x5fb/0xb70 net/core/net_namespace.c:609 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Allocated by task 1464: 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_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583 slab_alloc_node mm/slub.c:2947 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960 kmem_cache_zalloc include/linux/slab.h:654 [inline] net_alloc net/core/net_namespace.c:421 [inline] copy_net_ns+0x13f/0x520 net/core/net_namespace.c:473 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:231 ksys_unshare+0x4ac/0x7d0 kernel/fork.c:3156 __do_sys_unshare kernel/fork.c:3224 [inline] __se_sys_unshare kernel/fork.c:3222 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3222 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x52/0x310 kernel/workqueue.c:1352 __queue_work+0x923/0xca0 kernel/workqueue.c:1518 queue_work_on+0xd5/0x130 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:515 [inline] schedule_work include/linux/workqueue.h:576 [inline] xfrm_hash_grow_check+0xd7/0x140 net/xfrm/xfrm_state.c:1000 xfrm_state_find+0x24e8/0x2880 net/xfrm/xfrm_state.c:1156 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2398 [inline] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2443 [inline] xfrm_resolve_and_create_bundle+0x626/0x28d0 net/xfrm/xfrm_policy.c:2736 xfrm_lookup_with_ifid+0x8eb/0x1980 net/xfrm/xfrm_policy.c:3070 xfrm_lookup net/xfrm/xfrm_policy.c:3194 [inline] xfrm_lookup_route+0x3c/0x170 net/xfrm/xfrm_policy.c:3205 ip_route_output_flow+0x1d2/0x2d0 net/ipv4/route.c:2796 udp_sendmsg+0x121f/0x2080 net/ipv4/udp.c:1231 inet_sendmsg+0xa5/0xc0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmmsg+0x273/0x450 net/socket.c:2516 __do_sys_sendmmsg net/socket.c:2545 [inline] __se_sys_sendmmsg net/socket.c:2542 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2542 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 insert_work+0x52/0x310 kernel/workqueue.c:1352 __queue_work+0x923/0xca0 kernel/workqueue.c:1518 queue_work_on+0xd5/0x130 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:515 [inline] schedule_work include/linux/workqueue.h:576 [inline] xfrm_hash_grow_check+0xd7/0x140 net/xfrm/xfrm_state.c:1000 xfrm_state_find+0x24e8/0x2880 net/xfrm/xfrm_state.c:1156 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2398 [inline] xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2443 [inline] xfrm_resolve_and_create_bundle+0x626/0x28d0 net/xfrm/xfrm_policy.c:2736 xfrm_lookup_with_ifid+0x8eb/0x1980 net/xfrm/xfrm_policy.c:3070 xfrm_lookup net/xfrm/xfrm_policy.c:3194 [inline] xfrm_lookup_route+0x3c/0x170 net/xfrm/xfrm_policy.c:3205 ip_route_output_flow+0x1d2/0x2d0 net/ipv4/route.c:2796 udp_sendmsg+0x121f/0x2080 net/ipv4/udp.c:1231 inet_sendmsg+0xa5/0xc0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmmsg+0x273/0x450 net/socket.c:2516 __do_sys_sendmmsg net/socket.c:2545 [inline] __se_sys_sendmmsg net/socket.c:2542 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2542 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff8881115439c0 which belongs to the cache net_namespace of size 4672 The buggy address is located 4 bytes inside of 4672-byte region [ffff8881115439c0, ffff888111544c00) The buggy address belongs to the page: page:ffffea0004455000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111540 head:ffffea0004455000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888107fdc000 raw: 0000000000000000 0000000080060006 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 1438, ts 68491942346, free_ts 68488129267 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5357 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x84/0x3f0 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x2a6/0x450 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] kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960 kmem_cache_zalloc include/linux/slab.h:654 [inline] net_alloc net/core/net_namespace.c:421 [inline] copy_net_ns+0x13f/0x520 net/core/net_namespace.c:473 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110 copy_namespaces+0x1d1/0x220 kernel/nsproxy.c:179 copy_process+0x11b8/0x32c0 kernel/fork.c:2271 kernel_clone+0x23f/0x940 kernel/fork.c:2650 __do_sys_clone kernel/fork.c:2776 [inline] __se_sys_clone kernel/fork.c:2760 [inline] __x64_sys_clone+0x176/0x1d0 kernel/fork.c:2760 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb 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_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5418 [inline] __free_pages+0xdd/0x380 mm/page_alloc.c:5427 __free_slab+0xcf/0x190 mm/slub.c:1894 free_slab mm/slub.c:1909 [inline] discard_slab mm/slub.c:1915 [inline] unfreeze_partials+0x15f/0x190 mm/slub.c:2410 put_cpu_partial+0xc1/0x180 mm/slub.c:2446 __slab_free+0x2c9/0x3a0 mm/slub.c:3095 do_slab_free mm/slub.c:3191 [inline] ___cache_free+0x111/0x130 mm/slub.c:3210 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583 slab_alloc_node mm/slub.c:2947 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960 getname_flags+0xb9/0x500 fs/namei.c:141 user_path_at_empty+0x2f/0x50 fs/namei.c:2740 do_readlinkat+0xd4/0x480 fs/stat.c:414 Memory state around the buggy address: ffff888111543880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff888111543900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888111543980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff888111543a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111543a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================