================================================================== BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:980 [inline] BUG: KASAN: slab-use-after-free in hlist_del_init include/linux/list.h:1008 [inline] BUG: KASAN: slab-use-after-free in udp_tunnel_update_gro_lookup+0x169/0x2c0 net/ipv4/udp_offload.c:62 Write of size 8 at addr ffff88805f2f0728 by task syz.3.305/7272 CPU: 0 UID: 0 PID: 7272 Comm: syz.3.305 Not tainted 6.14.0-rc7-syzkaller-01433-g6bb0dcb3d321 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x16e/0x5b0 mm/kasan/report.c:521 kasan_report+0x143/0x180 mm/kasan/report.c:634 __hlist_del include/linux/list.h:980 [inline] hlist_del_init include/linux/list.h:1008 [inline] udp_tunnel_update_gro_lookup+0x169/0x2c0 net/ipv4/udp_offload.c:62 sk_common_release+0x71/0x2e0 net/core/sock.c:3896 inet_release+0x17d/0x200 net/ipv4/af_inet.c:435 __sock_release net/socket.c:647 [inline] sock_close+0xbc/0x240 net/socket.c:1389 __fput+0x3e9/0x9f0 fs/file_table.c:464 task_work_run+0x24f/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f523a78d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe004f7688 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f523a9a7ba0 RCX: 00007f523a78d169 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f523a9a7ba0 R08: 0000000000000000 R09: 00000008004f797f R10: 000000000003fd8c R11: 0000000000000246 R12: 000000000001e935 R13: 00007f523a9a6080 R14: ffffffffffffffff R15: 00007ffe004f77a0 Allocated by task 7273: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171 sk_prot_alloc+0x58/0x210 net/core/sock.c:2190 sk_alloc+0x3e/0x370 net/core/sock.c:2249 inet6_create+0x6ce/0x10f0 net/ipv6/af_inet6.c:193 __sock_create+0x4c0/0xa30 net/socket.c:1539 sock_create net/socket.c:1597 [inline] __sys_socket_create net/socket.c:1634 [inline] __sys_socket+0x150/0x3c0 net/socket.c:1681 __do_sys_socket net/socket.c:1695 [inline] __se_sys_socket net/socket.c:1693 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1693 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7273: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4609 [inline] kmem_cache_free+0x195/0x410 mm/slub.c:4711 sk_prot_free net/core/sock.c:2230 [inline] __sk_destruct+0x4fd/0x690 net/core/sock.c:2327 sock_put include/net/sock.h:1908 [inline] l2tp_tunnel_free net/l2tp/l2tp_core.c:163 [inline] l2tp_tunnel_put+0x1f6/0x4a0 net/l2tp/l2tp_core.c:203 pppol2tp_connect+0x110b/0x1960 net/l2tp/l2tp_ppp.c:841 __sys_connect_file net/socket.c:2036 [inline] __sys_connect+0x288/0x2d0 net/socket.c:2055 __do_sys_connect net/socket.c:2061 [inline] __se_sys_connect net/socket.c:2058 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2058 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805f2f0000 which belongs to the cache UDPv6 of size 2048 The buggy address is located 1832 bytes inside of freed 2048-byte region [ffff88805f2f0000, ffff88805f2f0800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805f2f6e80 pfn:0x5f2f0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88802f5f8801 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888029723640 dead000000000122 0000000000000000 raw: ffff88805f2f6e80 00000000800f0007 00000000f5000000 ffff88802f5f8801 head: 00fff00000000040 ffff888029723640 dead000000000122 0000000000000000 head: ffff88805f2f6e80 00000000800f0007 00000000f5000000 ffff88802f5f8801 head: 00fff00000000003 ffffea00017cbc01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5848, tgid 5848 (syz-executor), ts 83782312145, free_ts 27580354151 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4171 sk_prot_alloc+0x58/0x210 net/core/sock.c:2190 sk_alloc+0x3e/0x370 net/core/sock.c:2249 inet6_create+0x6ce/0x10f0 net/ipv6/af_inet6.c:193 __sock_create+0x4c0/0xa30 net/socket.c:1539 udp_sock_create6+0xe5/0x820 net/ipv6/ip6_udp_tunnel.c:24 udp_sock_create include/net/udp_tunnel.h:62 [inline] wg_socket_init+0x861/0xea0 drivers/net/wireguard/socket.c:398 wg_open+0x255/0x420 drivers/net/wireguard/device.c:51 __dev_open+0x45a/0x8a0 net/core/dev.c:1622 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 free_contig_range+0x14c/0x430 mm/page_alloc.c:6678 destroy_args+0x94/0x4b0 mm/debug_vm_pgtable.c:1017 debug_vm_pgtable+0x551/0x590 mm/debug_vm_pgtable.c:1397 do_one_initcall+0x248/0x930 init/main.c:1257 do_initcall_level+0x157/0x210 init/main.c:1319 do_initcalls+0x71/0xd0 init/main.c:1335 kernel_init_freeable+0x435/0x5d0 init/main.c:1568 kernel_init+0x1d/0x2b0 init/main.c:1457 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Memory state around the buggy address: ffff88805f2f0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805f2f0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805f2f0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805f2f0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805f2f0800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================