================================================================== BUG: KASAN: slab-use-after-free in hlist_add_head include/linux/list.h:1026 [inline] BUG: KASAN: slab-use-after-free in udp_tunnel_update_gro_lookup+0xfe/0x2c0 net/ipv4/udp_offload.c:60 Write of size 8 at addr ffff88806186fb70 by task syz.4.1266/10550 CPU: 0 UID: 0 PID: 10550 Comm: syz.4.1266 Not tainted 6.14.0-rc6-syzkaller-01279-gaedfbe251e1c #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_add_head include/linux/list.h:1026 [inline] udp_tunnel_update_gro_lookup+0xfe/0x2c0 net/ipv4/udp_offload.c:60 rxrpc_open_socket net/rxrpc/local_object.c:197 [inline] rxrpc_lookup_local+0xea5/0x1890 net/rxrpc/local_object.c:293 rxrpc_sendmsg+0x323/0x5f0 net/rxrpc/af_rxrpc.c:608 sock_sendmsg_nosec net/socket.c:709 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:724 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 ___sys_sendmsg net/socket.c:2618 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2650 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 RIP: 0033:0x7fa16958d169 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:00007fa16a464038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fa1697a6080 RCX: 00007fa16958d169 RDX: 0000000004000894 RSI: 0000400000002780 RDI: 0000000000000005 RBP: 00007fa16960e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa1697a6080 R15: 00007fff52e058d8 Allocated by task 10092: 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 inet_create+0x648/0xea0 net/ipv4/af_inet.c:326 __sock_create+0x4c0/0xa30 net/socket.c:1539 inet_ctl_sock_create+0xc2/0x250 net/ipv4/af_inet.c:1637 igmp_net_init+0xbb/0x150 net/ipv4/igmp.c:3125 ops_init+0x349/0x5b0 net/core/net_namespace.c:138 setup_net+0x287/0x9e0 net/core/net_namespace.c:362 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:516 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x57d/0xa70 kernel/fork.c:3342 __do_sys_unshare kernel/fork.c:3413 [inline] __se_sys_unshare kernel/fork.c:3411 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3411 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 8422: 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 inet_release+0x17d/0x200 net/ipv4/af_inet.c:435 __sock_release net/socket.c:647 [inline] sock_release+0x82/0x150 net/socket.c:675 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x812/0xd60 net/core/net_namespace.c:652 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff88806186f440 which belongs to the cache UDP of size 1856 The buggy address is located 1840 bytes inside of freed 1856-byte region [ffff88806186f440, ffff88806186fb80) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x61868 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88806b9bb301 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801bf0c3c0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 00000000f5000000 ffff88806b9bb301 head: 00fff00000000040 ffff88801bf0c3c0 dead000000000122 0000000000000000 head: 0000000000000000 0000000080100010 00000000f5000000 ffff88806b9bb301 head: 00fff00000000003 ffffea0001861a01 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 6054, tgid 6053 (syz.3.31), ts 85932091072, free_ts 85929496376 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 inet_create+0x648/0xea0 net/ipv4/af_inet.c:326 __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 page last free pid 5849 tgid 5849 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 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 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 getname_flags+0xb7/0x540 fs/namei.c:139 user_path_at+0x24/0x60 fs/namei.c:3071 inotify_find_inode fs/notify/inotify/inotify_user.c:377 [inline] __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:771 [inline] __se_sys_inotify_add_watch+0x19c/0xf20 fs/notify/inotify/inotify_user.c:729 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 Memory state around the buggy address: ffff88806186fa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806186fa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806186fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806186fb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806186fc00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================