syzbot


KASAN: slab-use-after-free Read in udp_tunnel_update_gro_lookup

Status: upstream: reported on 2025/03/19 08:33
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+1fb3291cc1beeb3c315a@syzkaller.appspotmail.com
First crash: 1d05h, last: 2h21m
Discussions (2)
Title Replies (including bot) Last reply
[PATCH net-next] udp_tunnel: properly deal with xfrm gro encap. 4 (4) 2025/03/19 17:44
[syzbot] [net?] KASAN: slab-use-after-free Read in udp_tunnel_update_gro_lookup 0 (1) 2025/03/19 08:33

Sample crash report:
syz_tun: left promiscuous mode
==================================================================
BUG: KASAN: slab-use-after-free in udp_tunnel_update_gro_lookup+0x23c/0x2c0 net/ipv4/udp_offload.c:65
Read of size 8 at addr ffff88805d53b5a8 by task syz.3.773/8645

CPU: 1 UID: 0 PID: 8645 Comm: syz.3.773 Not tainted 6.14.0-rc6-syzkaller-01313-g23c9ff659140 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __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
 udp_tunnel_update_gro_lookup+0x23c/0x2c0 net/ipv4/udp_offload.c:65
 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_release+0x82/0x150 net/socket.c:675
 sock_free drivers/net/wireguard/socket.c:339 [inline]
 wg_socket_reinit+0x215/0x380 drivers/net/wireguard/socket.c:435
 wg_stop+0x59f/0x600 drivers/net/wireguard/device.c:133
 __dev_close_many+0x3a6/0x700 net/core/dev.c:1717
 __dev_close net/core/dev.c:1729 [inline]
 __dev_change_flags+0x30e/0x6f0 net/core/dev.c:9358
 netif_change_flags+0x8b/0x1a0 net/core/dev.c:9423
 do_setlink+0xf42/0x40f0 net/core/rtnetlink.c:3142
 rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
 rtnl_newlink+0x141c/0x1d90 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6945
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883
 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: 0033:0x7f91b058d169
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:00007f91b1431038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f91b07a5fa0 RCX: 00007f91b058d169
RDX: 0000000000000000 RSI: 0000400000000100 RDI: 0000000000000008
RBP: 00007f91b060e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f91b07a5fa0 R15: 00007ffe0ea31c28
 </TASK>

Allocated by task 8190:
 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
 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 8189:
 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_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
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 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 ffff88805d53ae80
 which belongs to the cache UDP of size 1856
The buggy address is located 1832 bytes inside of
 freed 1856-byte region [ffff88805d53ae80, ffff88805d53b5c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805d53ae80 pfn:0x5d538
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88803491e601
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888020ac0b40 dead000000000122 0000000000000000
raw: ffff88805d53ae80 000000008010000b 00000000f5000000 ffff88803491e601
head: 00fff00000000040 ffff888020ac0b40 dead000000000122 0000000000000000
head: ffff88805d53ae80 000000008010000b 00000000f5000000 ffff88803491e601
head: 00fff00000000003 ffffea0001754e01 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 7431, tgid 7430 (syz.4.447), ts 118464427617, free_ts 118450905594
 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
 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
page last free pid 7429 tgid 7428 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
 __folio_put+0x2b3/0x360 mm/swap.c:112
 folio_put include/linux/mm.h:1489 [inline]
 free_large_kmalloc+0xfe/0x180 mm/slub.c:4728
 kfree+0x212/0x430 mm/slub.c:4751
 wg_destruct+0x278/0x2e0 drivers/net/wireguard/device.c:265
 netdev_run_todo+0xd46/0xf30 net/core/dev.c:11291
 rtnl_unlock net/core/rtnetlink.c:157 [inline]
 rtnl_net_unlock include/linux/rtnetlink.h:135 [inline]
 rtnl_dellink+0x761/0x8c0 net/core/rtnetlink.c:3562
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6945
 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2534
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883
 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

Memory state around the buggy address:
 ffff88805d53b480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805d53b500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805d53b580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                  ^
 ffff88805d53b600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff88805d53b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (22):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/19 20:13 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in udp_tunnel_update_gro_lookup
2025/03/19 06:57 net-next 23c9ff659140 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in udp_tunnel_update_gro_lookup
2025/03/19 05:23 net-next 23c9ff659140 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in udp_tunnel_update_gro_lookup
2025/03/18 17:00 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in udp_tunnel_update_gro_lookup
2025/03/19 20:19 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 20:13 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 19:23 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 19:11 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 18:48 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 17:58 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 17:04 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 14:38 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 13:39 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 12:04 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 11:27 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 11:15 net-next 23c9ff659140 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 01:16 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 01:04 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/19 01:02 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/18 23:00 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/18 22:49 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
2025/03/18 17:11 net-next aedfbe251e1c 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Write in udp_tunnel_update_gro_lookup
* Struck through repros no longer work on HEAD.