syzbot

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BUG: KASAN: slab-use-after-free in __xfrm_state_lookup+0x6b2/0x8d0 net/xfrm/xfrm_state.c:1084
Read of size 2 at addr ffff888025d64d22 by task syz.2.2787/13629

CPU: 1 PID: 13629 Comm: syz.2.2787 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 __xfrm_state_lookup+0x6b2/0x8d0 net/xfrm/xfrm_state.c:1084
 __xfrm_state_locate net/xfrm/xfrm_state.c:1132 [inline]
 xfrm_state_add+0x25e/0xe20 net/xfrm/xfrm_state.c:1665
 xfrm_add_sa+0x26f7/0x30a0 net/xfrm/xfrm_user.c:805
 xfrm_user_rcv_msg+0x596/0x870 net/xfrm/xfrm_user.c:3169
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3191
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f512b18ebe9
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:00007f51293f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f512b3b5fa0 RCX: 00007f512b18ebe9
RDX: 0000000000000000 RSI: 00002000000035c0 RDI: 0000000000000003
RBP: 00007f512b211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f512b3b6038 R14: 00007f512b3b5fa0 R15: 00007ffdb036ee28
 </TASK>

Allocated by task 8532:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfrm_state_alloc+0x22/0x2a0 net/xfrm/xfrm_state.c:661
 xfrm_state_construct net/xfrm/xfrm_user.c:689 [inline]
 xfrm_add_sa+0xfe5/0x30a0 net/xfrm/xfrm_user.c:799
 xfrm_user_rcv_msg+0x596/0x870 net/xfrm/xfrm_user.c:3169
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3191
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888025d64c00
 which belongs to the cache xfrm_state of size 848
The buggy address is located 290 bytes inside of
 freed 848-byte region [ffff888025d64c00, ffff888025d64f50)

The buggy address belongs to the physical page:
page:ffffea0000975900 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888025d65c00 pfn:0x25d64
head:ffffea0000975900 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888141ada280 dead000000000122 0000000000000000
raw: ffff888025d65c00 0000000080100008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 6406, tgid 6405 (syz.0.253), ts 93898460911, free_ts 93678398690
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 slab_alloc mm/slub.c:3493 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3500 [inline]
 kmem_cache_alloc+0x1b7/0x2e0 mm/slub.c:3509
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 xfrm_state_alloc+0x22/0x2a0 net/xfrm/xfrm_state.c:661
 pfkey_msg2xfrm_state net/key/af_key.c:1122 [inline]
 pfkey_add+0x6e1/0x2da0 net/key/af_key.c:1503
 pfkey_process net/key/af_key.c:2847 [inline]
 pfkey_sendmsg+0xbed/0x1050 net/key/af_key.c:3698
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 free_large_kmalloc+0x101/0x1a0 mm/slab_common.c:984
 bpf_check+0x62c6/0xe970 kernel/bpf/verifier.c:20555
 bpf_prog_load+0x11cb/0x16d0 kernel/bpf/syscall.c:2744
 __sys_bpf+0x55a/0x800 kernel/bpf/syscall.c:5467
 __do_sys_bpf kernel/bpf/syscall.c:5571 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5569 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5569
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff888025d64c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888025d64c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888025d64d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888025d64d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888025d64e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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