================================================================== BUG: KASAN: slab-out-of-bounds in decode_session6+0xe6d/0x1530 net/xfrm/xfrm_policy.c:3369 Read of size 1 at addr ffff888025653242 by task syz-executor.4/28860 CPU: 0 PID: 28860 Comm: syz-executor.4 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 decode_session6+0xe6d/0x1530 net/xfrm/xfrm_policy.c:3369 __xfrm_decode_session+0x50/0xb0 net/xfrm/xfrm_policy.c:3456 xfrm_decode_session include/net/xfrm.h:1149 [inline] vti_tunnel_xmit+0x26d/0x1b80 net/ipv4/ip_vti.c:294 __netdev_start_xmit include/linux/netdevice.h:4615 [inline] netdev_start_xmit include/linux/netdevice.h:4629 [inline] xmit_one net/core/dev.c:3473 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3489 sch_direct_xmit+0x19f/0xbe0 net/sched/sch_generic.c:342 qdisc_restart net/sched/sch_generic.c:407 [inline] __qdisc_run+0x4bc/0x1700 net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3758 [inline] __dev_queue_xmit+0x2084/0x3640 net/core/dev.c:4077 neigh_connected_output+0x3b6/0x510 net/core/neighbour.c:1552 neigh_output include/net/neighbour.h:538 [inline] ip6_finish_output2+0x56e/0x14f0 net/ipv6/ip6_output.c:126 ip6_fragment+0x1dea/0x2520 net/ipv6/ip6_output.c:907 __ip6_finish_output net/ipv6/ip6_output.c:189 [inline] __ip6_finish_output+0x8ae/0xe80 net/ipv6/ip6_output.c:170 ip6_finish_output+0x32/0x200 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x1e4/0x530 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] ip6_local_out+0xaf/0x1a0 net/ipv6/output_core.c:161 ip6_send_skb+0xb7/0x340 net/ipv6/ip6_output.c:1912 udp_v6_send_skb+0x7c3/0x15e0 net/ipv6/udp.c:1249 udpv6_sendmsg+0x230e/0x2c30 net/ipv6/udp.c:1547 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:641 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 ____sys_sendmsg+0x331/0x810 net/socket.c:2409 ___sys_sendmsg+0xf3/0x170 net/socket.c:2463 __sys_sendmmsg+0x195/0x470 net/socket.c:2549 __do_sys_sendmmsg net/socket.c:2578 [inline] __se_sys_sendmmsg net/socket.c:2575 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fbb936b1ae9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbb90c27188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007fbb937c4f60 RCX: 00007fbb936b1ae9 RDX: 0400000000000132 RSI: 0000000020004d80 RDI: 0000000000000007 RBP: 00007fbb9370bf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000004000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff1878dbbf R14: 00007fbb90c27300 R15: 0000000000022000 Allocated by task 28431: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:590 [inline] kzalloc include/linux/slab.h:724 [inline] kernfs_iop_get_link fs/kernfs/symlink.c:134 [inline] kernfs_iop_get_link+0x6a/0x6c0 fs/kernfs/symlink.c:125 pick_link fs/namei.c:1769 [inline] step_into+0x16e9/0x1c80 fs/namei.c:1826 open_last_lookups fs/namei.c:3373 [inline] path_openat+0x4a1/0x2750 fs/namei.c:3556 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_open fs/open.c:1236 [inline] __se_sys_open fs/open.c:1232 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1232 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 28431: kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749 slab_free mm/slub.c:3513 [inline] kfree+0xf6/0x560 mm/slub.c:4561 do_delayed_call include/linux/delayed_call.h:28 [inline] put_link fs/namei.c:1018 [inline] open_last_lookups fs/namei.c:3372 [inline] path_openat+0xbdc/0x2750 fs/namei.c:3556 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_open fs/open.c:1236 [inline] __se_sys_open fs/open.c:1232 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1232 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888025652000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 578 bytes to the right of 4096-byte region [ffff888025652000, ffff888025653000) The buggy address belongs to the page: page:ffffea0000959400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25650 head:ffffea0000959400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010c42140 raw: 0000000000000000 0000000000040004 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6564, ts 148365502993, free_ts 0 prep_new_page mm/page_alloc.c:2418 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369 alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191 alloc_slab_page mm/slub.c:1793 [inline] allocate_slab mm/slub.c:1930 [inline] new_slab+0x32d/0x4a0 mm/slub.c:1993 ___slab_alloc+0x918/0xfe0 mm/slub.c:3022 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109 slab_alloc_node mm/slub.c:3200 [inline] slab_alloc mm/slub.c:3242 [inline] __kmalloc_track_caller+0x2e7/0x320 mm/slub.c:4925 kmemdup+0x23/0x50 mm/util.c:128 kmemdup include/linux/fortify-string.h:304 [inline] __addrconf_sysctl_register+0x9d/0x3d0 net/ipv6/addrconf.c:7013 addrconf_sysctl_register net/ipv6/addrconf.c:7078 [inline] addrconf_sysctl_register+0x139/0x1d0 net/ipv6/addrconf.c:7067 ipv6_add_dev+0x96d/0x1160 net/ipv6/addrconf.c:455 addrconf_notify+0x60e/0x1ba0 net/ipv6/addrconf.c:3510 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919 call_netdevice_notifiers_extack net/core/dev.c:1931 [inline] call_netdevice_notifiers net/core/dev.c:1945 [inline] register_netdevice+0x1073/0x1500 net/core/dev.c:9686 wg_newlink+0x453/0x8b0 drivers/net/wireguard/device.c:354 page_owner free stack trace missing Memory state around the buggy address: ffff888025653100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888025653180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888025653200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888025653280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888025653300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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