================================================================== BUG: KASAN: use-after-free in decode_session6 net/xfrm/xfrm_policy.c:3394 [inline] BUG: KASAN: use-after-free in __xfrm_decode_session+0x1cfb/0x2e90 net/xfrm/xfrm_policy.c:3486 Read of size 1 at addr ffff88805c16ef91 by task syz-executor.1/3614 CPU: 0 PID: 3614 Comm: syz-executor.1 Not tainted 5.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 decode_session6 net/xfrm/xfrm_policy.c:3394 [inline] __xfrm_decode_session+0x1cfb/0x2e90 net/xfrm/xfrm_policy.c:3486 xfrm_decode_session_reverse include/net/xfrm.h:1145 [inline] icmpv6_route_lookup+0x2fe/0x470 net/ipv6/icmp.c:388 icmp6_send+0x1263/0x23b0 net/ipv6/icmp.c:588 icmpv6_send+0xde/0x210 net/ipv6/ip6_icmp.c:43 ip6_link_failure+0x26/0x520 net/ipv6/route.c:2665 dst_link_failure include/net/dst.h:418 [inline] ip6_tnl_xmit+0x460/0x3470 net/ipv6/ip6_tunnel.c:1248 ip6ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1402 [inline] ip6_tnl_start_xmit+0x89a/0x1dc0 net/ipv6/ip6_tunnel.c:1428 __netdev_start_xmit include/linux/netdevice.h:4533 [inline] netdev_start_xmit include/linux/netdevice.h:4547 [inline] xmit_one net/core/dev.c:3477 [inline] dev_hard_start_xmit+0x1a4/0x9b0 net/core/dev.c:3493 sch_direct_xmit+0x345/0xc20 net/sched/sch_generic.c:313 qdisc_restart net/sched/sch_generic.c:376 [inline] __qdisc_run+0x4d1/0x17b0 net/sched/sch_generic.c:384 __dev_xmit_skb net/core/dev.c:3716 [inline] __dev_queue_xmit+0x165b/0x30a0 net/core/dev.c:4021 neigh_output include/net/neighbour.h:510 [inline] ip6_finish_output2+0x1091/0x25b0 net/ipv6/ip6_output.c:117 __ip6_finish_output+0x442/0xab0 net/ipv6/ip6_output.c:143 ip6_finish_output+0x34/0x1f0 net/ipv6/ip6_output.c:153 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x239/0x810 net/ipv6/ip6_output.c:176 dst_output include/net/dst.h:435 [inline] ip6_local_out+0xaf/0x1a0 net/ipv6/output_core.c:179 ip6_send_skb+0xb4/0x340 net/ipv6/ip6_output.c:1865 udp_v6_send_skb.isra.0+0x7b5/0x15c0 net/ipv6/udp.c:1175 udpv6_sendmsg+0x233f/0x2b50 net/ipv6/udp.c:1473 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:577 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x308/0x7e0 net/socket.c:2362 ___sys_sendmsg+0x100/0x170 net/socket.c:2416 __sys_sendmmsg+0x195/0x480 net/socket.c:2506 __do_sys_sendmmsg net/socket.c:2535 [inline] __se_sys_sendmmsg net/socket.c:2532 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2532 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc09b803c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004fc320 RCX: 000000000045c829 RDX: 00000000000000c6 RSI: 0000000020006d00 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008dd R14: 00000000004cb81f R15: 00007fc09b8046d4 Allocated by task 3399: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x161/0x7a0 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] tomoyo_realpath_from_path+0xc2/0x620 security/tomoyo/realpath.c:252 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x214/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xeb/0x150 security/security.c:1273 vfs_getattr+0x22/0x60 fs/stat.c:117 vfs_statx+0x142/0x1e0 fs/stat.c:201 vfs_lstat include/linux/fs.h:3284 [inline] __do_sys_newlstat+0x96/0x120 fs/stat.c:364 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 3399: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 tomoyo_realpath_from_path+0x18f/0x620 security/tomoyo/realpath.c:289 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x214/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xeb/0x150 security/security.c:1273 vfs_getattr+0x22/0x60 fs/stat.c:117 vfs_statx+0x142/0x1e0 fs/stat.c:201 vfs_lstat include/linux/fs.h:3284 [inline] __do_sys_newlstat+0x96/0x120 fs/stat.c:364 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff88805c16e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3985 bytes inside of 4096-byte region [ffff88805c16e000, ffff88805c16f000) The buggy address belongs to the page: page:ffffea0001705b80 refcount:1 mapcount:0 mapping:00000000b01fceaf index:0x0 head:ffffea0001705b80 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea000255b608 ffffea000143de08 ffff8880aa002000 raw: 0000000000000000 ffff88805c16e000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805c16ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805c16ef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805c16ef80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805c16f000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805c16f080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================