audit: type=1804 audit(1545437312.629:297): pid=2934 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor3" name="/root/syzkaller-testdir814138728/syzkaller.MxwyQv/2658/memory.events" dev="sda1" ino=16517 res=1 ================================================================== BUG: KASAN: use-after-free in xfrm_policy_insert_list+0xd7f/0x1020 net/xfrm/xfrm_policy.c:1532 Read of size 1 at addr ffff8881cc1d78d9 by task syz-executor4/3002 CPU: 0 PID: 3002 Comm: syz-executor4 Not tainted 4.20.0-rc7+ #357 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 xfrm_policy_insert_list+0xd7f/0x1020 net/xfrm/xfrm_policy.c:1532 xfrm_policy_inexact_insert+0x166/0xee0 net/xfrm/xfrm_policy.c:1195 xfrm_policy_insert+0x639/0x850 net/xfrm/xfrm_policy.c:1570 xfrm_add_policy+0x2a0/0x6f0 net/xfrm/xfrm_user.c:1657 xfrm_user_rcv_msg+0x44c/0x8e0 net/xfrm/xfrm_user.c:2663 netlink_rcv_skb+0x16c/0x430 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2671 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x59f/0x750 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f58acdb1c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 000000002014f000 RDI: 0000000000000003 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f58acdb26d4 R13: 00000000004c44d8 R14: 00000000004d74e8 R15: 00000000ffffffff Allocated by task 5918: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:546 [inline] syslog_print kernel/printk/printk.c:1301 [inline] do_syslog+0xb9b/0x1690 kernel/printk/printk.c:1469 kmsg_read+0x8f/0xc0 fs/proc/kmsg.c:40 proc_reg_read+0x2a3/0x3d0 fs/proc/inode.c:231 __vfs_read+0x117/0x9b0 fs/read_write.c:416 vfs_read+0x17f/0x3c0 fs/read_write.c:452 ksys_read+0x101/0x260 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 5918: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 syslog_print kernel/printk/printk.c:1352 [inline] do_syslog+0x147b/0x1690 kernel/printk/printk.c:1469 kmsg_read+0x8f/0xc0 fs/proc/kmsg.c:40 proc_reg_read+0x2a3/0x3d0 fs/proc/inode.c:231 __vfs_read+0x117/0x9b0 fs/read_write.c:416 vfs_read+0x17f/0x3c0 fs/read_write.c:452 ksys_read+0x101/0x260 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881cc1d76c0 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 537 bytes inside of 1024-byte region [ffff8881cc1d76c0, ffff8881cc1d7ac0) The buggy address belongs to the page: page:ffffea0007307580 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0xffff8881cc1d6dc0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea000748b408 ffffea000647fe08 ffff8881da800ac0 raw: ffff8881cc1d6dc0 ffff8881cc1d6040 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881cc1d7780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cc1d7800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881cc1d7880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881cc1d7900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cc1d7980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================