================================================================== BUG: KASAN: use-after-free in xfrm_policy_insert_inexact_list net/xfrm/xfrm_policy.c:1497 [inline] BUG: KASAN: use-after-free in xfrm_policy_inexact_insert+0xcd1/0xee0 net/xfrm/xfrm_policy.c:1202 Read of size 1 at addr ffff8881bcb40fd9 by task syz-executor2/8108 CPU: 1 PID: 8108 Comm: syz-executor2 Not tainted 4.20.0-rc7+ #360 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+0x1d3/0x2c6 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 xfrm_policy_insert_inexact_list net/xfrm/xfrm_policy.c:1497 [inline] xfrm_policy_inexact_insert+0xcd1/0xee0 net/xfrm/xfrm_policy.c:1202 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: 0033:0x457759 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:00007f93fa693c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457759 RDX: 0000000000000000 RSI: 000000002014f000 RDI: 0000000000000005 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f93fa6946d4 R13: 00000000004c4a19 R14: 00000000004d8100 R15: 00000000ffffffff Allocated by task 9056: 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 __do_kmalloc mm/slab.c:3722 [inline] __kmalloc+0x15b/0x770 mm/slab.c:3731 kmalloc_array include/linux/slab.h:669 [inline] kcalloc include/linux/slab.h:680 [inline] alloc_pipe_info+0x2ce/0x5d0 fs/pipe.c:650 get_pipe_inode fs/pipe.c:712 [inline] create_pipe_files+0x91/0x720 fs/pipe.c:744 __do_pipe_flags+0x45/0x250 fs/pipe.c:781 do_pipe2+0x9d/0x310 fs/pipe.c:829 __do_sys_pipe2 fs/pipe.c:847 [inline] __se_sys_pipe2 fs/pipe.c:845 [inline] __x64_sys_pipe2+0x54/0x80 fs/pipe.c:845 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9056: 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 free_pipe_info+0x24b/0x300 fs/pipe.c:683 put_pipe_info+0xd0/0xf0 fs/pipe.c:556 pipe_release+0x1de/0x270 fs/pipe.c:577 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881bcb40dc0 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 537 bytes inside of 1024-byte region [ffff8881bcb40dc0, ffff8881bcb411c0) The buggy address belongs to the page: page:ffffea0006f2d000 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006fb8788 ffffea0006684e88 ffff8881da800ac0 raw: 0000000000000000 ffff8881bcb40040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881bcb40e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881bcb40f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881bcb40f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881bcb41000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881bcb41080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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