================================================================== BUG: KASAN: use-after-free in __xfrm_policy_bysel_ctx.constprop.0+0x3e5/0x470 net/xfrm/xfrm_policy.c:1618 Read of size 1 at addr ffff888067438699 by task syz-executor4/9139 CPU: 1 PID: 9139 Comm: syz-executor4 Not tainted 5.0.0-rc3+ #24 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+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132 __xfrm_policy_bysel_ctx.constprop.0+0x3e5/0x470 net/xfrm/xfrm_policy.c:1618 xfrm_policy_bysel_ctx+0x944/0x1020 net/xfrm/xfrm_policy.c:1664 xfrm_get_policy+0x67b/0x1160 net/xfrm/xfrm_user.c:1887 xfrm_user_rcv_msg+0x458/0x8d0 net/xfrm/xfrm_user.c:2663 netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2485 xfrm_netlink_rcv+0x70/0x90 net/xfrm/xfrm_user.c:2671 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1925 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116 __sys_sendmsg+0x112/0x270 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+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007feb37e37c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007feb37e386d4 R13: 00000000004c56af R14: 00000000004d9420 R15: 00000000ffffffff Allocated by task 9084: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 __do_kmalloc_node mm/slab.c:3673 [inline] __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3687 __kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:140 __alloc_skb+0x12d/0x730 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1011 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline] netlink_sendmsg+0xb11/0xf90 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 sock_write_iter+0x379/0x5e0 net/socket.c:900 call_write_iter include/linux/fs.h:1862 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x764/0xb40 fs/read_write.c:487 vfs_write+0x20c/0x580 fs/read_write.c:549 ksys_write+0x105/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9084: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 skb_free_head+0x93/0xb0 net/core/skbuff.c:553 skb_release_data+0x6ea/0x970 net/core/skbuff.c:573 skb_release_all+0x4d/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb net/core/skbuff.c:701 [inline] consume_skb+0x18c/0x550 net/core/skbuff.c:695 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline] netlink_unicast+0x57c/0x770 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1925 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 sock_write_iter+0x379/0x5e0 net/socket.c:900 call_write_iter include/linux/fs.h:1862 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x764/0xb40 fs/read_write.c:487 vfs_write+0x20c/0x580 fs/read_write.c:549 ksys_write+0x105/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888067438480 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 537 bytes inside of 1024-byte region [ffff888067438480, ffff888067438880) The buggy address belongs to the page: page:ffffea00019d0e00 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0xffff888067438900 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00027e2b08 ffffea0002923d08 ffff88812c3f0ac0 raw: ffff888067438900 ffff888067438000 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888067438580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888067438600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888067438680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888067438700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888067438780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================