random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ================================================================== BUG: KASAN: slab-out-of-bounds in nla_strlcpy+0x13d/0x150 lib/nlattr.c:314 Read of size 1 at addr ffff8801acb8451d by task syz-executor834/4496 CPU: 0 PID: 4496 Comm: syz-executor834 Not tainted 4.17.0-rc6+ #62 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+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 nla_strlcpy+0x13d/0x150 lib/nlattr.c:314 nfnl_acct_new+0x574/0xc50 net/netfilter/nfnetlink_acct.c:118 nfnetlink_rcv_msg+0xdb5/0xff0 net/netfilter/nfnetlink.c:212 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448 nfnetlink_rcv+0x1fe/0x1ba0 net/netfilter/nfnetlink.c:513 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 sock_write_iter+0x35a/0x5a0 net/socket.c:908 call_write_iter include/linux/fs.h:1784 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x64d/0x960 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 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+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43fcf9 RSP: 002b:00007fff83e9ee78 EFLAGS: 00000213 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fcf9 RDX: 000000000000001f RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000401620 R13: 00000000004016b0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 2836: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 getname_flags+0xd0/0x5a0 fs/namei.c:140 getname+0x19/0x20 fs/namei.c:211 do_sys_open+0x39a/0x740 fs/open.c:1087 __do_sys_open fs/open.c:1111 [inline] __se_sys_open fs/open.c:1106 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1106 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 2836: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 putname+0xf2/0x130 fs/namei.c:261 do_sys_open+0x554/0x740 fs/open.c:1102 __do_sys_open fs/open.c:1111 [inline] __se_sys_open fs/open.c:1106 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1106 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801acb849c0 which belongs to the cache names_cache of size 4096 The buggy address is located 1187 bytes to the left of 4096-byte region [ffff8801acb849c0, ffff8801acb859c0) The buggy address belongs to the page: page:ffffea0006b2e100 count:1 mapcount:0 mapping:ffff8801acb849c0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801acb849c0 0000000000000000 0000000100000001 raw: ffffea0006b2f2a0 ffffea0006b2e6a0 ffff8801da988dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801acb84400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801acb84480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801acb84500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801acb84580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801acb84600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================