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: use-after-free in nla_strlcpy+0x13d/0x150 lib/nlattr.c:314 Read of size 1 at addr ffff8801a910fb5d by task syz-executor170/4513 CPU: 1 PID: 4513 Comm: syz-executor170 Not tainted 4.17.0-rc6+ #68 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: 0033:0x4400e9 RSP: 002b:00007fff17c18608 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fff17c18630 RCX: 00000000004400e9 RDX: 000000000000001f RSI: 0000000020390000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007fff17c18680 R09: 00007fff17c18680 R10: 00007fff17c18680 R11: 0000000000000246 R12: 0000000000401a10 R13: 0000000000401aa0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4513: 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 __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:517 [inline] load_elf_phdrs+0x17a/0x250 fs/binfmt_elf.c:441 load_elf_binary+0x32b/0x5610 fs/binfmt_elf.c:737 search_binary_handler+0x17d/0x570 fs/exec.c:1653 exec_binprm fs/exec.c:1695 [inline] do_execveat_common.isra.34+0x16ce/0x2590 fs/exec.c:1817 do_execve fs/exec.c:1862 [inline] __do_sys_execve fs/exec.c:1943 [inline] __se_sys_execve fs/exec.c:1938 [inline] __x64_sys_execve+0x8d/0xb0 fs/exec.c:1938 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4513: 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] kfree+0xd9/0x260 mm/slab.c:3813 load_elf_binary+0x2569/0x5610 fs/binfmt_elf.c:1118 search_binary_handler+0x17d/0x570 fs/exec.c:1653 exec_binprm fs/exec.c:1695 [inline] do_execveat_common.isra.34+0x16ce/0x2590 fs/exec.c:1817 do_execve fs/exec.c:1862 [inline] __do_sys_execve fs/exec.c:1943 [inline] __se_sys_execve fs/exec.c:1938 [inline] __x64_sys_execve+0x8d/0xb0 fs/exec.c:1938 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 ffff8801a910fac0 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 157 bytes inside of 512-byte region [ffff8801a910fac0, ffff8801a910fcc0) The buggy address belongs to the page: page:ffffea0006a443c0 count:1 mapcount:0 mapping:ffff8801a910f0c0 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801a910f0c0 0000000000000000 0000000100000006 raw: ffffea0006b48e60 ffff8801da801748 ffff8801da800940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801a910fa00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801a910fa80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8801a910fb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801a910fb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801a910fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================