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Revision b095884a58876ccd3e65f620b7f80d61b4bce687 authored by Matt Caswell on 07 January 2015, 14:18:13 UTC, committed by Matt Caswell on 08 January 2015, 14:14:56 UTC
A memory leak can occur in dtls1_buffer_record if either of the calls to
ssl3_setup_buffers or pqueue_insert fail. The former will fail if there is a
malloc failure, whilst the latter will fail if attempting to add a duplicate
record to the queue. This should never happen because duplicate records should
be detected and dropped before any attempt to add them to the queue.
Unfortunately records that arrive that are for the next epoch are not being
recorded correctly, and therefore replays are not being detected.
Additionally, these "should not happen" failures that can occur in
dtls1_buffer_record are not being treated as fatal and therefore an attacker
could exploit this by sending repeated replay records for the next epoch,
eventually causing a DoS through memory exhaustion.

Thanks to Chris Mueller for reporting this issue and providing initial
analysis and a patch. Further analysis and the final patch was performed by
Matt Caswell from the OpenSSL development team.

CVE-2015-0206

Reviewed-by: Dr Stephen Henson <steve@openssl.org>
(cherry picked from commit 652ff0f4796eecd8729b4690f2076d1c7ccb2862)
1 parent f7fe3d2
Raw File
sgiccbug.c
/* NOCW */
/* sgibug.c */
/* bug found by Eric Young (eay@mincom.oz.au) May 95 */

#include <stdio.h>

/* This compiler bug it present on IRIX 5.3, 5.1 and 4.0.5 (these are
 * the only versions of IRIX I have access to.
 * defining FIXBUG removes the bug.
 * (bug is still present in IRIX 6.3 according to
 * Gage <agage@forgetmenot.Mines.EDU>
 */
 
/* Compare the output from
 * cc sgiccbug.c; ./a.out
 * and
 * cc -O sgiccbug.c; ./a.out
 */

static unsigned long a[4]={0x01234567,0x89ABCDEF,0xFEDCBA98,0x76543210};
static unsigned long b[4]={0x89ABCDEF,0xFEDCBA98,0x76543210,0x01234567};
static unsigned long c[4]={0x77777778,0x8ACF1357,0x88888888,0x7530ECA9};

main()
	{
	unsigned long r[4];
	sub(r,a,b);
	fprintf(stderr,"input a= %08X %08X %08X %08X\n",a[3],a[2],a[1],a[0]);
	fprintf(stderr,"input b= %08X %08X %08X %08X\n",b[3],b[2],b[1],b[0]);
	fprintf(stderr,"output = %08X %08X %08X %08X\n",r[3],r[2],r[1],r[0]);
	fprintf(stderr,"correct= %08X %08X %08X %08X\n",c[3],c[2],c[1],c[0]);
	}

int sub(r,a,b)
unsigned long *r,*a,*b;
	{
	register unsigned long t1,t2,*ap,*bp,*rp;
	int i,carry;
#ifdef FIXBUG
	unsigned long dummy;
#endif

	ap=a;
	bp=b;
	rp=r;
	carry=0;
	for (i=0; i<4; i++)
		{
		t1= *(ap++);
		t2= *(bp++);
		t1=(t1-t2);
#ifdef FIXBUG
		dummy=t1;
#endif
		*(rp++)=t1&0xffffffff;
		}
	}
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