svn commit: r225827 - head/sys/kern head/usr.bin/compress head/usr.bin/gzip releng/7.3 releng/7.3/sys/conf releng/7.3/sys/kern releng/7.3/usr.bin/compress releng/7.3/usr.bin/gzip releng/7.4 releng/...

Alexander Best arundel at freebsd.org
Fri Sep 30 08:16:31 UTC 2011


On Wed Sep 28 11, Bjoern A. Zeeb wrote:
> Author: bz
> Date: Wed Sep 28 08:47:17 2011
> New Revision: 225827
> URL: http://svn.freebsd.org/changeset/base/225827
> 
> Log:
>   Fix handling of corrupt compress(1)ed data. [11:04]

a thread on freebsd-questions@ indicates that the changes to uipc_usrreq.c
broke support for flash.

the thread's subject line is "FreeBSD 9-Beta3 and FlashPlayer".

cheers.
alex

>   
>   Add missing length checks on unix socket addresses. [11:05]
>   
>   Approved by:	so (cperciva)
>   Approved by:	re (kensmith)
>   Security:	FreeBSD-SA-11:04.compress
>   Security:	CVE-2011-2895 [11:04]
>   Security:	FreeBSD-SA-11:05.unix
> 
> Modified:
>   head/sys/kern/uipc_usrreq.c
>   head/usr.bin/compress/zopen.c
>   head/usr.bin/gzip/zuncompress.c
> 
> Changes in other areas also in this revision:
> Modified:
>   releng/7.3/UPDATING
>   releng/7.3/sys/conf/newvers.sh
>   releng/7.3/sys/kern/uipc_usrreq.c
>   releng/7.3/usr.bin/compress/zopen.c
>   releng/7.3/usr.bin/gzip/zuncompress.c
>   releng/7.4/UPDATING
>   releng/7.4/sys/conf/newvers.sh
>   releng/7.4/sys/kern/uipc_usrreq.c
>   releng/7.4/usr.bin/compress/zopen.c
>   releng/7.4/usr.bin/gzip/zuncompress.c
>   releng/8.1/UPDATING
>   releng/8.1/sys/conf/newvers.sh
>   releng/8.1/sys/kern/uipc_usrreq.c
>   releng/8.1/usr.bin/compress/zopen.c
>   releng/8.1/usr.bin/gzip/zuncompress.c
>   releng/8.2/UPDATING
>   releng/8.2/sys/conf/newvers.sh
>   releng/8.2/sys/kern/uipc_usrreq.c
>   releng/8.2/usr.bin/compress/zopen.c
>   releng/8.2/usr.bin/gzip/zuncompress.c
>   stable/7/sys/kern/uipc_usrreq.c
>   stable/7/usr.bin/compress/zopen.c
>   stable/7/usr.bin/gzip/zuncompress.c
>   stable/8/sys/kern/uipc_usrreq.c
>   stable/8/usr.bin/compress/zopen.c
>   stable/8/usr.bin/gzip/zuncompress.c
>   stable/9/sys/kern/uipc_usrreq.c
>   stable/9/usr.bin/compress/zopen.c
>   stable/9/usr.bin/gzip/zuncompress.c
> 
> Modified: head/sys/kern/uipc_usrreq.c
> ==============================================================================
> --- head/sys/kern/uipc_usrreq.c	Wed Sep 28 08:19:45 2011	(r225826)
> +++ head/sys/kern/uipc_usrreq.c	Wed Sep 28 08:47:17 2011	(r225827)
> @@ -462,6 +462,8 @@ uipc_bind(struct socket *so, struct sock
>  	unp = sotounpcb(so);
>  	KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
>  
> +	if (soun->sun_len > sizeof(struct sockaddr_un))
> +		return (EINVAL);
>  	namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
>  	if (namelen <= 0)
>  		return (EINVAL);
> @@ -1252,6 +1254,8 @@ unp_connect(struct socket *so, struct so
>  	unp = sotounpcb(so);
>  	KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
>  
> +	if (nam->sa_len > sizeof(struct sockaddr_un))
> +		return (EINVAL);
>  	len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
>  	if (len <= 0)
>  		return (EINVAL);
> 
> Modified: head/usr.bin/compress/zopen.c
> ==============================================================================
> --- head/usr.bin/compress/zopen.c	Wed Sep 28 08:19:45 2011	(r225826)
> +++ head/usr.bin/compress/zopen.c	Wed Sep 28 08:47:17 2011	(r225827)
> @@ -486,7 +486,7 @@ zread(void *cookie, char *rbp, int num)
>  	block_compress = maxbits & BLOCK_MASK;
>  	maxbits &= BIT_MASK;
>  	maxmaxcode = 1L << maxbits;
> -	if (maxbits > BITS) {
> +	if (maxbits > BITS || maxbits < 12) {
>  		errno = EFTYPE;
>  		return (-1);
>  	}
> @@ -513,17 +513,28 @@ zread(void *cookie, char *rbp, int num)
>  			for (code = 255; code >= 0; code--)
>  				tab_prefixof(code) = 0;
>  			clear_flg = 1;
> -			free_ent = FIRST - 1;
> -			if ((code = getcode(zs)) == -1)	/* O, untimely death! */
> -				break;
> +			free_ent = FIRST;
> +			oldcode = -1;
> +			continue;
>  		}
>  		incode = code;
>  
> -		/* Special case for KwKwK string. */
> +		/* Special case for kWkWk string. */
>  		if (code >= free_ent) {
> +			if (code > free_ent || oldcode == -1) {
> +				/* Bad stream. */
> +				errno = EINVAL;
> +				return (-1);
> +			}
>  			*stackp++ = finchar;
>  			code = oldcode;
>  		}
> +		/*
> +		 * The above condition ensures that code < free_ent.
> +		 * The construction of tab_prefixof in turn guarantees that
> +		 * each iteration decreases code and therefore stack usage is
> +		 * bound by 1 << BITS - 256.
> +		 */
>  
>  		/* Generate output characters in reverse order. */
>  		while (code >= 256) {
> @@ -540,7 +551,7 @@ middle:		do {
>  		} while (stackp > de_stack);
>  
>  		/* Generate the new entry. */
> -		if ((code = free_ent) < maxmaxcode) {
> +		if ((code = free_ent) < maxmaxcode && oldcode != -1) {
>  			tab_prefixof(code) = (u_short) oldcode;
>  			tab_suffixof(code) = finchar;
>  			free_ent = code + 1;
> 
> Modified: head/usr.bin/gzip/zuncompress.c
> ==============================================================================
> --- head/usr.bin/gzip/zuncompress.c	Wed Sep 28 08:19:45 2011	(r225826)
> +++ head/usr.bin/gzip/zuncompress.c	Wed Sep 28 08:47:17 2011	(r225827)
> @@ -247,7 +247,7 @@ zread(void *cookie, char *rbp, int num)
>  	zs->zs_block_compress = zs->zs_maxbits & BLOCK_MASK;
>  	zs->zs_maxbits &= BIT_MASK;
>  	zs->zs_maxmaxcode = 1L << zs->zs_maxbits;
> -	if (zs->zs_maxbits > BITS) {
> +	if (zs->zs_maxbits > BITS || zs->zs_maxbits < 12) {
>  		errno = EFTYPE;
>  		return (-1);
>  	}
> @@ -259,13 +259,7 @@ zread(void *cookie, char *rbp, int num)
>  	}
>  	zs->zs_free_ent = zs->zs_block_compress ? FIRST : 256;
>  
> -	zs->u.r.zs_finchar = zs->u.r.zs_oldcode = getcode(zs);
> -	if (zs->u.r.zs_oldcode == -1)	/* EOF already? */
> -		return (0);	/* Get out of here */
> -
> -	/* First code must be 8 bits = char. */
> -	*bp++ = (u_char)zs->u.r.zs_finchar;
> -	count--;
> +	zs->u.r.zs_oldcode = -1;
>  	zs->u.r.zs_stackp = de_stack;
>  
>  	while ((zs->u.r.zs_code = getcode(zs)) > -1) {
> @@ -275,17 +269,29 @@ zread(void *cookie, char *rbp, int num)
>  			    zs->u.r.zs_code--)
>  				tab_prefixof(zs->u.r.zs_code) = 0;
>  			zs->zs_clear_flg = 1;
> -			zs->zs_free_ent = FIRST - 1;
> -			if ((zs->u.r.zs_code = getcode(zs)) == -1)	/* O, untimely death! */
> -				break;
> +			zs->zs_free_ent = FIRST;
> +			zs->u.r.zs_oldcode = -1;
> +			continue;
>  		}
>  		zs->u.r.zs_incode = zs->u.r.zs_code;
>  
>  		/* Special case for KwKwK string. */
>  		if (zs->u.r.zs_code >= zs->zs_free_ent) {
> +			if (zs->u.r.zs_code > zs->zs_free_ent ||
> +			    zs->u.r.zs_oldcode == -1) {
> +				/* Bad stream. */
> +				errno = EINVAL;
> +				return (-1);
> +			}
>  			*zs->u.r.zs_stackp++ = zs->u.r.zs_finchar;
>  			zs->u.r.zs_code = zs->u.r.zs_oldcode;
>  		}
> +		/*
> +		 * The above condition ensures that code < free_ent.
> +		 * The construction of tab_prefixof in turn guarantees that
> +		 * each iteration decreases code and therefore stack usage is
> +		 * bound by 1 << BITS - 256.
> +		 */
>  
>  		/* Generate output characters in reverse order. */
>  		while (zs->u.r.zs_code >= 256) {
> @@ -302,7 +308,8 @@ middle:		do {
>  		} while (zs->u.r.zs_stackp > de_stack);
>  
>  		/* Generate the new entry. */
> -		if ((zs->u.r.zs_code = zs->zs_free_ent) < zs->zs_maxmaxcode) {
> +		if ((zs->u.r.zs_code = zs->zs_free_ent) < zs->zs_maxmaxcode &&
> +		    zs->u.r.zs_oldcode != -1) {
>  			tab_prefixof(zs->u.r.zs_code) = (u_short) zs->u.r.zs_oldcode;
>  			tab_suffixof(zs->u.r.zs_code) = zs->u.r.zs_finchar;
>  			zs->zs_free_ent = zs->u.r.zs_code + 1;


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