Fix ASan buffer overflow errors caused by memcmp (#393)

JohnoKing · web-flow · commit d40d998e3a35 · 2021-12-22T06:33:36.000Z
This commit replaces more instances of memcmp with strncmp to fix some more heap-buffer-overflow errors in ASan, some of which can occur when running the regression tests with xtrace enabled. It combines two existing patches plus another fix in name.c for xtrace: https://www.mail-archive.com/ast-developers@lists.research.att.com/msg00877.html https://github.com/oracle/solaris-userland/blob/master/components/ksh93/patches/035-CR7036535.patch
diff --git a/src/cmd/ksh93/sh/name.c b/src/cmd/ksh93/sh/name.c
@@ -192,7 +192,7 @@ Namval_t *nv_addnode(Namval_t* np, int remove)
 	{
 		name = (sp->nodes[0])->nvname;
 		i = strlen(name);
-		if(memcmp(np->nvname,name,i))
+		if(strncmp(np->nvname,name,i))
 			return(np);
 	}
 	if(sp->rp && sp->numnodes)
diff --git a/src/cmd/ksh93/sh/nvtree.c b/src/cmd/ksh93/sh/nvtree.c
@@ -860,7 +860,7 @@ static char **genvalue(char **argv, const char *prefix, int n, struct Walk *wp)
 					continue;
 				break;
 			}
-			else if(outfile && !wp->nofollow && argv[1] && memcmp(arg,argv[1],l=strlen(arg))==0 && argv[1][l]=='[')
+			else if(outfile && !wp->nofollow && argv[1] && strncmp(arg,argv[1],l=strlen(arg))==0 && argv[1][l]=='[')
 			{
 				int	k=1;
 				Namarr_t *ap=0;
diff --git a/src/cmd/ksh93/sh/nvtype.c b/src/cmd/ksh93/sh/nvtype.c
@@ -1053,7 +1053,7 @@ Namval_t *nv_mktype(Namval_t **nodes, int numnodes)
 			np->nvenv = 0;
 		}
 		nq->nvname = cp;
-		if(name && memcmp(name,&np->nvname[m],n)==0 && np->nvname[m+n]=='.')
+		if(name && strncmp(name,&np->nvname[m],n)==0 && np->nvname[m+n]=='.')
 			offset -= sizeof(char*);
 		dsize = nv_datasize(np,&offset);
 		cp = strcopy(name=cp, &np->nvname[m]);
diff --git a/src/cmd/ksh93/sh/path.c b/src/cmd/ksh93/sh/path.c
@@ -1526,7 +1526,7 @@ static Pathcomp_t *path_addcomp(Shell_t *shp,Pathcomp_t *first, Pathcomp_t *old,
 		len = strlen(name);
 	for(pp=first; pp; pp=pp->next)
 	{
-		if(len == pp->len && memcmp(name,pp->name,len)==0)
+		if(len == pp->len && strncmp(name,pp->name,len)==0)
 		{
 			pp->flags |= flag;
 			return(first);
@@ -1817,7 +1817,7 @@ Pathcomp_t *path_dirfind(Pathcomp_t *first,const char *name,int c)
 	register Pathcomp_t *pp=first;
 	while(pp)
 	{
-		if(memcmp(name,pp->name,pp->len)==0 && name[pp->len]==c) 
+		if(strncmp(name,pp->name,pp->len)==0 && name[pp->len]==c)
 			return(pp);
 		pp = pp->next;
 	}

Original file line number	Diff line number	Diff line change
`@@ -192,7 +192,7 @@ Namval_t nv_addnode(Namval_t np, int remove)`
`192`	`192`	`{`
`193`	`193`	`name = (sp->nodes[0])->nvname;`
`194`	`194`	`i = strlen(name);`
`195`		`- if(memcmp(np->nvname,name,i))`
	`195`	`+ if(strncmp(np->nvname,name,i))`
`196`	`196`	`return(np);`
`197`	`197`	`}`
`198`	`198`	`if(sp->rp && sp->numnodes)`
Original file line number	Diff line number	Diff line change
`@@ -860,7 +860,7 @@ static char genvalue(char argv, const char prefix, int n, struct Walk wp)`
`860`	`860`	`continue;`
`861`	`861`	`break;`
`862`	`862`	`}`
`863`		`- else if(outfile && !wp->nofollow && argv[1] && memcmp(arg,argv[1],l=strlen(arg))==0 && argv[1][l]=='[')`
	`863`	`+ else if(outfile && !wp->nofollow && argv[1] && strncmp(arg,argv[1],l=strlen(arg))==0 && argv[1][l]=='[')`
`864`	`864`	`{`
`865`	`865`	`int k=1;`
`866`	`866`	`Namarr_t *ap=0;`
Original file line number	Diff line number	Diff line change
`@@ -1053,7 +1053,7 @@ Namval_t nv_mktype(Namval_t *nodes, int numnodes)`
`1053`	`1053`	`np->nvenv = 0;`
`1054`	`1054`	`}`
`1055`	`1055`	`nq->nvname = cp;`
`1056`		`- if(name && memcmp(name,&np->nvname[m],n)==0 && np->nvname[m+n]=='.')`
	`1056`	`+ if(name && strncmp(name,&np->nvname[m],n)==0 && np->nvname[m+n]=='.')`
`1057`	`1057`	`offset -= sizeof(char*);`
`1058`	`1058`	`dsize = nv_datasize(np,&offset);`
`1059`	`1059`	`cp = strcopy(name=cp, &np->nvname[m]);`
Original file line number	Diff line number	Diff line change
`@@ -1526,7 +1526,7 @@ static Pathcomp_t path_addcomp(Shell_t shp,Pathcomp_t first, Pathcomp_t old,`
`1526`	`1526`	`len = strlen(name);`
`1527`	`1527`	`for(pp=first; pp; pp=pp->next)`
`1528`	`1528`	`{`
`1529`		`- if(len == pp->len && memcmp(name,pp->name,len)==0)`
	`1529`	`+ if(len == pp->len && strncmp(name,pp->name,len)==0)`
`1530`	`1530`	`{`
`1531`	`1531`	`pp->flags \|= flag;`
`1532`	`1532`	`return(first);`
`@@ -1817,7 +1817,7 @@ Pathcomp_t path_dirfind(Pathcomp_t first,const char *name,int c)`
`1817`	`1817`	`register Pathcomp_t *pp=first;`
`1818`	`1818`	`while(pp)`
`1819`	`1819`	`{`
`1820`		`- if(memcmp(name,pp->name,pp->len)==0 && name[pp->len]==c)`
	`1820`	`+ if(strncmp(name,pp->name,pp->len)==0 && name[pp->len]==c)`
`1821`	`1821`	`return(pp);`
`1822`	`1822`	`pp = pp->next;`
`1823`	`1823`	`}`