sh: Fix possible memory leaks and double frees with unexpected SIGINT.

bin/sh/alias.c

@@ -180,6 +180,7 @@ printaliases(void)
 	int i, j;
 	struct alias **sorted, *ap;
 
+	INTOFF;
 	sorted = ckmalloc(aliases * sizeof(*sorted));
 	j = 0;
 	for (i = 0; i < ATABSIZE; i++)
@@ -187,9 +188,13 @@ printaliases(void)
 			if (*ap->name != '\0')
 				sorted[j++] = ap;
 	qsort(sorted, aliases, sizeof(*sorted), comparealiases);
-	for (i = 0; i < aliases; i++)
+	for (i = 0; i < aliases; i++) {
 		printalias(sorted[i]);
+		if (int_pending())
+			break;
+	}
 	ckfree(sorted);
+	INTON;
 }
 
 int

bin/sh/exec.c

@@ -612,6 +612,7 @@ defun(const char *name, union node *func)
 
 /*
  * Delete a function if it exists.
+ * Called with interrupts off.
  */
 
 int

bin/sh/expand.c

@@ -956,6 +956,7 @@ recordregion(int start, int end, int inquotes)
 {
 	struct ifsregion *ifsp;
 
+	INTOFF;
 	if (ifslastp == NULL) {
 		ifsp = &ifsfirst;
 	} else {
@@ -963,6 +964,7 @@ recordregion(int start, int end, int inquotes)
 		    && ifslastp->inquotes == inquotes) {
 			/* extend previous area */
 			ifslastp->endoff = end;
+			INTON;
 			return;
 		}
 		ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
@@ -973,6 +975,7 @@ recordregion(int start, int end, int inquotes)
 	ifslastp->begoff = start;
 	ifslastp->endoff = end;
 	ifslastp->inquotes = inquotes;
+	INTON;
 }
 
 

bin/sh/redir.c

@@ -92,6 +92,13 @@ static int openhere(union node *);
  * undone by calling popredir.  If the REDIR_BACKQ flag is set, then the
  * standard output, and the standard error if it becomes a duplicate of
  * stdout, is saved in memory.
+*
+ * We suppress interrupts so that we won't leave open file
+ * descriptors around.  Because the signal handler remains
+ * installed and we do not use system call restart, interrupts
+ * will still abort blocking opens such as fifos (they will fail
+ * with EINTR). There is, however, a race condition if an interrupt
+ * arrives after INTOFF and before open blocks.
  */
 
 void
@@ -103,6 +110,7 @@ redirect(union node *redir, int flags)
 	int fd;
 	char memory[10];	/* file descriptors to write to memory */
 
+	INTOFF;
 	for (i = 10 ; --i >= 0 ; )
 		memory[i] = 0;
 	memory[1] = flags & REDIR_BACKQ;
@@ -139,11 +147,14 @@ redirect(union node *redir, int flags)
 			INTON;
 		}
 		openredirect(n, memory);
+		INTON;
+		INTOFF;
 	}
 	if (memory[1])
 		out1 = &memout;
 	if (memory[2])
 		out2 = &memout;
+	INTON;
 }
 
 
@@ -156,15 +167,6 @@ openredirect(union node *redir, char memory[10])
 	int f;
 	int e;
 
-	/*
-	 * We suppress interrupts so that we won't leave open file
-	 * descriptors around.  Because the signal handler remains
-	 * installed and we do not use system call restart, interrupts
-	 * will still abort blocking opens such as fifos (they will fail
-	 * with EINTR). There is, however, a race condition if an interrupt
-	 * arrives after INTOFF and before open blocks.
-	 */
-	INTOFF;
 	memory[fd] = 0;
 	switch (redir->nfile.type) {
 	case NFROM:
@@ -237,7 +239,6 @@ openredirect(union node *redir, char memory[10])
 	default:
 		abort();
 	}
-	INTON;
 }
 
 

bin/sh/var.c

@@ -249,6 +249,7 @@ setvar(const char *name, const char *val, int flags)
 		vallen = strlen(val);
 		len += vallen;
 	}
+	INTOFF;
 	nameeq = ckmalloc(len);
 	memcpy(nameeq, name, namelen);
 	nameeq[namelen] = '=';
@@ -257,6 +258,7 @@ setvar(const char *name, const char *val, int flags)
 	else
 		nameeq[namelen + 1] = '\0';
 	setvareq(nameeq, flags);
+	INTON;
 }
 
 static int
@@ -289,6 +291,7 @@ change_env(const char *s, int set)
 	char *eqp;
 	char *ss;
 
+	INTOFF;
 	ss = savestr(s);
 	if ((eqp = strchr(ss, '=')) != NULL)
 		*eqp = '\0';
@@ -297,6 +300,7 @@ change_env(const char *s, int set)
 	else
 		(void) unsetenv(ss);
 	ckfree(ss);
+	INTON;
 
 	return;
 }
@@ -359,13 +363,13 @@ setvareq(char *s, int flags)
 	/* not found */
 	if (flags & VNOSET)
 		return;
+	INTOFF;
 	vp = ckmalloc(sizeof (*vp));
 	vp->flags = flags;
 	vp->text = s;
 	vp->name_len = nlen;
 	vp->next = *vpp;
 	vp->func = NULL;
-	INTOFF;
 	*vpp = vp;
 	if ((vp->flags & VEXPORT) && localevar(s)) {
 		change_env(s, 1);
@@ -773,6 +777,7 @@ poplocalvars(void)
 	struct localvar *lvp;
 	struct var *vp;
 
+	INTOFF;
 	while ((lvp = localvars) != NULL) {
 		localvars = lvp->next;
 		vp = lvp->vp;
@@ -790,6 +795,7 @@ poplocalvars(void)
 		}
 		ckfree(lvp);
 	}
+	INTON;
 }
 
 
@@ -828,18 +834,21 @@ unsetcmd(int argc __unused, char **argv __unused)
 	if (flg_func == 0 && flg_var == 0)
 		flg_var = 1;
 
+	INTOFF;
 	for (ap = argptr; *ap ; ap++) {
 		if (flg_func)
 			ret |= unsetfunc(*ap);
 		if (flg_var)
 			ret |= unsetvar(*ap);
 	}
+	INTON;
 	return ret;
 }
 
 
 /*
  * Unset the specified variable.
+ * Called with interrupts off.
  */
 
 int
@@ -853,7 +862,6 @@ unsetvar(const char *s)
 		return (0);
 	if (vp->flags & VREADONLY)
 		return (1);
-	INTOFF;
 	if (vp->text[vp->name_len + 1] != '\0')
 		setvar(s, nullstr, 0);
 	if ((vp->flags & VEXPORT) && localevar(vp->text)) {
@@ -869,7 +877,6 @@ unsetvar(const char *s)
 		*vpp = vp->next;
 		ckfree(vp);
 	}
-	INTON;
 	return (0);
 }