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-rw-r--r--ChangeLog3
-rw-r--r--Src/hist.c18
2 files changed, 19 insertions, 2 deletions
diff --git a/ChangeLog b/ChangeLog
index 22e4b9478..e40242eb8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
2015-10-21 Barton E. Schaefer <schaefer@zsh.org>
+ * 36909: Src/hist.c: in getargs(), sanity-check the offsets for
+ start and end of the requested words, in case of overflow
+
* 36871: Functions/Zle/bracketed-paste-magic: move initial call
to "zle .bracketed-paste-magic" to occur earlier in the function
diff --git a/Src/hist.c b/Src/hist.c
index 9c42d85c9..007366a49 100644
--- a/Src/hist.c
+++ b/Src/hist.c
@@ -2254,7 +2254,7 @@ static char *
getargs(Histent elist, int arg1, int arg2)
{
short *words = elist->words;
- int pos1, nwords = elist->nwords;
+ int pos1, pos2, nwords = elist->nwords;
if (arg2 < arg1 || arg1 >= nwords || arg2 >= nwords) {
/* remember, argN is indexed from 0, nwords is total no. of words */
@@ -2263,8 +2263,22 @@ getargs(Histent elist, int arg1, int arg2)
return NULL;
}
+ /* optimization for accessing entire history event */
+ if (arg1 == 0 && arg2 == nwords - 1)
+ return dupstring(elist->node.nam);
+
pos1 = words[2*arg1];
- return dupstrpfx(elist->node.nam + pos1, words[2*arg2+1] - pos1);
+ pos2 = words[2*arg2+1];
+
+ /* a word has to be at least one character long, so if the position
+ * of a word is less than its index, we've overflowed our signed
+ * short integer word range and the recorded position is garbage. */
+ if (pos1 < 0 || pos1 < arg1 || pos2 < 0 || pos2 < arg2) {
+ herrflush();
+ zerr("history event too long, can't index requested words");
+ return NULL;
+ }
+ return dupstrpfx(elist->node.nam + pos1, pos2 - pos1);
}
/**/