From 8af42882a51c632a14d77277df0740f1aa8c958a Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 4 Nov 2011 11:10:01 +0100 Subject: [PATCH] readline: Fix buffer overrun on re-add to history readline_hist_add() moves the history entry to the end of history. It uses memmove() to move rs->history[idx + 1..] to rs->history[idx..]. However, its size argument is off by two array elements, so it writes one element beyond rs->history[], and reads two. On my system, this clobbers rs->hist_entry and the hole right after it. Since the function assigns to rs->hist_entry in time, the bug has no ill effects for me. Spotted by Coverity. Signed-off-by: Markus Armbruster Signed-off-by: Stefan Hajnoczi --- readline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/readline.c b/readline.c index 6a3160aba..a6c0039ad 100644 --- a/readline.c +++ b/readline.c @@ -236,7 +236,7 @@ static void readline_hist_add(ReadLineState *rs, const char *cmdline) new_entry = hist_entry; /* Put this entry at the end of history */ memmove(&rs->history[idx], &rs->history[idx + 1], - (READLINE_MAX_CMDS - idx + 1) * sizeof(char *)); + (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *)); rs->history[READLINE_MAX_CMDS - 1] = NULL; for (; idx < READLINE_MAX_CMDS; idx++) { if (rs->history[idx] == NULL)