diff options
| author | Markus Armbruster <armbru@redhat.com> | 2011-11-04 11:10:01 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> | 2011-11-07 08:03:49 +0000 |
| commit | 8af42882a51c632a14d77277df0740f1aa8c958a (patch) | |
| tree | 5dd88832b4fabe453fc84169da51f730b22a7718 | |
| parent | 47e8dd8fe9d83e8b51d40c2b87d7983bd0a78206 (diff) | |
| download | qemu-8af42882a51c632a14d77277df0740f1aa8c958a.tar.gz qemu-8af42882a51c632a14d77277df0740f1aa8c958a.tar.bz2 qemu-8af42882a51c632a14d77277df0740f1aa8c958a.zip | |
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 <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
| -rw-r--r-- | readline.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/readline.c b/readline.c index 6a3160aba5..a6c0039ad2 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) |