From 689d9bfcf6859e5ce85c296ff0f23b5c08b1fedc Mon Sep 17 00:00:00 2001 From: NRK Date: Mon, 31 Oct 2022 00:10:45 +0600 Subject: [PATCH] fix leak when getline fails according to the getline(3) documentation, the calling code needs to free the buffer even if getline fails. dmenu currently doesn't do that which results in a small leak in case of failure (e.g when piped /dev/null) $ ./dmenu < /dev/null ==8201==ERROR: LeakSanitizer: detected memory leaks Direct leak of 120 byte(s) in 1 object(s) allocated from: #0 0x7f6bf5785ef7 in malloc #1 0x7f6bf538ec84 in __getdelim #2 0x405d0c in readstdin dmenu.c:557 moving `line = NULL` inside the loop body wasn't strictly necessary, but IMO it makes it more apparent that `line` is getting cleared to NULL after each successful iteration. --- dmenu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/dmenu.c b/dmenu.c index e7be8af..e786d7a 100644 --- a/dmenu.c +++ b/dmenu.c @@ -554,7 +554,7 @@ readstdin(void) ssize_t len; /* read each line from stdin and add it to the item list */ - for (i = 0; (len = getline(&line, &junk, stdin)) != -1; i++, line = NULL) { + for (i = 0; (len = getline(&line, &junk, stdin)) != -1; i++) { if (i + 1 >= size / sizeof *items) if (!(items = realloc(items, (size += BUFSIZ)))) die("cannot realloc %zu bytes:", size); @@ -562,7 +562,9 @@ readstdin(void) line[len - 1] = '\0'; items[i].text = line; items[i].out = 0; + line = NULL; } + free(line); if (items) items[i].text = NULL; lines = MIN(lines, i);