From b47e69e69e7d68b18fe0f0064b1eabe2dc73465e Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Mon, 15 May 2017 17:57:09 +0000 Subject: [PATCH] getusershell: don't write past end of line buffer reading local shells _local_initshells did not reset cp to the beginning of the line buffer for every iteration that it called fgets(3), leading to writing past the end of line with fairly long /etc/shells or excessively long line lengths. Correct this by properly resetting cp. PR: 192528 Submitted by: Kyle Evans Reviewed by: cem, jilles Differential Revision: https://reviews.freebsd.org/D10690 --- lib/libc/gen/getusershell.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/libc/gen/getusershell.c b/lib/libc/gen/getusershell.c index 56659709ba1..810a19af837 100644 --- a/lib/libc/gen/getusershell.c +++ b/lib/libc/gen/getusershell.c @@ -115,8 +115,8 @@ _local_initshells(void *rv, void *cb_data, va_list ap) if ((fp = fopen(_PATH_SHELLS, "re")) == NULL) return NS_UNAVAIL; - cp = line; - while (fgets(cp, MAXPATHLEN + 1, fp) != NULL) { + while (fgets(line, MAXPATHLEN + 1, fp) != NULL) { + cp = line; while (*cp != '#' && *cp != '/' && *cp != '\0') cp++; if (*cp == '#' || *cp == '\0') @@ -124,7 +124,7 @@ _local_initshells(void *rv, void *cb_data, va_list ap) sp = cp; while (!isspace(*cp) && *cp != '#' && *cp != '\0') cp++; - *cp++ = '\0'; + *cp = '\0'; sl_add(sl, strdup(sp)); } (void)fclose(fp);