From d1b03ef8ddc9ec84e52e6155fd510e601f043b20 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Fri, 15 May 2020 12:18:02 -0700 Subject: [PATCH] s3: lib: Paranoia around use of snprintf copying into a fixed-size buffer from a getenv() pointer. Post checks for overflow/error. Signed-off-by: Jeremy Allison Reviewed-by: Andrew Bartlett Autobuild-User(master): Jeremy Allison Autobuild-Date(master): Mon May 18 23:42:57 UTC 2020 on sn-devel-184 (cherry picked from commit dd1f750293ef4361455a5d5b63fc7a89495715b7) --- lib/util/util_paths.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/lib/util/util_paths.c b/lib/util/util_paths.c index c05246a7407..c0ee5c32c30 100644 --- a/lib/util/util_paths.c +++ b/lib/util/util_paths.c @@ -73,12 +73,16 @@ static char *get_user_home_dir(TALLOC_CTX *mem_ctx) rc = getpwuid_r(getuid(), &pwd, buf, NSS_BUFLEN_PASSWD, &pwdbuf); if (rc != 0 || pwdbuf == NULL ) { + int len_written; const char *szPath = getenv("HOME"); if (szPath == NULL) { return NULL; } - snprintf(buf, sizeof(buf), "%s", szPath); - + len_written = snprintf(buf, sizeof(buf), "%s", szPath); + if (len_written >= sizeof(buf) || len_written < 0) { + /* Output was truncated or an error. */ + return NULL; + } return talloc_strdup(mem_ctx, buf); } -- 2.47.2