From 06a040a31bcfc2673ab0670ee95fb9b078c4fdda Mon Sep 17 00:00:00 2001 From: Ladislav Michl Date: Tue, 12 Jul 2016 20:28:23 +0200 Subject: cmd: mtdparts: fix null pointer dereference in parse_mtdparts In case there is no mtdparts variable in relocated environment, NULL is assigned to p, which is later fed to strncpy. Also function parameter mtdparts is completely ignored, so use it in case mtdparts variable is not found in environment. This parameter is checked not to be NULL in caller. Signed-off-by: Ladislav Michl --- cmd/mtdparts.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/cmd/mtdparts.c b/cmd/mtdparts.c index 3a88a10ba3..995cb87b73 100644 --- a/cmd/mtdparts.c +++ b/cmd/mtdparts.c @@ -1524,7 +1524,7 @@ static int spread_partitions(void) */ static int parse_mtdparts(const char *const mtdparts) { - const char *p = mtdparts; + const char *p; struct mtd_device *dev; int err = 1; char tmp_parts[MTDPARTS_MAXLEN]; @@ -1538,20 +1538,25 @@ static int parse_mtdparts(const char *const mtdparts) } /* re-read 'mtdparts' variable, mtd_devices_init may be updating env */ - if (gd->flags & GD_FLG_ENV_READY) { + if (gd->flags & GD_FLG_ENV_READY) p = getenv("mtdparts"); - } else { - p = tmp_parts; - getenv_f("mtdparts", tmp_parts, MTDPARTS_MAXLEN); + else { + if (getenv_f("mtdparts", tmp_parts, MTDPARTS_MAXLEN) != -1) + p = tmp_parts; + else + p = NULL; } + if (!p) + p = mtdparts; + if (strncmp(p, "mtdparts=", 9) != 0) { printf("mtdparts variable doesn't start with 'mtdparts='\n"); return err; } p += 9; - while (p && (*p != '\0')) { + while (*p != '\0') { err = 1; if ((device_parse(p, &p, &dev) != 0) || (!dev)) break; @@ -1569,12 +1574,10 @@ static int parse_mtdparts(const char *const mtdparts) list_add_tail(&dev->link, &devices); err = 0; } - if (err == 1) { + if (err == 1) device_delall(&devices); - return 1; - } - return 0; + return err; } /** -- cgit