[PATCH 5.15 153/691] mtd: slram: insert break after errors in parsing the map

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mirsad Todorovac <mtodorovac69@xxxxxxxxx>

[ Upstream commit 336c218dd7f0588ed8a7345f367975a00a4f003f ]

GCC 12.3.0 compiler on linux-next next-20240709 tree found the execution
path in which, due to lazy evaluation, devlength isn't initialised with the
parsed string:

   289		while (map) {
   290			devname = devstart = devlength = NULL;
   291
   292			if (!(devname = strsep(&map, ","))) {
   293				E("slram: No devicename specified.\n");
   294				break;
   295			}
   296			T("slram: devname = %s\n", devname);
   297			if ((!map) || (!(devstart = strsep(&map, ",")))) {
   298				E("slram: No devicestart specified.\n");
   299			}
   300			T("slram: devstart = %s\n", devstart);
 → 301			if ((!map) || (!(devlength = strsep(&map, ",")))) {
   302				E("slram: No devicelength / -end specified.\n");
   303			}
 → 304			T("slram: devlength = %s\n", devlength);
   305			if (parse_cmdline(devname, devstart, devlength) != 0) {
   306				return(-EINVAL);
   307			}

Parsing should be finished after map == NULL, so a break is best inserted after
each E("slram: ... \n") error message.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Vignesh Raghavendra <vigneshr@xxxxxx>
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Mirsad Todorovac <mtodorovac69@xxxxxxxxx>
Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Link: https://lore.kernel.org/linux-mtd/20240711234319.637824-1-mtodorovac69@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/mtd/devices/slram.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mtd/devices/slram.c b/drivers/mtd/devices/slram.c
index 28131a127d065..8297b366a0669 100644
--- a/drivers/mtd/devices/slram.c
+++ b/drivers/mtd/devices/slram.c
@@ -296,10 +296,12 @@ static int __init init_slram(void)
 		T("slram: devname = %s\n", devname);
 		if ((!map) || (!(devstart = strsep(&map, ",")))) {
 			E("slram: No devicestart specified.\n");
+			break;
 		}
 		T("slram: devstart = %s\n", devstart);
 		if ((!map) || (!(devlength = strsep(&map, ",")))) {
 			E("slram: No devicelength / -end specified.\n");
+			break;
 		}
 		T("slram: devlength = %s\n", devlength);
 		if (parse_cmdline(devname, devstart, devlength) != 0) {
-- 
2.43.0