[PATCH] mtd: physmap: physmap-bt1-rom: Fix unintentional stack access

From: Gustavo A. R. Silva
Date: Fri Feb 12 2021 - 05:43:36 EST


Cast &data to (char *) in order to avoid unintentionally accessing
the stack.

Notice that data is of type u32, so any increment to &data
will be in the order of 4-byte chunks, and this piece of code
is actually intended to be a byte offset.

Fixes: b3e79e7682e0 ("mtd: physmap: Add Baikal-T1 physically mapped ROM support")
Addresses-Coverity-ID: 1497765 ("Out-of-bounds access")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
---
drivers/mtd/maps/physmap-bt1-rom.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/maps/physmap-bt1-rom.c b/drivers/mtd/maps/physmap-bt1-rom.c
index a35450002284..58782cfaf71c 100644
--- a/drivers/mtd/maps/physmap-bt1-rom.c
+++ b/drivers/mtd/maps/physmap-bt1-rom.c
@@ -79,7 +79,7 @@ static void __xipram bt1_rom_map_copy_from(struct map_info *map,
if (shift) {
chunk = min_t(ssize_t, 4 - shift, len);
data = readl_relaxed(src - shift);
- memcpy(to, &data + shift, chunk);
+ memcpy(to, (char *)&data + shift, chunk);
src += chunk;
to += chunk;
len -= chunk;
--
2.27.0