firmware: Sigma: Prevent out of bounds memory access

The SigmaDSP firmware loader currently does not perform enough boundary size
checks when processing the firmware. As a result it is possible that a
malformed firmware can cause an out of bounds memory access.

This patch adds checks which ensure that both the action header and the payload
are completely inside the firmware data boundaries before processing them.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org

1 files changed, 0 insertions, 5 deletions

diff --git a/include/linux/sigma.h b/include/linux/sigma.h
index e2accb3164d8..9a138c2946bb 100644
--- a/include/linux/sigma.h
+++ b/include/linux/sigma.h
@@ -50,11 +50,6 @@ static inline u32 sigma_action_len(struct sigma_action *sa)
         return (sa->len_hi << 16) | sa->len;
 }
 
-static inline size_t sigma_action_size(struct sigma_action *sa, u32 payload_len)
-{
-        return sizeof(*sa) + payload_len + (payload_len % 2);
-}
-
 extern int process_sigma_firmware(struct i2c_client *client, const char *name);
 
 #endif