From: Sudeep Holla <sudeep.holla@xxxxxxx> [ Upstream commit 7a691f16ccad05d770f813d9c4b4337a30c6d63f ] The scmi_linux_errmap buffer access index is supposed to depend on the array size to prevent element out of bounds access. It uses SCMI_ERR_MAX to check bounds but that can mismatch with the array size. It also changes the success into -EIO though scmi_linux_errmap is never used in case of success, it is expected to work for success case too. It is slightly confusing code as the negative of the error code is used as index to the buffer. Fix it by negating it at the start and make it more readable. Link: https://lore.kernel.org/r/20210707135028.1869642-1-sudeep.holla@xxxxxxx Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Reviewed-by: Cristian Marussi <cristian.marussi@xxxxxxx> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/firmware/arm_scmi/driver.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index af4560dab6b4..6fa024d1dd99 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -43,7 +43,6 @@ enum scmi_error_codes { SCMI_ERR_GENERIC = -8, /* Generic Error */ SCMI_ERR_HARDWARE = -9, /* Hardware Error */ SCMI_ERR_PROTOCOL = -10,/* Protocol Error */ - SCMI_ERR_MAX }; /* List of all SCMI devices active in system */ @@ -118,8 +117,10 @@ static const int scmi_linux_errmap[] = { static inline int scmi_to_linux_errno(int errno) { - if (errno < SCMI_SUCCESS && errno > SCMI_ERR_MAX) - return scmi_linux_errmap[-errno]; + int err_idx = -errno; + + if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap)) + return scmi_linux_errmap[err_idx]; return -EIO; } -- 2.30.2
