| Message ID | 20210707134739.1869481-1-sudeep.holla@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | firmware: arm_ffa: Fix a possible ffa_linux_errmap buffer overflow | expand |
On Wed, 7 Jul 2021 14:47:39 +0100, Sudeep Holla wrote: > The ffa_linux_errmap buffer access index is supposed to range from 0-8 > but it ranges from 1-9 instead. It reads one element out of bounds. It > also changes the success into -EINVAL though ffa_to_linux_errno 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. Applied to sudeep.holla/linux (for-next/ffa), thanks! [1/1] firmware: arm_ffa: Fix a possible ffa_linux_errmap buffer overflow https://git.kernel.org/sudeep.holla/c/dd925db6f0 -- Regards, Sudeep
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index 88b822575ac4..c9fb56afbcb4 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -149,8 +149,10 @@ static const int ffa_linux_errmap[] = { static inline int ffa_to_linux_errno(int errno) { - if (errno < FFA_RET_SUCCESS && errno >= -ARRAY_SIZE(ffa_linux_errmap)) - return ffa_linux_errmap[-errno]; + int err_idx = -errno; + + if (err_idx >= 0 && err_idx < ARRAY_SIZE(ffa_linux_errmap)) + return ffa_linux_errmap[err_idx]; return -EINVAL; }
The ffa_linux_errmap buffer access index is supposed to range from 0-8 but it ranges from 1-9 instead. It reads one element out of bounds. It also changes the success into -EINVAL though ffa_to_linux_errno 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. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- drivers/firmware/arm_ffa/driver.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)