moonjuice/kernel_arpi
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

drm/amd/display: Avoid HDCP over-read and corruption

Browse Source 
[ Upstream commit 06888d571b ]

Instead of reading the desired 5 bytes of the actual target field,
the code was reading 8. This could result in a corrupted value if the
trailing 3 bytes were non-zero, so instead use an appropriately sized
and zero-initialized bounce buffer, and read only 5 bytes before casting
to u64.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kees Cook
2021-05-28 10:53:54 -07:00
committed by Greg Kroah-Hartman
parent 3c172f6e44
commit c5b518f4b9
1 changed files with 3 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c
View File

@@ -29,8 +29,10 @@ static inline enum mod_hdcp_status validate_bksv(struct mod_hdcp *hdcp)
{
uint64_t n = 0;
uint8_t count = 0;
u8 bksv[sizeof(n)] = { };
memcpy(&n, hdcp->auth.msg.hdcp1.bksv, sizeof(uint64_t));
memcpy(bksv, hdcp->auth.msg.hdcp1.bksv, sizeof(hdcp->auth.msg.hdcp1.bksv));
n = *(uint64_t *)bksv;
while (n) {
count++;