diff options
| author | Kees Cook <keescook@chromium.org> | 2021-05-28 20:53:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-19 11:00:52 +0300 |
| commit | 44c7c901cb368a9f2493748f213b247b5872639f (patch) | |
| tree | 3db341880ffc47bc0520c54d61fab0e9c323b35d /drivers/gpu | |
| parent | 56f0b2c209daff9ac764a02255502e207feb5ba5 (diff) | |
| download | linux-44c7c901cb368a9f2493748f213b247b5872639f.tar.xz | |
drm/amd/display: Avoid HDCP over-read and corruption
[ Upstream commit 06888d571b513cbfc0b41949948def6cb81021b2 ]
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>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c index 73ca49f05bd3..eb56526ec32c 100644 --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c @@ -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++; |