From: Harry Wentland <harry.wentland@amd.com> mainline inclusion from mainline-v7.1-rc7 commit f0f3981c43b32cadfe373d636d9e9ca522bb3702 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15831 CVE: CVE-2026-53137 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- [Why & How] During HDCP 2.x repeater authentication over HDMI, the driver reads the sink's RxStatus register and extracts a 10-bit message size field (max value 1023). This value is used as the read length for the ReceiverID list without being clamped to the size of the destination buffer rx_id_list[177]. A malicious HDMI repeater could advertise a message size larger than the buffer, causing an out-of-bounds write during the I2C read. Clamp the read length in mod_hdcp_read_rx_id_list() to the size of the rx_id_list buffer, matching the approach already used in the DP branch. Fixes: eff682f83c9c ("drm/amd/display: Add DDC handles for HDCP2.2") Assisted-by: Copilot:claude-opus-4.6 Reviewed-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Ray Wu <ray.wu@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 229212219e4247d9486f8ba41ef087358490be09) Cc: stable@vger.kernel.org Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c index 1b2df97226a3..26956be604c3 100644 --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c @@ -531,7 +531,8 @@ enum mod_hdcp_status mod_hdcp_read_rx_id_list(struct mod_hdcp *hdcp) } else { status = read(hdcp, MOD_HDCP_MESSAGE_ID_READ_REPEATER_AUTH_SEND_RECEIVERID_LIST, hdcp->auth.msg.hdcp2.rx_id_list, - hdcp->auth.msg.hdcp2.rx_id_list_size); + MIN(hdcp->auth.msg.hdcp2.rx_id_list_size, + sizeof(hdcp->auth.msg.hdcp2.rx_id_list))); } return status; } -- 2.34.1