From: Alex Hung alex.hung@amd.com

stable inclusion from stable-v5.10.222 commit b5b8837d066cc182ff69fb5629ad32ade5484567 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGSSE CVE: CVE-2024-42121

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 59d99deb330af206a4541db0c4da8f73880fba03 ]

[WHAT] msg_id is used as an array index and it cannot be a negative value, and therefore cannot be equal to MOD_HDCP_MESSAGE_ID_INVALID (-1).

[HOW] Check whether msg_id is valid before reading and setting.

This fixes 4 OVERRUN issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira rodrigo.siqueira@amd.com Acked-by: Wayne Lin wayne.lin@amd.com Signed-off-by: Alex Hung alex.hung@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Li Nan linan122@huawei.com --- drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c | 8 ++++++++ 1 file changed, 8 insertions(+)

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 f7b5583ee609..8e9caae7c955 100644 --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c @@ -156,6 +156,10 @@ static enum mod_hdcp_status read(struct mod_hdcp *hdcp, uint32_t cur_size = 0; uint32_t data_offset = 0;

+ if (msg_id == MOD_HDCP_MESSAGE_ID_INVALID) { + return MOD_HDCP_STATUS_DDC_FAILURE; + } + if (is_dp_hdcp(hdcp)) { while (buf_len > 0) { cur_size = MIN(buf_len, HDCP_MAX_AUX_TRANSACTION_SIZE); @@ -215,6 +219,10 @@ static enum mod_hdcp_status write(struct mod_hdcp *hdcp, uint32_t cur_size = 0; uint32_t data_offset = 0;

+ if (msg_id == MOD_HDCP_MESSAGE_ID_INVALID) { + return MOD_HDCP_STATUS_DDC_FAILURE; + } + if (is_dp_hdcp(hdcp)) { while (buf_len > 0) { cur_size = MIN(buf_len, HDCP_MAX_AUX_TRANSACTION_SIZE);