From: Alex Hung alex.hung@amd.com

stable inclusion from stable-v6.6.55 commit be2ca7a2c1561390d28bf2f92654d819659ba510 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYPKL CVE: CVE-2024-47704

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

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[ Upstream commit 0beca868cde8742240cd0038141c30482d2b7eb8 ]

[WHAT & HOW] Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing.

This fixes 2 FORWARD_NULL issues reported by Coverity.

Reviewed-by: Rodrigo Siqueira rodrigo.siqueira@amd.com Signed-off-by: Jerry Zuo jerry.zuo@amd.com Signed-off-by: Alex Hung alex.hung@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Jinjiang Tu tujinjiang@huawei.com --- .../gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_dp.c | 7 +++++++ 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_dp.c b/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_dp.c index e1257404357b..d0148f10dfc0 100644 --- a/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_dp.c +++ b/drivers/gpu/drm/amd/display/dc/link/hwss/link_hwss_hpo_dp.c @@ -28,6 +28,8 @@ #include "dccg.h" #include "clk_mgr.h"

+#define DC_LOGGER link->ctx->logger + void set_hpo_dp_throttled_vcp_size(struct pipe_ctx *pipe_ctx, struct fixed31_32 throttled_vcp_size) { @@ -124,6 +126,11 @@ void disable_hpo_dp_link_output(struct dc_link *link, const struct link_resource *link_res, enum signal_type signal) { + if (!link_res->hpo_dp_link_enc) { + DC_LOG_ERROR("%s: invalid hpo_dp_link_enc\n", __func__); + return; + } + link_res->hpo_dp_link_enc->funcs->link_disable(link_res->hpo_dp_link_enc); link_res->hpo_dp_link_enc->funcs->disable_link_phy( link_res->hpo_dp_link_enc, signal);