From 2673cefa99ca918e7ac5b0388ff578a83656c896 Mon Sep 17 00:00:00 2001 From: Nikita Zhandarovich Date: Fri, 29 May 2026 17:57:58 +0300 Subject: [PATCH 1/2] drm/i915/edp: Check supported link rates DPCD read intel_edp_set_sink_rates() reads DP_SUPPORTED_LINK_RATES into a local stack array and then parses the array unconditionally. If the read fails, the array contents are not valid and may result in bogus sink link rates being used. Use drm_dp_dpcd_read_data() and clear the sink rate array on failure, so the existing parser falls back to the default sink rate handling. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. Fixes: 68f357cb7347 ("drm/i915/dp: generate and cache sink rate array for all DP, not just eDP 1.4") Signed-off-by: Nikita Zhandarovich Reviewed-by: Jani Nikula Link: https://patch.msgid.link/20260529145759.1640646-1-n.zhandarovich@fintech.ru Signed-off-by: Jani Nikula (cherry picked from commit bd61c7756b34157e093028225a69383b4b1203cc) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/display/intel_dp.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 6ef2a0043cda..5c3e816b0135 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4678,10 +4678,17 @@ intel_edp_set_sink_rates(struct intel_dp *intel_dp) if (intel_dp->edp_dpcd[0] >= DP_EDP_14) { __le16 sink_rates[DP_MAX_SUPPORTED_RATES]; + int ret; int i; - drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES, - sink_rates, sizeof(sink_rates)); + ret = drm_dp_dpcd_read_data(&intel_dp->aux, + DP_SUPPORTED_LINK_RATES, + sink_rates, sizeof(sink_rates)); + if (ret < 0) { + drm_dbg_kms(display->drm, + "Unable to read eDP supported link rates, using default rates\n"); + memset(sink_rates, 0, sizeof(sink_rates)); + } for (i = 0; i < ARRAY_SIZE(sink_rates); i++) { int rate; From d21ad938398bca695a511307de38a65889e3b354 Mon Sep 17 00:00:00 2001 From: Joonas Lahtinen Date: Wed, 10 Jun 2026 09:03:14 +0300 Subject: [PATCH 2/2] drm/i915/gem: Fix phys BO pread/pwrite with offset sg_page() returns struct page pointer not (void *) so the scaling of pread/pwrite is wrong for phys BO and wrong parts of BO would be accessed if non-zero offset is used. Last impacted platform with overlay or cursor planes using phys mapping was Gen3/945G/Lakeport. Reported-by: Matthew Wilcox (Oracle) Fixes: c6790dc22312 ("drm/i915: Wean off drm_pci_alloc/drm_pci_free") Cc: # v4.5+ Cc: Tvrtko Ursulin Cc: Simona Vetter Cc: Jani Nikula Cc: Rodrigo Vivi Signed-off-by: Joonas Lahtinen Reviewed-by: Tvrtko Ursulin Link: https://patch.msgid.link/20260610060314.26111-1-joonas.lahtinen@linux.intel.com (cherry picked from commit 3e49a2f85070b2fb672c1e0fdba281a4ea3aebe6) Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/gem/i915_gem_phys.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/i915_gem_phys.c index e375afbf458e..d53129eb5603 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_phys.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_phys.c @@ -18,6 +18,17 @@ #include "i915_gem_tiling.h" #include "i915_scatterlist.h" +/* Abuse scatterlist to store pointer instead of struct page. */ +static inline void __set_phys_vaddr(struct scatterlist *sg, void *vaddr) +{ + sg_assign_page(sg, (struct page *)vaddr); +} + +static inline void *__get_phys_vaddr(struct scatterlist *sg) +{ + return (void *)sg_page(sg); +} + static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj) { struct address_space *mapping = obj->base.filp->f_mapping; @@ -58,7 +69,7 @@ static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj) sg->offset = 0; sg->length = obj->base.size; - sg_assign_page(sg, (struct page *)vaddr); + __set_phys_vaddr(sg, vaddr); sg_dma_address(sg) = dma; sg_dma_len(sg) = obj->base.size; @@ -99,7 +110,7 @@ i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, struct sg_table *pages) { dma_addr_t dma = sg_dma_address(pages->sgl); - void *vaddr = sg_page(pages->sgl); + void *vaddr = __get_phys_vaddr(pages->sgl); __i915_gem_object_release_shmem(obj, pages, false); @@ -139,7 +150,7 @@ i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj, int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj, const struct drm_i915_gem_pwrite *args) { - void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset; + void *vaddr = __get_phys_vaddr(obj->mm.pages->sgl) + args->offset; char __user *user_data = u64_to_user_ptr(args->data_ptr); struct drm_i915_private *i915 = to_i915(obj->base.dev); int err; @@ -170,7 +181,7 @@ int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj, int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj, const struct drm_i915_gem_pread *args) { - void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset; + void *vaddr = __get_phys_vaddr(obj->mm.pages->sgl) + args->offset; char __user *user_data = u64_to_user_ptr(args->data_ptr); int err;