From adfbae9ffe339eed08d54a4eb87c93f4b35f214b Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Thu, 13 Apr 2023 13:03:49 -0700 Subject: [PATCH] drm/i915/gt: Avoid out-of-bounds access when loading HuC When HuC is loaded by GSC, there is no header definition for the kernel to look at and firmware is just handed to GSC. However when reading the version, it should still check the size of the blob to guarantee it's not incurring into out-of-bounds array access. If firmware is smaller than expected, the following message is now printed: # echo boom > /lib/firmware/i915/dg2_huc_gsc.bin # dmesg | grep -i huc [drm] GT0: HuC firmware i915/dg2_huc_gsc.bin: invalid size: 5 < 184 [drm] *ERROR* GT0: HuC firmware i915/dg2_huc_gsc.bin: fetch failed -ENODATA ... Even without this change the size, header and signature are still checked by GSC when loading, so this only avoids the out-of-bounds array access. Fixes: a7b516bd981f ("drm/i915/huc: Add fetch support for gsc-loaded HuC binary") Cc: Daniele Ceraolo Spurio Cc: Alan Previn Signed-off-by: Lucas De Marchi Reviewed-by: Daniele Ceraolo Spurio Link: https://patchwork.freedesktop.org/patch/msgid/20230413200349.3492571-1-lucas.demarchi@intel.com --- drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c index 264c952f777bb..24765c30a0e1d 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c @@ -488,12 +488,25 @@ static void __force_fw_fetch_failures(struct intel_uc_fw *uc_fw, int e) } } -static int check_gsc_manifest(const struct firmware *fw, +static int check_gsc_manifest(struct intel_gt *gt, + const struct firmware *fw, struct intel_uc_fw *uc_fw) { u32 *dw = (u32 *)fw->data; - u32 version_hi = dw[HUC_GSC_VERSION_HI_DW]; - u32 version_lo = dw[HUC_GSC_VERSION_LO_DW]; + u32 version_hi, version_lo; + size_t min_size; + + /* Check the size of the blob before examining buffer contents */ + min_size = sizeof(u32) * (HUC_GSC_VERSION_LO_DW + 1); + if (unlikely(fw->size < min_size)) { + gt_warn(gt, "%s firmware %s: invalid size: %zu < %zu\n", + intel_uc_fw_type_repr(uc_fw->type), uc_fw->file_selected.path, + fw->size, min_size); + return -ENODATA; + } + + version_hi = dw[HUC_GSC_VERSION_HI_DW]; + version_lo = dw[HUC_GSC_VERSION_LO_DW]; uc_fw->file_selected.ver.major = FIELD_GET(HUC_GSC_MAJOR_VER_HI_MASK, version_hi); uc_fw->file_selected.ver.minor = FIELD_GET(HUC_GSC_MINOR_VER_HI_MASK, version_hi); @@ -664,7 +677,7 @@ static int check_fw_header(struct intel_gt *gt, return 0; if (uc_fw->loaded_via_gsc) - err = check_gsc_manifest(fw, uc_fw); + err = check_gsc_manifest(gt, fw, uc_fw); else err = check_ccs_header(gt, fw, uc_fw); if (err) -- 2.30.2