4.19-stable review patch. If anyone has any objections, please let me know.
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From: Paulo Miguel Almeida paulo.miguel.almeida.rodenas@gmail.com
[ Upstream commit c81c5bd5cf2f428867e0bcfcccd4e4d2f8c68f51 ]
One-element arrays are deprecated, and we are replacing them with flexible array members instead. So, replace one-element array with flexible-array member in struct _ATOM_FAKE_EDID_PATCH_RECORD and refactor the rest of the code accordingly.
It's worth mentioning that doing a build before/after this patch results in no binary output differences.
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/239 Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836 [1]
Reviewed-by: Kees Cook keescook@chromium.org Signed-off-by: Paulo Miguel Almeida paulo.miguel.almeida.rodenas@gmail.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Stable-dep-of: 17c6baff3d5f ("drm/radeon: properly handle vbios fake edid sizing") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/radeon/atombios.h | 2 +- drivers/gpu/drm/radeon/radeon_atombios.c | 7 +++++-- 2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios.h b/drivers/gpu/drm/radeon/atombios.h index 4b86e8b450090..e3f4964647641 100644 --- a/drivers/gpu/drm/radeon/atombios.h +++ b/drivers/gpu/drm/radeon/atombios.h @@ -3615,7 +3615,7 @@ typedef struct _ATOM_FAKE_EDID_PATCH_RECORD { UCHAR ucRecordType; UCHAR ucFakeEDIDLength; - UCHAR ucFakeEDIDString[1]; // This actually has ucFakeEdidLength elements. + UCHAR ucFakeEDIDString[]; // This actually has ucFakeEdidLength elements. } ATOM_FAKE_EDID_PATCH_RECORD;
typedef struct _ATOM_PANEL_RESOLUTION_PATCH_RECORD diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c index 821b03d6142b0..0d11d6d1f5f0a 100644 --- a/drivers/gpu/drm/radeon/radeon_atombios.c +++ b/drivers/gpu/drm/radeon/radeon_atombios.c @@ -1742,8 +1742,11 @@ struct radeon_encoder_atom_dig *radeon_atombios_get_lvds_info(struct } } record += fake_edid_record->ucFakeEDIDLength ? - fake_edid_record->ucFakeEDIDLength + 2 : - sizeof(ATOM_FAKE_EDID_PATCH_RECORD); + struct_size(fake_edid_record, + ucFakeEDIDString, + fake_edid_record->ucFakeEDIDLength) : + /* empty fake edid record must be 3 bytes long */ + sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1; break; case LCD_PANEL_RESOLUTION_RECORD_TYPE: panel_res_record = (ATOM_PANEL_RESOLUTION_PATCH_RECORD *)record;