From: Kees Cook keescook@chromium.org
[ Upstream commit 4076ea2419cf15bc1e1580f8b24ddf675fbdb02c ]
Both Coverity and GCC with -Wstringop-overflow noticed that nvif_outp_acquire_dp() accidentally defined its second argument with 1 additional element:
drivers/gpu/drm/nouveau/dispnv50/disp.c: In function 'nv50_pior_atomic_enable': drivers/gpu/drm/nouveau/dispnv50/disp.c:1813:17: error: 'nvif_outp_acquire_dp' accessing 16 bytes in a region of size 15 [-Werror=stringop-overflow=] 1813 | nvif_outp_acquire_dp(&nv_encoder->outp, nv_encoder->dp.dpcd, 0, 0, false, false); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/nouveau/dispnv50/disp.c:1813:17: note: referencing argument 2 of type 'u8[16]' {aka 'unsigned char[16]'} drivers/gpu/drm/nouveau/include/nvif/outp.h:24:5: note: in a call to function 'nvif_outp_acquire_dp' 24 | int nvif_outp_acquire_dp(struct nvif_outp *, u8 dpcd[16], | ^~~~~~~~~~~~~~~~~~~~
Avoid these warnings by defining the argument size using the matching define (DP_RECEIVER_CAP_SIZE, 15) instead of having it be a literal (and incorrect) value (16).
Reported-by: coverity-bot keescook+coverity-bot@chromium.org Addresses-Coverity-ID: 1527269 ("Memory - corruptions") Addresses-Coverity-ID: 1527268 ("Memory - corruptions") Link: https://lore.kernel.org/lkml/202211100848.FFBA2432@keescook/ Link: https://lore.kernel.org/lkml/202211100848.F4C2819BB@keescook/ Fixes: 813443721331 ("drm/nouveau/disp: move DP link config into acquire") Reviewed-by: Lyude Paul lyude@redhat.com Cc: Ben Skeggs bskeggs@redhat.com Cc: Karol Herbst kherbst@redhat.com Cc: David Airlie airlied@gmail.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Dave Airlie airlied@redhat.com Cc: "Gustavo A. R. Silva" gustavo@embeddedor.com Cc: dri-devel@lists.freedesktop.org Cc: nouveau@lists.freedesktop.org Signed-off-by: Kees Cook keescook@chromium.org Link: https://lore.kernel.org/r/20221127183036.never.139-kees@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/nouveau/include/nvif/outp.h | 3 ++- drivers/gpu/drm/nouveau/nvif/outp.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/include/nvif/outp.h b/drivers/gpu/drm/nouveau/include/nvif/outp.h index 45daadec3c0c7..fa76a7b5e4b37 100644 --- a/drivers/gpu/drm/nouveau/include/nvif/outp.h +++ b/drivers/gpu/drm/nouveau/include/nvif/outp.h @@ -3,6 +3,7 @@ #define __NVIF_OUTP_H__ #include <nvif/object.h> #include <nvif/if0012.h> +#include <drm/display/drm_dp.h> struct nvif_disp;
struct nvif_outp { @@ -21,7 +22,7 @@ int nvif_outp_acquire_rgb_crt(struct nvif_outp *); int nvif_outp_acquire_tmds(struct nvif_outp *, int head, bool hdmi, u8 max_ac_packet, u8 rekey, u8 scdc, bool hda); int nvif_outp_acquire_lvds(struct nvif_outp *, bool dual, bool bpc8); -int nvif_outp_acquire_dp(struct nvif_outp *, u8 dpcd[16], +int nvif_outp_acquire_dp(struct nvif_outp *outp, u8 dpcd[DP_RECEIVER_CAP_SIZE], int link_nr, int link_bw, bool hda, bool mst); void nvif_outp_release(struct nvif_outp *); int nvif_outp_infoframe(struct nvif_outp *, u8 type, struct nvif_outp_infoframe_v0 *, u32 size); diff --git a/drivers/gpu/drm/nouveau/nvif/outp.c b/drivers/gpu/drm/nouveau/nvif/outp.c index 7da39f1eae9fb..c24bc5eae3ecf 100644 --- a/drivers/gpu/drm/nouveau/nvif/outp.c +++ b/drivers/gpu/drm/nouveau/nvif/outp.c @@ -127,7 +127,7 @@ nvif_outp_acquire(struct nvif_outp *outp, u8 proto, struct nvif_outp_acquire_v0 }
int -nvif_outp_acquire_dp(struct nvif_outp *outp, u8 dpcd[16], +nvif_outp_acquire_dp(struct nvif_outp *outp, u8 dpcd[DP_RECEIVER_CAP_SIZE], int link_nr, int link_bw, bool hda, bool mst) { struct nvif_outp_acquire_v0 args;