avcodec/cbs_h2645: Avoid function pointer casts, fix UB

The SEI message read/write functions are called
via function pointers where the SEI message-specific
context is passed as void*. But the actual function
definitions use a pointer to their proper context
in place of void*, making the calls undefined behaviour.
Clang UBSan 17 warns about this.

This commit fixes this by adding wrapper functions
(created via macros) that have the right type that
call the actual functions. This reduced the number of failing
FATE tests with UBSan from 164 to 85 here.

Reviewed-by: Mark Thompson <sw@jkqxz.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

6 files changed, 88 insertions, 82 deletions

diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 2fb249bcd3..8e4af7b2cc 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -235,6 +235,16 @@ static int cbs_h265_payload_extension_present(GetBitContext *gbc, uint32_t paylo
 #define FUNC_H266(name) FUNC_NAME1(READWRITE, h266, name)
 #define FUNC_SEI(name)  FUNC_NAME1(READWRITE, sei,  name)
 
+#define SEI_FUNC(name, args) \
+static int FUNC(name) args;  \
+static int FUNC(name ## _internal)(CodedBitstreamContext *ctx, \
+                                   RWContext *rw, void *cur,   \
+                                   SEIMessageState *state)     \
+{ \
+    return FUNC(name)(ctx, rw, cur, state); \
+} \
+static int FUNC(name) args
+
 #define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL)
 
 #define u(width, name, range_min, range_max) \
@@ -2070,6 +2080,11 @@ const CodedBitstreamType ff_cbs_type_h266 = {
     .close             = &cbs_h266_close,
 };
 
+// Macro for the read/write pair.
+#define SEI_MESSAGE_RW(codec, name) \
+    .read  = cbs_ ## codec ## _read_  ## name ## _internal, \
+    .write = cbs_ ## codec ## _write_ ## name ## _internal
+
 static const SEIMessageTypeDescriptor cbs_sei_common_types[] = {
     {
         SEI_TYPE_FILLER_PAYLOAD,
diff --git a/libavcodec/cbs_h264_syntax_template.c b/libavcodec/cbs_h264_syntax_template.c
index 0f8bba4a0d..4d2d303722 100644
--- a/libavcodec/cbs_h264_syntax_template.c
+++ b/libavcodec/cbs_h264_syntax_template.c
@@ -510,9 +510,9 @@ static int FUNC(pps)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(sei_buffering_period)(CodedBitstreamContext *ctx, RWContext *rw,
-                                      H264RawSEIBufferingPeriod *current,
-                                      SEIMessageState *sei)
+SEI_FUNC(sei_buffering_period, (CodedBitstreamContext *ctx, RWContext *rw,
+                                H264RawSEIBufferingPeriod *current,
+                                SEIMessageState *sei))
 {
     CodedBitstreamH264Context *h264 = ctx->priv_data;
     const H264RawSPS *sps;
@@ -604,9 +604,8 @@ static int FUNC(sei_pic_timestamp)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(sei_pic_timing)(CodedBitstreamContext *ctx, RWContext *rw,
-                                H264RawSEIPicTiming *current,
-                                SEIMessageState *sei)
+SEI_FUNC(sei_pic_timing, (CodedBitstreamContext *ctx, RWContext *rw,
+                          H264RawSEIPicTiming *current, SEIMessageState *sei))
 {
     CodedBitstreamH264Context *h264 = ctx->priv_data;
     const H264RawSPS *sps;
@@ -676,9 +675,9 @@ static int FUNC(sei_pic_timing)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(sei_pan_scan_rect)(CodedBitstreamContext *ctx, RWContext *rw,
-                                   H264RawSEIPanScanRect *current,
-                                   SEIMessageState *sei)
+SEI_FUNC(sei_pan_scan_rect, (CodedBitstreamContext *ctx, RWContext *rw,
+                             H264RawSEIPanScanRect *current,
+                             SEIMessageState *sei))
 {
     int err, i;
 
@@ -703,9 +702,9 @@ static int FUNC(sei_pan_scan_rect)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(sei_recovery_point)(CodedBitstreamContext *ctx, RWContext *rw,
-                                    H264RawSEIRecoveryPoint *current,
-                                    SEIMessageState *sei)
+SEI_FUNC(sei_recovery_point, (CodedBitstreamContext *ctx, RWContext *rw,
+                              H264RawSEIRecoveryPoint *current,
+                              SEIMessageState *sei))
 {
     int err;
 
@@ -719,9 +718,9 @@ static int FUNC(sei_recovery_point)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(film_grain_characteristics)(CodedBitstreamContext *ctx, RWContext *rw,
-                                            H264RawFilmGrainCharacteristics *current,
-                                            SEIMessageState *state)
+SEI_FUNC(film_grain_characteristics, (CodedBitstreamContext *ctx, RWContext *rw,
+                                      H264RawFilmGrainCharacteristics *current,
+                                      SEIMessageState *state))
 {
     CodedBitstreamH264Context *h264 = ctx->priv_data;
     const H264RawSPS *sps;
@@ -802,9 +801,9 @@ static int FUNC(film_grain_characteristics)(CodedBitstreamContext *ctx, RWContex
     return 0;
 }
 
-static int FUNC(sei_display_orientation)(CodedBitstreamContext *ctx, RWContext *rw,
-                                         H264RawSEIDisplayOrientation *current,
-                                         SEIMessageState *sei)
+SEI_FUNC(sei_display_orientation, (CodedBitstreamContext *ctx, RWContext *rw,
+                                   H264RawSEIDisplayOrientation *current,
+                                   SEIMessageState *sei))
 {
     int err;
 
diff --git a/libavcodec/cbs_h265_syntax_template.c b/libavcodec/cbs_h265_syntax_template.c
index 2d4b954718..86ca00a0c9 100644
--- a/libavcodec/cbs_h265_syntax_template.c
+++ b/libavcodec/cbs_h265_syntax_template.c
@@ -1618,9 +1618,9 @@ static int FUNC(slice_segment_header)(CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(sei_buffering_period)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIBufferingPeriod *current, SEIMessageState *sei)
+SEI_FUNC(sei_buffering_period, (CodedBitstreamContext *ctx, RWContext *rw,
+                                H265RawSEIBufferingPeriod *current,
+                                SEIMessageState *sei))
 {
     CodedBitstreamH265Context *h265 = ctx->priv_data;
     const H265RawSPS *sps;
@@ -1728,9 +1728,8 @@ static int FUNC(sei_buffering_period)
     return 0;
 }
 
-static int FUNC(sei_pic_timing)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIPicTiming *current, SEIMessageState *sei)
+SEI_FUNC(sei_pic_timing, (CodedBitstreamContext *ctx, RWContext *rw,
+                          H265RawSEIPicTiming *current, SEIMessageState *sei))
 {
     CodedBitstreamH265Context *h265 = ctx->priv_data;
     const H265RawSPS *sps;
@@ -1804,9 +1803,9 @@ static int FUNC(sei_pic_timing)
     return 0;
 }
 
-static int FUNC(sei_pan_scan_rect)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIPanScanRect *current, SEIMessageState *sei)
+SEI_FUNC(sei_pan_scan_rect, (CodedBitstreamContext *ctx, RWContext *rw,
+                             H265RawSEIPanScanRect *current,
+                             SEIMessageState *sei))
 {
     int err, i;
 
@@ -1831,9 +1830,9 @@ static int FUNC(sei_pan_scan_rect)
     return 0;
 }
 
-static int FUNC(sei_recovery_point)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIRecoveryPoint *current, SEIMessageState *sei)
+SEI_FUNC(sei_recovery_point, (CodedBitstreamContext *ctx, RWContext *rw,
+                              H265RawSEIRecoveryPoint *current,
+                              SEIMessageState *sei))
 {
     int err;
 
@@ -1847,9 +1846,9 @@ static int FUNC(sei_recovery_point)
     return 0;
 }
 
-static int FUNC(film_grain_characteristics)(CodedBitstreamContext *ctx, RWContext *rw,
-                                            H265RawFilmGrainCharacteristics *current,
-                                            SEIMessageState *state)
+SEI_FUNC(film_grain_characteristics, (CodedBitstreamContext *ctx, RWContext *rw,
+                                      H265RawFilmGrainCharacteristics *current,
+                                      SEIMessageState *state))
 {
     CodedBitstreamH265Context *h265 = ctx->priv_data;
     const H265RawSPS *sps = h265->active_sps;
@@ -1912,9 +1911,9 @@ static int FUNC(film_grain_characteristics)(CodedBitstreamContext *ctx, RWContex
     return 0;
 }
 
-static int FUNC(sei_display_orientation)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIDisplayOrientation *current, SEIMessageState *sei)
+SEI_FUNC(sei_display_orientation, (CodedBitstreamContext *ctx, RWContext *rw,
+                                   H265RawSEIDisplayOrientation *current,
+                                   SEIMessageState *sei))
 {
     int err;
 
@@ -1931,9 +1930,9 @@ static int FUNC(sei_display_orientation)
     return 0;
 }
 
-static int FUNC(sei_active_parameter_sets)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIActiveParameterSets *current, SEIMessageState *sei)
+SEI_FUNC(sei_active_parameter_sets, (CodedBitstreamContext *ctx, RWContext *rw,
+                                     H265RawSEIActiveParameterSets *current,
+                                     SEIMessageState *sei))
 {
     CodedBitstreamH265Context *h265 = ctx->priv_data;
     const H265RawVPS *vps;
@@ -1968,9 +1967,9 @@ static int FUNC(sei_active_parameter_sets)
     return 0;
 }
 
-static int FUNC(sei_decoded_picture_hash)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIDecodedPictureHash *current, SEIMessageState *sei)
+SEI_FUNC(sei_decoded_picture_hash, (CodedBitstreamContext *ctx, RWContext *rw,
+                                    H265RawSEIDecodedPictureHash *current,
+                                    SEIMessageState *sei))
 {
     CodedBitstreamH265Context *h265 = ctx->priv_data;
     const H265RawSPS *sps = h265->active_sps;
@@ -2000,9 +1999,8 @@ static int FUNC(sei_decoded_picture_hash)
     return 0;
 }
 
-static int FUNC(sei_time_code)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEITimeCode *current, SEIMessageState *sei)
+SEI_FUNC(sei_time_code, (CodedBitstreamContext *ctx, RWContext *rw,
+                         H265RawSEITimeCode *current, SEIMessageState *sei))
 {
     int err, i;
 
@@ -2051,9 +2049,9 @@ static int FUNC(sei_time_code)
     return 0;
 }
 
-static int FUNC(sei_alpha_channel_info)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     H265RawSEIAlphaChannelInfo *current, SEIMessageState *sei)
+SEI_FUNC(sei_alpha_channel_info, (CodedBitstreamContext *ctx, RWContext *rw,
+                                  H265RawSEIAlphaChannelInfo *current,
+                                  SEIMessageState *sei))
 {
     int err, length;
 
diff --git a/libavcodec/cbs_h266_syntax_template.c b/libavcodec/cbs_h266_syntax_template.c
index e75f2f6971..29d9670521 100644
--- a/libavcodec/cbs_h266_syntax_template.c
+++ b/libavcodec/cbs_h266_syntax_template.c
@@ -3427,10 +3427,10 @@ static int FUNC(slice_header) (CodedBitstreamContext *ctx, RWContext *rw,
     return 0;
 }
 
-static int FUNC(sei_decoded_picture_hash) (CodedBitstreamContext *ctx,
-                                           RWContext *rw,
-                                           H266RawSEIDecodedPictureHash *
-                                           current, SEIMessageState *unused)
+SEI_FUNC(sei_decoded_picture_hash, (CodedBitstreamContext *ctx,
+                                    RWContext *rw,
+                                    H266RawSEIDecodedPictureHash *current,
+                                    SEIMessageState *unused))
 {
     int err, c_idx, i;
 
diff --git a/libavcodec/cbs_sei.h b/libavcodec/cbs_sei.h
index 4511c506cc..ec7cdb62f0 100644
--- a/libavcodec/cbs_sei.h
+++ b/libavcodec/cbs_sei.h
@@ -126,13 +126,6 @@ typedef struct SEIMessageTypeDescriptor {
     SEIMessageWriteFunction write;
 } SEIMessageTypeDescriptor;
 
-// Macro for the read/write pair.  The clumsy cast is needed because the
-// current pointer is typed in all of the read/write functions but has to
-// be void here to fit all cases.
-#define SEI_MESSAGE_RW(codec, name) \
-    .read  = (SEIMessageReadFunction) cbs_ ## codec ## _read_  ## name, \
-    .write = (SEIMessageWriteFunction)cbs_ ## codec ## _write_ ## name
-
 // End-of-list sentinel element.
 #define SEI_MESSAGE_TYPE_END { .type = -1 }
 
diff --git a/libavcodec/cbs_sei_syntax_template.c b/libavcodec/cbs_sei_syntax_template.c
index 62dd1dabaa..81448ef3f2 100644
--- a/libavcodec/cbs_sei_syntax_template.c
+++ b/libavcodec/cbs_sei_syntax_template.c
@@ -16,9 +16,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-static int FUNC(filler_payload)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawFillerPayload *current, SEIMessageState *state)
+SEI_FUNC(filler_payload, (CodedBitstreamContext *ctx, RWContext *rw,
+                          SEIRawFillerPayload *current,
+                          SEIMessageState *state))
 {
     int err, i;
 
@@ -34,9 +34,9 @@ static int FUNC(filler_payload)
     return 0;
 }
 
-static int FUNC(user_data_registered)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawUserDataRegistered *current, SEIMessageState *state)
+SEI_FUNC(user_data_registered, (CodedBitstreamContext *ctx, RWContext *rw,
+                                SEIRawUserDataRegistered *current,
+                                SEIMessageState *state))
 {
     int err, i, j;
 
@@ -66,9 +66,9 @@ static int FUNC(user_data_registered)
     return 0;
 }
 
-static int FUNC(user_data_unregistered)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawUserDataUnregistered *current, SEIMessageState *state)
+SEI_FUNC(user_data_unregistered, (CodedBitstreamContext *ctx, RWContext *rw,
+                                  SEIRawUserDataUnregistered *current,
+                                  SEIMessageState *state))
 {
     int err, i;
 
@@ -94,9 +94,10 @@ static int FUNC(user_data_unregistered)
     return 0;
 }
 
-static int FUNC(mastering_display_colour_volume)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawMasteringDisplayColourVolume *current, SEIMessageState *state)
+SEI_FUNC(mastering_display_colour_volume,
+         (CodedBitstreamContext *ctx, RWContext *rw,
+          SEIRawMasteringDisplayColourVolume *current,
+          SEIMessageState *state))
 {
     int err, c;
 
@@ -116,9 +117,9 @@ static int FUNC(mastering_display_colour_volume)
     return 0;
 }
 
-static int FUNC(content_light_level_info)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawContentLightLevelInfo *current, SEIMessageState *state)
+SEI_FUNC(content_light_level_info, (CodedBitstreamContext *ctx, RWContext *rw,
+                                    SEIRawContentLightLevelInfo *current,
+                                    SEIMessageState *state))
 {
     int err;
 
@@ -130,10 +131,10 @@ static int FUNC(content_light_level_info)
     return 0;
 }
 
-static int FUNC(alternative_transfer_characteristics)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawAlternativeTransferCharacteristics *current,
-     SEIMessageState *state)
+SEI_FUNC(alternative_transfer_characteristics,
+         (CodedBitstreamContext *ctx, RWContext *rw,
+          SEIRawAlternativeTransferCharacteristics *current,
+          SEIMessageState *state))
 {
     int err;
 
@@ -144,10 +145,10 @@ static int FUNC(alternative_transfer_characteristics)
     return 0;
 }
 
-static int FUNC(ambient_viewing_environment)
-    (CodedBitstreamContext *ctx, RWContext *rw,
-     SEIRawAmbientViewingEnvironment *current,
-     SEIMessageState *state)
+SEI_FUNC(ambient_viewing_environment,
+         (CodedBitstreamContext *ctx, RWContext *rw,
+          SEIRawAmbientViewingEnvironment *current,
+          SEIMessageState *state))
 {
     static const uint16_t max_ambient_light_value = 50000;
     int err;