[FFmpeg-devel] [PATCH v2] libavformat/mpegts.c: pat_cb(): ensure all PIDs are valid

Scott Theisen scott.the.elm at gmail.com
Mon Jun 30 07:29:52 EEST 2025


ISO/IEC 13818-1:2021 specifies a valid range of [0x0010, 0x1FFE] in
§ 2.4.4.6 Semantic definition of fields in program association section
and Table 2-3 – PID table

ts->current_pid is always 0 since that is the PID for the PAT.
---

Marton Balint,

You were correct that the crash MythTV was trying to fix was already fixed by
the if (pmt_pid == ts->current_pid) test.

I don't think the logging I originally added was necessary, so I have removed
it for this version.

Regards,

Scott Theisen

---
 libavformat/mpegts.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index deb69a0548..62bcd2982c 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -2590,7 +2590,7 @@ static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
             break;
         pmt_pid &= 0x1fff;
 
-        if (pmt_pid == ts->current_pid)
+        if (pmt_pid <= 0x000F || pmt_pid == 0x1FFF)
             break;
 
         av_log(ts->stream, AV_LOG_TRACE, "sid=0x%x pid=0x%x\n", sid, pmt_pid);
-- 
2.50.0



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