DSF ID3 tags hitting 4k size limit

Here's a change to dynamically allocate the DSD ID3 tag buffer. Pretty much anything with cover art is going to exceed the existing, static 4k limit... Here's a change to dynamically allocate the buffer and sanity check it at some upper limit. I rather arbitrarily pulled 256k out of thin air just to keep a corrupt file from causing it to trying to allocate a buffer larger than available memory.

DSF ID3 tags hitting 4k size limit
35db88af · Jan Brittenson · Max Kellermann · e38faca4 · 35db88af · 35db88af
Commit 35db88af authored Dec 22, 2014 by Jan Brittenson Committed by Max Kellermann Dec 23, 2014
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Showing with 14 additions and 6 deletions

NEWS NEWS +2 -0

DsdLib.cxx src/decoder/plugins/DsdLib.cxx +12 -6

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--- a/NEWS
+++ b/NEWS
 ver 0.19.8 (not yet released)
+* decoder
+  - dsdiff, dsf: allow ID3 tags larger than 4 kB

 ver 0.19.7 (2014/12/17)
 * input

--- a/src/decoder/plugins/DsdLib.cxx
+++ b/src/decoder/plugins/DsdLib.cxx
@@ -29,6 +29,7 @@
 #include "input/InputStream.hxx"
 #include "tag/TagId3.hxx"
 #include "util/Error.hxx"
+#include "util/Alloc.hxx"

 #include <string.h>

@@ -123,22 +124,27 @@ dsdlib_tag_id3(InputStream &is,

 	const id3_length_t count = size - offset;

-	/* Check and limit id3 tag size to prevent a stack overflow */
-	id3_byte_t dsdid3[4096];
-	if (count == 0 || count > sizeof(dsdid3))
+	if (count < 10 || count > 256*1024)
 		return;

-	if (!decoder_read_full(nullptr, is, dsdid3, count))
+	id3_byte_t *const id3_buf = static_cast<id3_byte_t*>(xalloc(count));
+
+	if (!decoder_read_full(nullptr, is, id3_buf, count)) {
+		free(id3_buf);
 		return;
+	}

-	struct id3_tag *id3_tag = id3_tag_parse(dsdid3, count);
-	if (id3_tag == nullptr)
+	struct id3_tag *id3_tag = id3_tag_parse(id3_buf, count);
+	if (id3_tag == nullptr) {
+		free(id3_buf);
 		return;
+	}

 	scan_id3_tag(id3_tag, handler, handler_ctx);

 	id3_tag_delete(id3_tag);

+	free(id3_buf);
 	return;
 }
 #endif