From 579ff6922089cbbbd179619e40e622e279bd719f Mon Sep 17 00:00:00 2001
From: Martijn van Beurden <mvanb1@gmail.com>
Date: Wed, 3 Aug 2022 13:52:19 +0200
Subject: [PATCH] flac: Add and use _nofree variants of safe_realloc functions
Parts of the code use realloc like
x = safe_realloc(x, somesize);
when this is the case, the safe_realloc variant used must free the
old memory block in case it fails, otherwise it will leak. However,
there are also instances in the code where handling is different:
if (0 == (x = safe_realloc(y, somesize)))
return false
in this case, y should not be freed, as y is not set to NULL we
could encounter double frees. Here the safe_realloc_nofree
functions are used.
Upstream-Status: Backport [https://github.com/xiph/flac/commit/21fe95ee828b0b9b944f6aa0bb02d24fbb981815]
CVE: CVE-2020-22219
Signed-off-by: Meenali Gupta <meenali.gupta@windriver.com>
---
include/share/alloc.h | 41 +++++++++++++++++++++++++++++++----
src/flac/encode.c | 4 ++--
src/flac/foreign_metadata.c | 2 +-
src/libFLAC/bitwriter.c | 2 +-
src/libFLAC/metadata_object.c | 2 +-
src/plugin_common/tags.c | 2 +-
src/share/utf8/iconvert.c | 2 +-
7 files changed, 44 insertions(+), 11 deletions(-)
diff --git a/include/share/alloc.h b/include/share/alloc.h
index 914de9b..55bdd1d 100644
--- a/include/share/alloc.h
+++ b/include/share/alloc.h
@@ -161,17 +161,30 @@ static inline void *safe_realloc_(void *ptr, size_t size)
free(oldptr);
return newptr;
}
-static inline void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
+static inline void *safe_realloc_nofree_add_2op_(void *ptr, size_t size1, size_t size2)
+{
+ size2 += size1;
+ if(size2 < size1)
+ return 0;
+ return realloc(ptr, size2);
+}
+
+static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1) {
free(ptr);
return 0;
}
- return realloc(ptr, size2);
+ size3 += size2;
+ if(size3 < size2) {
+ free(ptr);
+ return 0;
+ }
+ return safe_realloc_(ptr, size3);
}
-static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
+static inline void *safe_realloc_nofree_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
{
size2 += size1;
if(size2 < size1)
@@ -182,7 +195,7 @@ static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2,
return realloc(ptr, size3);
}
-static inline void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
+static inline void *safe_realloc_nofree_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
{
size2 += size1;
if(size2 < size1)
@@ -205,6 +218,15 @@ static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
return safe_realloc_(ptr, size1*size2);
}
+static inline void *safe_realloc_nofree_mul_2op_(void *ptr, size_t size1, size_t size2)
+{
+ if(!size1 || !size2)
+ return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
+ if(size1 > SIZE_MAX / size2)
+ return 0;
+ return realloc(ptr, size1*size2);
+}
+
/* size1 * (size2 + size3) */
static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
{
@@ -216,4 +238,15 @@ static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2,
return safe_realloc_mul_2op_(ptr, size1, size2);
}
+/* size1 * (size2 + size3) */
+static inline void *safe_realloc_nofree_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
+{
+ if(!size1 || (!size2 && !size3))
+ return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
+ size2 += size3;
+ if(size2 < size3)
+ return 0;
+ return safe_realloc_nofree_mul_2op_(ptr, size1, size2);
+}
+
#endif
diff --git a/src/flac/encode.c b/src/flac/encode.c
index a9b907f..f87250c 100644
--- a/src/flac/encode.c
+++ b/src/flac/encode.c
@@ -1743,10 +1743,10 @@ static void static_metadata_clear(static_metadata_t *m)
static FLAC__bool static_metadata_append(static_metadata_t *m, FLAC__StreamMetadata *d, FLAC__bool needs_delete)
{
void *x;
- if(0 == (x = safe_realloc_muladd2_(m->metadata, sizeof(*m->metadata), /*times (*/m->num_metadata, /*+*/1/*)*/)))
+ if(0 == (x = safe_realloc_nofree_muladd2_(m->metadata, sizeof(*m->metadata), /*times (*/m->num_metadata, /*+*/1/*)*/)))
return false;
m->metadata = (FLAC__StreamMetadata**)x;
- if(0 == (x = safe_realloc_muladd2_(m->needs_delete, sizeof(*m->needs_delete), /*times (*/m->num_metadata, /*+*/1/*)*/)))
+ if(0 == (x = safe_realloc_nofree_muladd2_(m->needs_delete, sizeof(*m->needs_delete), /*times (*/m->num_metadata, /*+*/1/*)*/)))
return false;
m->needs_delete = (FLAC__bool*)x;
m->metadata[m->num_metadata] = d;
diff --git a/src/flac/foreign_metadata.c b/src/flac/foreign_metadata.c
index 9ad9c18..fdfb3cf 100644
--- a/src/flac/foreign_metadata.c
+++ b/src/flac/foreign_metadata.c
@@ -75,7 +75,7 @@ static FLAC__bool copy_data_(FILE *fin, FILE *fout, size_t size, const char **er
static FLAC__bool append_block_(foreign_metadata_t *fm, FLAC__off_t offset, FLAC__uint32 size, const char **error)
{
- foreign_block_t *fb = safe_realloc_muladd2_(fm->blocks, sizeof(foreign_block_t), /*times (*/fm->num_blocks, /*+*/1/*)*/);
+ foreign_block_t *fb = safe_realloc_nofree_muladd2_(fm->blocks, sizeof(foreign_block_t), /*times (*/fm->num_blocks, /*+*/1/*)*/);
if(fb) {
fb[fm->num_blocks].offset = offset;
fb[fm->num_blocks].size = size;
diff --git a/src/libFLAC/bitwriter.c b/src/libFLAC/bitwriter.c
index 6e86585..a510b0d 100644
--- a/src/libFLAC/bitwriter.c
+++ b/src/libFLAC/bitwriter.c
@@ -124,7 +124,7 @@ FLAC__bool bitwriter_grow_(FLAC__BitWriter *bw, uint32_t bits_to_add)
FLAC__ASSERT(new_capacity > bw->capacity);
FLAC__ASSERT(new_capacity >= bw->words + ((bw->bits + bits_to_add + FLAC__BITS_PER_WORD - 1) / FLAC__BITS_PER_WORD));
- new_buffer = safe_realloc_mul_2op_(bw->buffer, sizeof(bwword), /*times*/new_capacity);
+ new_buffer = safe_realloc_nofree_mul_2op_(bw->buffer, sizeof(bwword), /*times*/new_capacity);
if(new_buffer == 0)
return false;
bw->buffer = new_buffer;
diff --git a/src/libFLAC/metadata_object.c b/src/libFLAC/metadata_object.c
index de8e513..aef65be 100644
--- a/src/libFLAC/metadata_object.c
+++ b/src/libFLAC/metadata_object.c
@@ -98,7 +98,7 @@ static FLAC__bool free_copy_bytes_(FLAC__byte **to, const FLAC__byte *from, uint
/* realloc() failure leaves entry unchanged */
static FLAC__bool ensure_null_terminated_(FLAC__byte **entry, uint32_t length)
{
- FLAC__byte *x = safe_realloc_add_2op_(*entry, length, /*+*/1);
+ FLAC__byte *x = safe_realloc_nofree_add_2op_(*entry, length, /*+*/1);
if (x != NULL) {
x[length] = '\0';
*entry = x;
diff --git a/src/plugin_common/tags.c b/src/plugin_common/tags.c
index ae440c5..dfa10d3 100644
--- a/src/plugin_common/tags.c
+++ b/src/plugin_common/tags.c
@@ -317,7 +317,7 @@ FLAC__bool FLAC_plugin__tags_add_tag_utf8(FLAC__StreamMetadata *tags, const char
const size_t value_len = strlen(value);
const size_t separator_len = strlen(separator);
FLAC__byte *new_entry;
- if(0 == (new_entry = safe_realloc_add_4op_(entry->entry, entry->length, /*+*/value_len, /*+*/separator_len, /*+*/1)))
+ if(0 == (new_entry = safe_realloc_nofree_add_4op_(entry->entry, entry->length, /*+*/value_len, /*+*/separator_len, /*+*/1)))
return false;
memcpy(new_entry+entry->length, separator, separator_len);
entry->length += separator_len;
diff --git a/src/share/utf8/iconvert.c b/src/share/utf8/iconvert.c
index 8ab53c1..876c06e 100644
--- a/src/share/utf8/iconvert.c
+++ b/src/share/utf8/iconvert.c
@@ -149,7 +149,7 @@ int iconvert(const char *fromcode, const char *tocode,
iconv_close(cd1);
return ret;
}
- newbuf = safe_realloc_add_2op_(utfbuf, (ob - utfbuf), /*+*/1);
+ newbuf = safe_realloc_nofree_add_2op_(utfbuf, (ob - utfbuf), /*+*/1);
if (!newbuf)
goto fail;
ob = (ob - utfbuf) + newbuf;
--
2.40.0