| Patrick Williams | d8c66bc | 2016-06-20 12:57:21 -0500 | [diff] [blame] | 1 | Multiple integer overflows in the XML_GetBuffer function in Expat |
| 2 | through 2.1.0, allow remote attackers to cause a denial of service |
| 3 | (heap-based buffer overflow) or possibly have unspecified other |
| 4 | impact via crafted XML data. |
| 5 | |
| 6 | CVSSv2: (AV:N/AC:M/Au:N/C:P/I:P/A:P) |
| 7 | |
| 8 | CVE: CVE-2015-1283 |
| 9 | Upstream-Status: Backport |
| 10 | |
| 11 | Signed-off-by: Eric Rahm <erahm@mozilla.com> |
| 12 | Signed-off-by: Zhixiong Chi <zhixiong.chi@windirver.com> |
| 13 | |
| 14 | Index: expat-2.1.0/lib/xmlparse.c |
| 15 | =================================================================== |
| 16 | --- expat-2.1.0.orig/lib/xmlparse.c 2012-03-11 13:13:12.000000000 +0800 |
| 17 | +++ expat-2.1.0/lib/xmlparse.c 2015-12-23 10:29:07.347361329 +0800 |
| 18 | @@ -1678,6 +1678,12 @@ |
| 19 | void * XMLCALL |
| 20 | XML_GetBuffer(XML_Parser parser, int len) |
| 21 | { |
| 22 | +/* BEGIN MOZILLA CHANGE (sanity check len) */ |
| 23 | + if (len < 0) { |
| 24 | + errorCode = XML_ERROR_NO_MEMORY; |
| 25 | + return NULL; |
| 26 | + } |
| 27 | +/* END MOZILLA CHANGE */ |
| 28 | switch (ps_parsing) { |
| 29 | case XML_SUSPENDED: |
| 30 | errorCode = XML_ERROR_SUSPENDED; |
| 31 | @@ -1689,8 +1695,13 @@ |
| 32 | } |
| 33 | |
| 34 | if (len > bufferLim - bufferEnd) { |
| 35 | - /* FIXME avoid integer overflow */ |
| 36 | int neededSize = len + (int)(bufferEnd - bufferPtr); |
| 37 | +/* BEGIN MOZILLA CHANGE (sanity check neededSize) */ |
| 38 | + if (neededSize < 0) { |
| 39 | + errorCode = XML_ERROR_NO_MEMORY; |
| 40 | + return NULL; |
| 41 | + } |
| 42 | +/* END MOZILLA CHANGE */ |
| 43 | #ifdef XML_CONTEXT_BYTES |
| 44 | int keep = (int)(bufferPtr - buffer); |
| 45 | |
| 46 | @@ -1719,7 +1730,15 @@ |
| 47 | bufferSize = INIT_BUFFER_SIZE; |
| 48 | do { |
| 49 | bufferSize *= 2; |
| 50 | - } while (bufferSize < neededSize); |
| 51 | +/* BEGIN MOZILLA CHANGE (prevent infinite loop on overflow) */ |
| 52 | + } while (bufferSize < neededSize && bufferSize > 0); |
| 53 | +/* END MOZILLA CHANGE */ |
| 54 | +/* BEGIN MOZILLA CHANGE (sanity check bufferSize) */ |
| 55 | + if (bufferSize <= 0) { |
| 56 | + errorCode = XML_ERROR_NO_MEMORY; |
| 57 | + return NULL; |
| 58 | + } |
| 59 | +/* END MOZILLA CHANGE */ |
| 60 | newBuf = (char *)MALLOC(bufferSize); |
| 61 | if (newBuf == 0) { |
| 62 | errorCode = XML_ERROR_NO_MEMORY; |