Oracle Java Runtime Environment – Heap Corruption During TTF font Rendering in GlyphIterator::setCurrGlyphID
A heap corruption was observed in Oracle Java Runtime Environment version 8u202 (latest at the time of this writing) while fuzz-testing the processing of TrueType fonts. It manifests itself in the form of the following (or similar) crash: --- cut --- $ bin/java -cp . DisplaySfntFont test.ttf Iteration (0,0) # # A fatal error has been detected by the Java Runtime Environment: # # SIGSEGV (0xb) at pc=0x00007f7285b39824, pid=234398, tid=0x00007f7286683700 # # JRE version: Java(TM) SE Runtime Environment (8.0_202-b08) (build 1.8.0_202-b08) # Java VM: Java HotSpot(TM) 64-Bit Server VM (25.202-b08 mixed mode linux-amd64 compressed oops) # Problematic frame: # C [libc.so.6+0x77824]# [ timer expired, abort... ] Aborted --- cut --- The crash reproduces on both Windows and Linux platforms. On Linux, it can be also triggered with the MALLOC_CHECK_=3 environment variable: --- cut --- $ MALLOC_CHECK_=3 bin/java -cp . DisplaySfntFont test.ttf Iteration (0,0) *** Error in `bin/java': free(): invalid pointer: 0x0000000002876320 *** ======= Backtrace: ========= /lib/x86_64-linux-gnu/libc.so.6(+0x70bcb)[0x7f84185edbcb] /lib/x86_64-linux-gnu/libc.so.6(+0x76f96)[0x7f84185f3f96] jre/8u202/lib/amd64/libfontmanager.so(+0x1d2b2)[0x7f83ddc672b2] jre/8u202/lib/amd64/libfontmanager.so(+0x27ff4)[0x7f83ddc71ff4] jre/8u202/lib/amd64/libfontmanager.so(+0x866f)[0x7f83ddc5266f] jre/8u202/lib/amd64/libfontmanager.so(Java_sun_font_SunLayoutEngine_nativeLayout+0x230)[0x7f83ddc78990] [0x7f84076306c7] ======= Memory map: ======== 00400000-00401000 r-xp 00000000 fe:01 20840680 jre/8u202/bin/java 00600000-00601000 r--p 00000000 fe:01 20840680 jre/8u202/bin/java 00601000-00602000 rw-p 00001000 fe:01 20840680 jre/8u202/bin/java 023ba000-028d9000 rw-p 00000000 00:00 0 [heap] 3d1a00000-3fba00000 rw-p 00000000 00:00 0 3fba00000-670900000 ---p 00000000 00:00 0 670900000-685900000 rw-p 00000000 00:00 0 685900000-7c0000000 ---p 00000000 00:00 0 7c0000000-7c00c0000 rw-p 00000000 00:00 0 7c00c0000-800000000 ---p 00000000 00:00 0 [...] --- cut --- ... under Valgrind: --- cut --- $ valgrind bin/java -cp . DisplaySfntFont test.ttf [...] ==245623== Invalid write of size 2 ==245623== at 0x40BF2750: GlyphIterator::setCurrGlyphID(unsigned short) (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C0C089: SingleSubstitutionFormat1Subtable::process(LEReferenceTo<SingleSubstitutionFormat1Subtable> const&, GlyphIterator*, LEErrorCode&, LEGlyphFilter const*) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C0C4A4: SingleSubstitutionSubtable::process(LEReferenceTo<SingleSubstitutionSubtable> const&, GlyphIterator*, LEErrorCode&, LEGlyphFilter const*) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BF47E5: GlyphSubstitutionLookupProcessor::applySubtable(LEReferenceTo<LookupSubtable> const&, unsigned short, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const [clone .part.11] (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C01DCE: LookupProcessor::applyLookupTable(LEReferenceTo<LookupTable> const&, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C02FBA: LookupProcessor::applySingleLookup(unsigned short, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BEBC9C: ContextualSubstitutionBase::applySubstitutionLookups(LookupProcessor const*, LEReferenceToArrayOf<SubstitutionLookupRecord> const&, unsigned short, GlyphIterator*, LEFontInstance const*, int, LEErrorCode&) (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BEE766: ChainingContextualSubstitutionFormat3Subtable::process(LETableReference const&, LookupProcessor const*, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BEE8E3: ChainingContextualSubstitutionSubtable::process(LEReferenceTo<ChainingContextualSubstitutionSubtable> const&, LookupProcessor const*, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BF475B: GlyphSubstitutionLookupProcessor::applySubtable(LEReferenceTo<LookupSubtable> const&, unsigned short, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const [clone .part.11] (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C01DCE: LookupProcessor::applyLookupTable(LEReferenceTo<LookupTable> const&, GlyphIterator*, LEFontInstance const*, LEErrorCode&) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C02EAB: LookupProcessor::process(LEGlyphStorage&, GlyphPositionAdjustments*, char, LEReferenceTo<GlyphDefinitionTableHeader> const&, LEFontInstance const*, LEErrorCode&) const (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== Address 0x3f68a55c is 4 bytes before a block of size 104 alloc'd ==245623== at 0x4C2BBEF: malloc (vg_replace_malloc.c:299) ==245623== by 0x40BFD4CF: LEGlyphStorage::allocateGlyphArray(int, char, LEErrorCode&) (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BE875A: ArabicOpenTypeLayoutEngine::characterProcessing(unsigned short const*, int, int, int, char, unsigned short*&, LEGlyphStorage&, LEErrorCode&) (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C0815F: OpenTypeLayoutEngine::computeGlyphs(unsigned short const*, int, int, int, char, LEGlyphStorage&, LEErrorCode&) (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40BFE55D: LayoutEngine::layoutChars(unsigned short const*, int, int, int, char, float, float, LEErrorCode&) (in jre/8u202/lib/amd64/libfontmanager.so) ==245623== by 0x40C0E91F: Java_sun_font_SunLayoutEngine_nativeLayout (in jre/8u202/lib/amd64/libfontmanager.so) [...] --- cut --- or with AFL's libdislocator under gdb: --- cut --- Continuing. Iteration (0,0) *** [AFL] bad allocator canary on free() *** Thread 2 "java" received signal SIGABRT, Aborted. [...] Stopped reason: SIGABRT __GI_raise (sig=sig@entry=0x6) at ../sysdeps/unix/sysv/linux/raise.c:51 51 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. gdb$ where #0 __GI_raise (sig=sig@entry=0x6) at ../sysdeps/unix/sysv/linux/raise.c:51 #1 0x00007ffff72313fa in __GI_abort () at abort.c:89 #2 0x00007ffff7bd651c in free () from libdislocator/libdislocator.so #3 0x00007fffb892f2b2 in LEGlyphStorage::reset() () from jre/8u202/lib/amd64/libfontmanager.so #4 0x00007fffb8939ff4 in OpenTypeLayoutEngine::~OpenTypeLayoutEngine() () from jre/8u202/lib/amd64/libfontmanager.so #5 0x00007fffb891a66f in ArabicOpenTypeLayoutEngine::~ArabicOpenTypeLayoutEngine() () from jre/8u202/lib/amd64/libfontmanager.so #6 0x00007fffb8940990 in Java_sun_font_SunLayoutEngine_nativeLayout () from jre/8u202/lib/amd64/libfontmanager.so #7 0x00007fffe5e376c7 in ?? () #8 0x0000000000000000 in ?? () --- cut --- On Windows, the crash also reliably reproduces with PageHeap enabled for the java.exe process: --- cut --- (1184.4c60): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. fontmanager!Java_sun_java2d_loops_DrawGlyphListLCD_DrawGlyphListLCD+0x14bf: 00007ffa`0d6291bf 428124810000ffff and dword ptr [rcx+r8*4],0FFFF0000h ds:00000000`39663ffc=???????? --- cut --- We have encountered crashes in the libfontmanager!GlyphIterator::setCurrGlyphID function while trying to write before and after a heap allocation. Attached with this report are two mutated testcases (for the buffer under- and overflow), and a simple Java program used to reproduce the vulnerability by loading TrueType fonts specified through a command-line parameter. Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/46723.zip |