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Fixed some infinite loops that a maliciously-crafted .iso can trigger. 

These bugs exposed by American Fuzzy Lop (AFL), a powerful fuzzer.

http://lcamtuf.coredump.cx/afl/
This commit is contained in:
Ryan C. Gordon 2017-10-23 14:58:54 -04:00
parent 1c7945461d
commit 26db9376da
1 changed files with 16 additions and 5 deletions
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21
src/physfs_archiver_iso9660.c
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@ -151,18 +151,25 @@ static int iso9660LoadEntries(PHYSFS_Io *io, const int joliet,
/* recordlen = 0 -> no more entries or fill entry */
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &recordlen, 1), 0);
if (recordlen == 0)
if (recordlen > 0)
readpos += recordlen; /* ready to seek to next record. */
else
{
PHYSFS_uint64 nextpos;
/* if we are in the last sector of the directory & it's 0 -> end */
if ((dirend - 2048) <= (readpos - 1))
break; /* finished */
/* else skip to the next sector & continue; */
readpos = (((readpos - 1) / 2048) + 1) * 2048;
continue;
} /* if */
nextpos = (((readpos - 1) / 2048) + 1) * 2048;
readpos += recordlen; /* ready to seek to next record. */
/* whoops, can't make forward progress! */
BAIL_IF(nextpos == readpos, PHYSFS_ERR_CORRUPT, 0);
readpos = nextpos;
continue; /* start back at upper loop. */
} /* else */
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &extattrlen, 1), 0);
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, &extent, 4), 0);
@ -203,6 +210,10 @@ static int iso9660LoadEntries(PHYSFS_Io *io, const int joliet,
timestamp = (PHYSFS_sint64) mktime(&t);
extent += extattrlen; /* skip extended attribute record. */
/* infinite loop, corrupt file? */
BAIL_IF((extent * 2048) == dirstart, PHYSFS_ERR_CORRUPT, 0);
if (!iso9660AddEntry(io, joliet, isdir, base, fname, fnamelen,
timestamp, extent * 2048, datalen, unpkarc))
{