346250 - nsDiskCacheMap.cpp closes wrong filedescriptor (when metadata is written to a separate file!)

Status: VERIFIED FIXED

(Core :: Networking: Cache, defect)

Description

[Alfred Kayser]

At line:
http://lxr.mozilla.org/mozilla/source/netwerk/cache/src/nsDiskCacheMap.cpp#792
792         PRStatus err = PR_Close(mMapFD);
The mMapFD is wrong, this should be 'fd' to close the file opened for writing/saving the metadata of that specific cache entry.

Luckely, cacheEntry metadata never seems to be bigger than 16K so it always gets stored in a blockfile and not as a separate file. Never say never, and metadata could potentially be bigger than 16K, and then the diskCache code would fails miserably because the map file is closed.

So, either fix the line to close the correct file, or remove the metadata as separate file for cache entries. The first is most simple and correct, the second reduces codesize (and dangers of unused/untested code) but adds a limit to metadata size of cacheEntries.

P.s., not tested, but can someone enforce to have very big cacheEntry metadata and then so force the diskCache to crash?

Comment 1

[Alfred Kayser]

Attachment: Fix to close the correct file handle

Comment 2

[Darin Fisher]

Comment on attachment 231063 [details] [diff] [review]
Fix to close the correct file handle

wow, r=darin

Comment 3

[Boris Zbarsky [:bzbarsky]]

Fixed on trunk.  Do we need this on the 1.8 branch?

Comment 4

[Alfred Kayser]

I think so, because this could potentially be a DOS issue.