<i18n dev> RFR(xs): 8165936: Potential Heap buffer overflow when seaching timezone info files

[Langer, Christoph]

Hi Thomas,

your change looks good. I'm also forwarding this to i18n-dev as issues in TimeZone implementation are mostly handled there.

One remark: Can you take the opportunity to also remove the blank between the cast and malloc in line 150: "(struct dirent64 *) malloc..."?

Unfortunately I'm no reviewer, so you still need an official review.

Best regards
Christoph

> -----Original Message-----
> From: core-libs-dev [mailto:core-libs-dev-bounces at openjdk.java.net] On Behalf
> Of Thomas Stüfe
> Sent: Dienstag, 13. September 2016 12:54
> To: Java Core Libs <core-libs-dev at openjdk.java.net>
> Subject: RFR(xs): 8165936: Potential Heap buffer overflow when seaching
> timezone info files
> 
> Dear all,
> 
> please take a look at this small change:
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8165936
> Webrev:
> http://cr.openjdk.java.net/~stuefe/webrevs/8165936-Potential-Heap-buffer-
> overflow-when-seaching-timezone-info-files/webrev.00/webrev/
> 
> readdir_r is used to iterate over the content of a system directory, but
> the buffer passed to it is too small: Its size should include the size of
> the dirent structure itself (minus the d_name member).
> 
> The fix also now checks the return code of pathconf(), and if pathconf()
> returns an error, falls back to the NAME_MAX compile time constant.
> Finally, it imposes a minimum size for the buffer, because on older System
> V systems NAME_MAX may be surprisingly small and readdir_r will not check
> the output buffer size. I think it is better to err on the safe side here.
> 
> Kind Regards, Thomas