[PING] [PATCH] Enforce NAME_MAX in readdir_r

[Florian Weimer]

On 10/12/2012 03:21 PM, Florian Weimer wrote:
> This patch enforces the NAME_MAX limit in readdir_r.  The situation is
> similar to getwd, realpath, and others with PATH_MAX—Linux does not
> actually enforce the limit we've baked into the ABI.  User code does not
> take this into account, so we have to check for the NAME_MAX limit and
> skip large file names.  Error reporting is delayed until the end of the
> directory, so that we do not truncate it on the first long name.
>
> This patch supersedes the GETDENTS_64BIT_ALIGNED workaround for the
> issue reported in bug 11333.  On architectures which define this macro,
> the kernel-supplied string is sometimes truncated by glibc and not
> properly NUL-terminated.  After the patch, we look at the actual string
> length and check if it fits into the caller-supplied buffer.  This works
> on all architectures, so the architecture-specific macro is no longer
> necessary.
>
> I did not touch readdir because it does not appear to be directly
> harmful to return large names in that function because we manage the
> buffer and the system call has a proper length check.
>
> I regression-tested this on x86_64-redhat-linux-gnu.

Ping?

Patch is at: <http://sourceware.org/ml/libc-alpha/2012-10/msg00377.html>


-- 
Florian Weimer / Red Hat Product Security Team