Re: [Bug-tar] [PATCH] Possible off-by-one in readlink result

[Paul Eggert]

Tobias Stoeckmann wrote:

> -      size = readlinkat (parentfd, name, buffer, linklen + 1);
> +      size = readlinkat (parentfd, name, buffer, linklen);

Thanks for the bug report and patch.  Although that patch fixes the immediate 
problem, it would still have the bug that a race could cause 'tar' to create a 
tar image of a symlink that never existed.  Also, some file systems report an 
incorrect st_size on symlinks so it's not wise to trust st_size.

I noticed some other problems while fixing this, and installed the attached set 
of patches to fix what I found.  The last patch should fix the bug you reported, 
along with the untrustworthy st_size problem.

0001-tar-pacify-GCC-5.1-Wformat-signedness.patch
Description: Text Data

0002-tar-port-to-recent-gnulib.patch
Description: Text Data

0003-tar-port-d-to-longer-symlinks.patch
Description: Text Data

0004-tar-fix-symlink-race-and-symlink-transform-bug.patch
Description: Text Data