oss-sec mailing list archives
Re: Fixing the glibc runtime linker
From: Rich Felker <dalias () libc org>
Date: Fri, 20 Feb 2015 02:57:56 -0500
On Thu, Feb 19, 2015 at 11:50:37PM -0800, Paul Pluzhnikov wrote:
On Thu, Feb 19, 2015 at 11:34 PM, Rich Felker <dalias () libc org> wrote:I don't see how you think this is a security issue at all.I think the point is that 'system(argv[1])' is a hard mistake to make by accident, but empty or relative RPATH is easy, and is not immediately discoverable: you have to run 'readelf -d a.out' and then think about what you see.
How is an empty or relative rpath easy? You have to explicitly add -Wl,-rpath,[whatever] to the linker command line. Most people don't even know this option exists, and those who do need to understand how it works or they're not going to get results that even work. If an rpath is needed and you accidentally make it cwd-relative rather than absolute or origin-relative, running your program is just going to fail when you're not in the 'right' working directory; this is such obvious breakage that it should be caught immediately by even basic testing. Rich
Current thread:
- Fixing the glibc runtime linker Tim Brown (Feb 19)
- Re: Fixing the glibc runtime linker Stuart Gathman (Feb 19)
- Re: Fixing the glibc runtime linker Tim Brown (Feb 19)
- Re: Fixing the glibc runtime linker Paul Pluzhnikov (Feb 19)
- Re: Fixing the glibc runtime linker Tim Brown (Feb 19)
- Re: Fixing the glibc runtime linker Paul Pluzhnikov (Feb 19)
- Re: Fixing the glibc runtime linker Rich Felker (Feb 19)
- Re: Fixing the glibc runtime linker Paul Pluzhnikov (Feb 19)
- Re: Fixing the glibc runtime linker Rich Felker (Feb 19)
- Re: Fixing the glibc runtime linker Paul Pluzhnikov (Feb 20)
- Re: Fixing the glibc runtime linker Tim Brown (Feb 20)
- Re: Fixing the glibc runtime linker Rich Felker (Feb 20)
- Re: Fixing the glibc runtime linker Paul Pluzhnikov (Feb 20)
- Re: Fixing the glibc runtime linker Rich Felker (Feb 20)
- Re: Fixing the glibc runtime linker Tim Brown (Feb 19)
- Re: Fixing the glibc runtime linker Stuart Gathman (Feb 19)
- Re: Fixing the glibc runtime linker Paul Pluzhnikov (Feb 20)
- Re: Fixing the glibc runtime linker Rich Felker (Feb 21)