On Mon, Jan 26, 2015 at 04:15:26PM -0800, Kees Cook wrote: > > > > akpm3:/usr/src/25> grep -r map_files Documentation > > If akpm's comments weren't clear: this needs to be fixed. Everything > in /proc should appear in Documentation. I'll do that. > > The 640708a2cff7f81 changelog says: > > > > : This one behaves similarly to the /proc/<pid>/fd/ one - it contains > > : symlinks one for each mapping with file, the name of a symlink is > > : "vma->vm_start-vma->vm_end", the target is the file. Opening a symlink > > : results in a file that point exactly to the same inode as them vma's one. > > : > > : For example the ls -l of some arbitrary /proc/<pid>/map_files/ > > : > > : | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so > > : | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1 > > : | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0 > > : | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so > > : | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so > > How is mmap offset represented in this output? We're printing vm_area_struct:[vm_start;vm_end] only. > > afacit this info is also available in /proc/pid/maps, so things > > shouldn't get worse if the /proc/pid/map_files permissions are at least > > as restrictive as the /proc/pid/maps permissions. Is that the case? > > (Please add to changelog). > > Both maps and map_files uses ptrace_may_access (via mm_acces) with > PTRACE_MODE_READ, so I'm happy from a info leak perspective. > > Are mount namespaces handled in this output? Could you clarify this moment, i'm not sure i get it. > > > There's one other problem here: we're assuming that the map_files > > implementation doesn't have bugs. If it does have bugs then relaxing > > permissions like this will create new vulnerabilities. And the > > map_files implementation is surprisingly complex. Is it bug-free? -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
