tree 80ad7ecf85ece7a46133fd23b150d05a4074da5a
parent fbb1816942c04429e85dbf4c1a080accc534299e
author Jann Horn <jann@thejh.net> 1441838310 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1441916941 -0700

fs: Don't dump core if the corefile would become world-readable.

On a filesystem like vfat, all files are created with the same owner
and mode independent of who created the file. When a vfat filesystem
is mounted with root as owner of all files and read access for everyone,
root's processes left world-readable coredumps on it (but other
users' processes only left empty corefiles when given write access
because of the uid mismatch).

Given that the old behavior was inconsistent and insecure, I don't see
a problem with changing it. Now, all processes refuse to dump core unless
the resulting corefile will only be readable by their owner.

Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>