From 37549e94c77a94a9c32b5ae3313a3801cb66adf9 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 27 Jul 2014 07:26:01 +0930 Subject: [PATCH] sysfs: disallow world-writable files. This check was introduced in 2006 by Alexey Dobriyan (9774a1f54f173) for module parameters; we removed it when we unified the check into VERIFY_OCTAL_PERMISSIONS() as sysfs didn't have the same requirement. Now all those users are fixed, reintroduce it. Cc: Alexey Dobriyan Cc: Dave Jones Cc: Joe Perches Signed-off-by: Rusty Russell --- include/linux/kernel.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 4c52907a6d8b..43e1c6a9683e 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -849,5 +849,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } /* User perms >= group perms >= other perms */ \ BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \ BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \ + /* Other writable? Generally considered a bad idea. */ \ + BUILD_BUG_ON_ZERO((perms) & 2) + \ (perms)) #endif -- 2.39.5