From 58f86cc89c3372d3e61d5b71e5513ec5a0b02848 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 24 Mar 2014 12:00:34 +1030 Subject: VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms. Summary of http://lkml.org/lkml/2014/3/14/363 : Ted: module_param(queue_depth, int, 444) Joe: 0444! Rusty: User perms >= group perms >= other perms? Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2? Side effect of stricter permissions means removing the unnecessary S_IFREG from several callers. Note that the BUILD_BUG_ON_ZERO((perm) & 2) test was removed: a fair number of drivers fail this test, so that will be the debate for a future patch. Suggested-by: Joe Perches Acked-by: Bjorn Helgaas for drivers/pci/slot.c Acked-by: Greg Kroah-Hartman Cc: Miklos Szeredi Cc: Mark Fasheh Cc: Joel Becker Signed-off-by: Rusty Russell --- include/linux/kernel.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 471090093c67..4679eddc110a 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -842,4 +842,12 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD #endif +/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ +#define VERIFY_OCTAL_PERMISSIONS(perms) \ + (BUILD_BUG_ON_ZERO((perms) < 0) + \ + BUILD_BUG_ON_ZERO((perms) > 0777) + \ + /* User perms >= group perms >= other perms */ \ + BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \ + BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \ + (perms)) #endif -- cgit v1.2.3