From 3ea4331c60be3eee4c97e5ddabad95399f879b76 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Thu, 25 Jun 2015 15:01:47 -0700 Subject: [PATCH] check_syslog_permissions() cleanup Patch fixes drawbacks in heck_syslog_permissions() noticed by AKPM: "from_file handling makes me cry. That's not a boolean - it's an enumerated value with two values currently defined. But the code in check_syslog_permissions() treats it as a boolean and also hardwires the knowledge that SYSLOG_FROM_PROC == 1 (or == `true`). And the name is wrong: it should be called from_proc to match SYSLOG_FROM_PROC." Signed-off-by: Vasily Averin Cc: Kees Cook Cc: Josh Boyer Cc: Eric Paris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/syslog.h | 6 +++--- kernel/printk/printk.c | 10 +++++----- 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/include/linux/syslog.h b/include/linux/syslog.h index 4b7b875a7ce1..c3a7f0cc3a27 100644 --- a/include/linux/syslog.h +++ b/include/linux/syslog.h @@ -47,12 +47,12 @@ #define SYSLOG_FROM_READER 0 #define SYSLOG_FROM_PROC 1 -int do_syslog(int type, char __user *buf, int count, bool from_file); +int do_syslog(int type, char __user *buf, int count, int source); #ifdef CONFIG_PRINTK -int check_syslog_permissions(int type, bool from_file); +int check_syslog_permissions(int type, int source); #else -static inline int check_syslog_permissions(int type, bool from_file) +static inline int check_syslog_permissions(int type, int source) { return 0; } diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 45fa8c88ac47..de553849f3ac 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -489,13 +489,13 @@ static int syslog_action_restricted(int type) type != SYSLOG_ACTION_SIZE_BUFFER; } -int check_syslog_permissions(int type, bool from_file) +int check_syslog_permissions(int type, int source) { /* * If this is from /proc/kmsg and we've already opened it, then we've * already done the capabilities checks at open time. */ - if (from_file && type != SYSLOG_ACTION_OPEN) + if (source == SYSLOG_FROM_PROC && type != SYSLOG_ACTION_OPEN) goto ok; if (syslog_action_restricted(type)) { @@ -1290,13 +1290,13 @@ static int syslog_print_all(char __user *buf, int size, bool clear) return len; } -int do_syslog(int type, char __user *buf, int len, bool from_file) +int do_syslog(int type, char __user *buf, int len, int source) { bool clear = false; static int saved_console_loglevel = LOGLEVEL_DEFAULT; int error; - error = check_syslog_permissions(type, from_file); + error = check_syslog_permissions(type, source); if (error) goto out; @@ -1379,7 +1379,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file) syslog_prev = 0; syslog_partial = 0; } - if (from_file) { + if (source == SYSLOG_FROM_PROC) { /* * Short-cut for poll(/"proc/kmsg") which simply checks * for pending data, not the size; return the count of -- GitLab