Merge tag 'pstore-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/ke…

…rnel/git/kees/linux

Pull pstore update from Kees Cook:
 "Make pstore permissions more versatile by removing CAP_SYSLOG
  requirement and defining more restrictive root directory DAC
  permissions default (0750, which can be adjust after boot unlike the
  CAP_SYSLOG check).

  Suggested by Nick Kralevich"

* tag 'pstore-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Revert "pstore: Honor dmesg_restrict sysctl on dmesg dumps"
  pstore: Make default pstorefs root dir perms 0750

fs/pstore/inode.c

@@ -36,7 +36,6 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/uaccess.h>
-#include <linux/syslog.h>
 
 #include "internal.h"
 
@@ -132,18 +131,6 @@ static const struct seq_operations pstore_ftrace_seq_ops = {
 	.show	= pstore_ftrace_seq_show,
 };
 
-static int pstore_check_syslog_permissions(struct pstore_private *ps)
-{
-	switch (ps->record->type) {
-	case PSTORE_TYPE_DMESG:
-	case PSTORE_TYPE_CONSOLE:
-		return check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
-			SYSLOG_FROM_READER);
-	default:
-		return 0;
-	}
-}
-
 static ssize_t pstore_file_read(struct file *file, char __user *userbuf,
 						size_t count, loff_t *ppos)
 {
@@ -163,10 +150,6 @@ static int pstore_file_open(struct inode *inode, struct file *file)
 	int err;
 	const struct seq_operations *sops = NULL;
 
-	err = pstore_check_syslog_permissions(ps);
-	if (err)
-		return err;
-
 	if (ps->record->type == PSTORE_TYPE_FTRACE)
 		sops = &pstore_ftrace_seq_ops;
 
@@ -204,11 +187,6 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
 {
 	struct pstore_private *p = d_inode(dentry)->i_private;
 	struct pstore_record *record = p->record;
-	int err;
-
-	err = pstore_check_syslog_permissions(p);
-	if (err)
-		return err;
 
 	if (!record->psi->erase)
 		return -EPERM;
@@ -471,7 +449,7 @@ static int pstore_fill_super(struct super_block *sb, void *data, int silent)
 
 	inode = pstore_get_inode(sb);
 	if (inode) {
-		inode->i_mode = S_IFDIR | 0755;
+		inode->i_mode = S_IFDIR | 0750;
 		inode->i_op = &pstore_dir_inode_operations;
 		inode->i_fop = &simple_dir_operations;
 		inc_nlink(inode);

include/linux/syslog.h

@@ -49,13 +49,4 @@
 
 int do_syslog(int type, char __user *buf, int count, int source);
 
-#ifdef CONFIG_PRINTK
-int check_syslog_permissions(int type, int source);
-#else
-static inline int check_syslog_permissions(int type, int source)
-{
-	return 0;
-}
-#endif
-
 #endif /* _LINUX_SYSLOG_H */

kernel/printk/printk.c

@@ -649,7 +649,7 @@ static int syslog_action_restricted(int type)
 	       type != SYSLOG_ACTION_SIZE_BUFFER;
 }
 
-int check_syslog_permissions(int type, int source)
+static int check_syslog_permissions(int type, int source)
 {
 	/*
 	 * If this is from /proc/kmsg and we've already opened it, then we've
@@ -677,7 +677,6 @@ int check_syslog_permissions(int type, int source)
 ok:
 	return security_syslog(type);
 }
-EXPORT_SYMBOL_GPL(check_syslog_permissions);
 
 static void append_char(char **pp, char *e, char c)
 {