cifs: clean up the SecurityFlags write handler
The SecurityFlags handler uses an obsolete simple_strtoul() call, and
doesn't really handle the bounds checking well. Fix it to use
kstrtouint() instead. Clean up the error messages as well and fix a
bogus check for an unsigned int to be less than 0.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index d597483..856f8f5 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -598,6 +598,7 @@
static ssize_t cifs_security_flags_proc_write(struct file *file,
const char __user *buffer, size_t count, loff_t *ppos)
{
+ int rc;
unsigned int flags;
char flags_string[12];
char c;
@@ -620,26 +621,33 @@
global_secflags = CIFSSEC_MAX;
return count;
} else if (!isdigit(c)) {
- cifs_dbg(VFS, "invalid flag %c\n", c);
+ cifs_dbg(VFS, "Invalid SecurityFlags: %s\n",
+ flags_string);
return -EINVAL;
}
}
- /* else we have a number */
- flags = simple_strtoul(flags_string, NULL, 0);
+ /* else we have a number */
+ rc = kstrtouint(flags_string, 0, &flags);
+ if (rc) {
+ cifs_dbg(VFS, "Invalid SecurityFlags: %s\n",
+ flags_string);
+ return rc;
+ }
cifs_dbg(FYI, "sec flags 0x%x\n", flags);
- if (flags <= 0) {
- cifs_dbg(VFS, "invalid security flags %s\n", flags_string);
+ if (flags == 0) {
+ cifs_dbg(VFS, "Invalid SecurityFlags: %s\n", flags_string);
return -EINVAL;
}
if (flags & ~CIFSSEC_MASK) {
- cifs_dbg(VFS, "attempt to set unsupported security flags 0x%x\n",
+ cifs_dbg(VFS, "Unsupported security flags: 0x%x\n",
flags & ~CIFSSEC_MASK);
return -EINVAL;
}
+
/* flags look ok - update the global security flags for cifs module */
global_secflags = flags;
if (global_secflags & CIFSSEC_MUST_SIGN) {