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>
This commit is contained in:
Jeff Layton 2013-05-26 07:01:01 -04:00 committed by Steve French
parent 896a8fc25b
commit 7715dad8e1

View File

@ -598,6 +598,7 @@ static int cifs_security_flags_proc_open(struct inode *inode, struct file *file)
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 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
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) {