Commit 7715dad8 authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

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: default avatarJeff Layton <jlayton@redhat.com>
Reviewed-by: default avatarPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: default avatarSteve French <smfrench@gmail.com>
parent 896a8fc2

fs/cifs/cifs_debug.c

+14 −6
Original line number Diff line number Diff line
@@ -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) {

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