Commit 67499265 authored Jul 23, 2020 by Dan Carpenter Committed by Greg Kroah-Hartman Aug 19, 2020

Smack: fix another vsscanf out of bounds



[ Upstream commit a6bd4f6d9b07452b0b19842044a6c3ea384b0b88 ]

This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in
vsscanf") where we added a bounds check on "rule".

Reported-by:  <syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com>
Fixes: f7112e6c ("Smack: allow for significantly longer Smack labels v4")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 3a2cd06a

security/smack/smackfs.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -905,6 +905,10 @@ static ssize_t smk_set_cipso(struct file file, const char __user buf,

		for (i = 0; i < catlen; i++) {
		rule += SMK_DIGITLEN;
		if (rule > data + count) {
		rc = -EOVERFLOW;
		goto out;
		}
		ret = sscanf(rule, "%u", &cat);
		if (ret != 1 \|\| cat > SMACK_CIPSO_MAXCATNUM)
		goto out;