From: Dan Carpenter dan.carpenter@oracle.com
[ 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: f7112e6c9abf ("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 --- security/smack/smackfs.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 840a192e93370..2bae1fc493d16 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -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;