From 61f8b8965c11df8f0eedce895f8eeb6eb7c1538f Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Thu, 9 Apr 2020 16:35:28 -0700 Subject: Smack: slab-out-of-bounds in vsscanf commit 84e99e58e8d1e26f04c097f4266e431a33987f36 upstream. Add barrier to soob. Return -EOVERFLOW if the buffer is exceeded. Suggested-by: Hillf Danton Reported-by: syzbot+bfdd4a2f07be52351350@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler Signed-off-by: Greg Kroah-Hartman --- security/smack/smackfs.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index f6482e53d55a..371ae368da35 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -906,11 +906,21 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf, else rule += strlen(skp->smk_known) + 1; + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + ret = sscanf(rule, "%d", &maplevel); if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL) goto out; rule += SMK_DIGITLEN; + if (rule > data + count) { + rc = -EOVERFLOW; + goto out; + } + ret = sscanf(rule, "%d", &catlen); if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM) goto out; -- cgit v1.2.3