| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 082/267] Smack: slab-out-of-bounds in vsscanf | Date | Fri, 19 Jun 2020 16:31:07 +0200 |
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From: Casey Schaufler <casey@schaufler-ca.com>
commit 84e99e58e8d1e26f04c097f4266e431a33987f36 upstream.
Add barrier to soob. Return -EOVERFLOW if the buffer is exceeded.
Suggested-by: Hillf Danton <hdanton@sina.com> Reported-by: syzbot+bfdd4a2f07be52351350@syzkaller.appspotmail.com Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- security/smack/smackfs.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
--- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -906,11 +906,21 @@ static ssize_t smk_set_cipso(struct file 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;
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