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authorPaul Moore <paul@paul-moore.com>2020-04-20 16:24:34 -0400
committerPaul Moore <paul@paul-moore.com>2020-04-20 17:10:58 -0400
commit763dafc520add02a1f4639b500c509acc0ea8e5b (patch)
tree4cd7df4981685c473ae1ebd6f0a1df7e33ef03c9 /kernel/audit.c
parentae83d0b416db002fe95601e7f97f64b59514d936 (diff)
downloadlinux-763dafc520add02a1f4639b500c509acc0ea8e5b.tar.bz2
audit: check the length of userspace generated audit records
Commit 756125289285 ("audit: always check the netlink payload length in audit_receive_msg()") fixed a number of missing message length checks, but forgot to check the length of userspace generated audit records. The good news is that you need CAP_AUDIT_WRITE to submit userspace audit records, which is generally only given to trusted processes, so the impact should be limited. Cc: stable@vger.kernel.org Fixes: 756125289285 ("audit: always check the netlink payload length in audit_receive_msg()") Reported-by: syzbot+49e69b4d71a420ceda3e@syzkaller.appspotmail.com Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'kernel/audit.c')
-rw-r--r--kernel/audit.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index b69c8b460341..87f31bf1f0a0 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1326,6 +1326,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
if (!audit_enabled && msg_type != AUDIT_USER_AVC)
return 0;
+ /* exit early if there isn't at least one character to print */
+ if (data_len < 2)
+ return -EINVAL;
err = audit_filter(msg_type, AUDIT_FILTER_USER);
if (err == 1) { /* match or error */