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| author | Paul Moore <paul@paul-moore.com> | 2020-04-20 22:24:34 +0200 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2020-04-20 23:10:58 +0200 |
| commit | 763dafc520add02a1f4639b500c509acc0ea8e5b (patch) | |
| tree | 4cd7df4981685c473ae1ebd6f0a1df7e33ef03c9 /kernel/audit.c | |
| parent | Linux 5.7-rc2 (diff) | |
| download | linux-763dafc520add02a1f4639b500c509acc0ea8e5b.tar.xz linux-763dafc520add02a1f4639b500c509acc0ea8e5b.zip | |
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.c | 3 |
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 */ |