diff options
| author | Eric Dumazet <edumazet@google.com> | 2019-05-18 05:12:05 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-06-15 18:47:31 -0700 |
| commit | f070ef2ac66716357066b683fb0baf55f8191a2e (patch) | |
| tree | 1ae8c5a4c6c989a13cf77c4e1d09754756f1cc2c /include/uapi | |
| parent | 3b4929f65b0d8249f19a50245cd88ed1a2f78cff (diff) | |
tcp: tcp_fragment() should apply sane memory limits
Jonathan Looney reported that a malicious peer can force a sender
to fragment its retransmit queue into tiny skbs, inflating memory
usage and/or overflow 32bit counters.
TCP allows an application to queue up to sk_sndbuf bytes,
so we need to give some allowance for non malicious splitting
of retransmit queue.
A new SNMP counter is added to monitor how many times TCP
did not allow to split an skb if the allowance was exceeded.
Note that this counter might increase in the case applications
use SO_SNDBUF socket option to lower sk_sndbuf.
CVE-2019-11478 : tcp_fragment, prevent fragmenting a packet when the
socket is already using more than half the allowed space
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/snmp.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h index 86dc24a96c90..fd42c1316d3d 100644 --- a/include/uapi/linux/snmp.h +++ b/include/uapi/linux/snmp.h @@ -283,6 +283,7 @@ enum LINUX_MIB_TCPACKCOMPRESSED, /* TCPAckCompressed */ LINUX_MIB_TCPZEROWINDOWDROP, /* TCPZeroWindowDrop */ LINUX_MIB_TCPRCVQDROP, /* TCPRcvQDrop */ + LINUX_MIB_TCPWQUEUETOOBIG, /* TCPWqueueTooBig */ __LINUX_MIB_MAX }; |