Add SA-15:13.tcp.
This commit is contained in:
Xin LI
parent
65f9164dd7
commit
838fb2801b
Notes:
svn2git
2020-12-08 03:00:23 +00:00
svn path=/head/; revision=47036
6 changed files with 269 additions and 0 deletions
165
share/security/advisories/FreeBSD-SA-15:13.tcp.asc
Normal file
165
share/security/advisories/FreeBSD-SA-15:13.tcp.asc
Normal file
|
|
@ -0,0 +1,165 @@
|
|||
-----BEGIN PGP SIGNED MESSAGE-----
|
||||
Hash: SHA512
|
||||
|
||||
=============================================================================
|
||||
FreeBSD-SA-15:13.tcp Security Advisory
|
||||
The FreeBSD Project
|
||||
|
||||
Topic: Resource exhaustion due to sessions stuck in LAST_ACK state
|
||||
|
||||
Category: core
|
||||
Module: inet
|
||||
Announced: 2015-07-21
|
||||
Credits: Lawrence Stewart (Netflix, Inc.),
|
||||
Jonathan Looney (Juniper SIRT)
|
||||
Affects: All supported versions of FreeBSD.
|
||||
Corrected: 2015-07-21 23:42:17 UTC (stable/10, 10.2-PRERELEASE)
|
||||
2015-07-21 23:42:17 UTC (stable/10, 10.2-BETA1-p1)
|
||||
2015-07-21 23:42:17 UTC (stable/10, 10.2-BETA2-p1)
|
||||
2015-07-21 23:42:56 UTC (releng/10.1, 10.1-RELEASE-p15)
|
||||
2015-07-21 23:42:20 UTC (stable/9, 9.3-STABLE)
|
||||
2015-07-21 23:42:56 UTC (releng/9.3, 9.3-RELEASE-p20)
|
||||
2015-07-21 23:42:20 UTC (stable/8, 8.4-STABLE)
|
||||
2015-07-21 23:42:56 UTC (releng/8.4, 8.4-RELEASE-p34)
|
||||
CVE Name: CVE-2015-5358
|
||||
|
||||
For general information regarding FreeBSD Security Advisories,
|
||||
including descriptions of the fields above, security branches, and the
|
||||
following sections, please visit <URL:https://security.FreeBSD.org/>.
|
||||
|
||||
I. Background
|
||||
|
||||
The Transmission Control Protocol (TCP) of the TCP/IP protocol suite
|
||||
provides a connection-oriented, reliable, sequence-preserving data
|
||||
stream service.
|
||||
|
||||
A socket enters the LAST_ACK state when the local process closes its socket
|
||||
after a FIN has already been received from the remote peer. The socket
|
||||
will remain in the LAST_ACK state until the kernel has transmitted a FIN to
|
||||
the remote peer and the kernel has received an acknowledgement of that FIN
|
||||
from the remote peer, or all retransmits of the FIN have failed and the
|
||||
connection times out.
|
||||
|
||||
II. Problem Description
|
||||
|
||||
TCP connections transitioning to the LAST_ACK state can become permanently
|
||||
stuck due to mishandling of protocol state in certain situations, which in
|
||||
turn can lead to accumulated consumption and eventual exhaustion of system
|
||||
resources, such as mbufs and sockets.
|
||||
|
||||
III. Impact
|
||||
|
||||
An attacker who can repeatedly establish TCP connections to a victim system
|
||||
(for instance, a Web server) could create many TCP connections that are
|
||||
stuck in LAST_ACK state and cause resource exhaustion, resulting in a
|
||||
denial of service condition. This may also happen in normal operation
|
||||
where no intentional attack is conducted, but an attacker who can send
|
||||
specifically crafted packets can trigger this more reliably.
|
||||
|
||||
IV. Workaround
|
||||
|
||||
No workaround is available, but systems that do not provide TCP based
|
||||
service to untrusted networks are not vulnerable.
|
||||
|
||||
Note that the tcpdrop(8) utility can be used to purge connections which
|
||||
have become wedged. For example, the following command can be used to
|
||||
generate commands that would drop all connections whose last rcvtime is
|
||||
more than 100s:
|
||||
|
||||
netstat -nxp tcp | \
|
||||
awk '{ if (int($NF) > 100) print "tcpdrop " $4 " " $5 }'
|
||||
|
||||
The system administrator can then run the generated script as a temporary
|
||||
measure. Please refer to the tcpdump(8) manual page for additional
|
||||
information.
|
||||
|
||||
V. Solution
|
||||
|
||||
Perform one of the following:
|
||||
|
||||
1) Upgrade your vulnerable system to a supported FreeBSD stable or
|
||||
release / security branch (releng) dated after the correction date.
|
||||
|
||||
2) To update your vulnerable system via a binary patch:
|
||||
|
||||
Systems running a RELEASE version of FreeBSD on the i386 or amd64
|
||||
platforms can be updated via the freebsd-update(8) utility:
|
||||
|
||||
# freebsd-update fetch
|
||||
# freebsd-update install
|
||||
|
||||
3) To update your vulnerable system via a source code patch:
|
||||
|
||||
The following patches have been verified to apply to the applicable
|
||||
FreeBSD release branches.
|
||||
|
||||
a) Download the relevant patch from the location below, and verify the
|
||||
detached PGP signature using your PGP utility.
|
||||
|
||||
[FreeBSD 10.1]
|
||||
# fetch https://security.FreeBSD.org/patches/SA-15:13/tcp.patch
|
||||
# fetch https://security.FreeBSD.org/patches/SA-15:13/tcp.patch.asc
|
||||
# gpg --verify tcp.patch.asc
|
||||
|
||||
[FreeBSD 9.x and 8.x]
|
||||
# fetch https://security.FreeBSD.org/patches/SA-15:13/tcp-9.patch
|
||||
# fetch https://security.FreeBSD.org/patches/SA-15:13/tcp-9.patch.asc
|
||||
# gpg --verify tcp-9.patch.asc
|
||||
|
||||
b) Apply the patch. Execute the following commands as root:
|
||||
|
||||
# cd /usr/src
|
||||
# patch < /path/to/patch
|
||||
|
||||
c) Recompile your kernel as described in
|
||||
<URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
|
||||
system.
|
||||
|
||||
VI. Correction details
|
||||
|
||||
The following list contains the correction revision numbers for each
|
||||
affected branch.
|
||||
|
||||
Branch/path Revision
|
||||
- -------------------------------------------------------------------------
|
||||
stable/8/ r285779
|
||||
releng/8.4/ r285780
|
||||
stable/9/ r285779
|
||||
releng/9.3/ r285780
|
||||
stable/10/ r285778
|
||||
releng/10.1/ r285780
|
||||
- -------------------------------------------------------------------------
|
||||
|
||||
To see which files were modified by a particular revision, run the
|
||||
following command, replacing NNNNNN with the revision number, on a
|
||||
machine with Subversion installed:
|
||||
|
||||
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
|
||||
|
||||
Or visit the following URL, replacing NNNNNN with the revision number:
|
||||
|
||||
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>
|
||||
|
||||
VII. References
|
||||
|
||||
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-5358>
|
||||
|
||||
The latest revision of this advisory is available at
|
||||
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-15:13.tcp.asc>
|
||||
-----BEGIN PGP SIGNATURE-----
|
||||
Version: GnuPG v2.1.6 (FreeBSD)
|
||||
|
||||
iQIcBAEBCgAGBQJVrtnrAAoJEO1n7NZdz2rnchoQAMUV9fuXsBvQgvugFVpoe4HP
|
||||
t7tTIzKKmvC3SVOQfPF6jQllVL9qbRJK9zVdFcGX0Iy07/QPKMIRIFXqiYmRwyXt
|
||||
YEuZtZMHEo6w5YS/gEwSndGRFduFAfhaNZndycjA3O5nxR16cvqScDUAv0nErQGD
|
||||
jJzhjbwdrT4fLg06PgLOdNwQKOPhdM1k4ZOdg7WUYDi2iQUmYpD2SOzRAx/SoDK7
|
||||
N0qd7Cy7mZBLbmm1zbCGDPhvNVYCKQjPjhiZ1GhfzUQ2n9bBOGLf2K1d/N0cttFH
|
||||
/MfJoi2yRlU3iJE2DOJeD0/m4sJLmTL/7sqYEP9W2939oVH0Bku/KoJG4I4rZLDl
|
||||
6yoKTxtyJGxbw8N2M/ObFpCQwn56Vjf2oo1LhIdBb+T48OwSwxuwrtw4VnlUnVLo
|
||||
oJ5UA1VnazoyU6AwADpHkGPEPvRF1SUXfOuIOoHiZZ6O3eHdoeD3e2HqLQhoYVCj
|
||||
PMEi/k45jPnWWhwV76I65Ig02YRgzhMTSunjXLQhi44Eeavf1SxHTJpSHuVjg3zu
|
||||
MDDW55yB+wJvoetwCg3IkFPfmFBmto679xywDCKVd9VYeKoFsiVE4F/APqf6hN7o
|
||||
qO8etL5oXnwjNsm9Tf8vImoWrBw2gRYkSieG+Vsx4r2r5JNHKRg1AVmRdihI1ATb
|
||||
canMZYhLMD6A1x5T54Ya
|
||||
=UPeI
|
||||
-----END PGP SIGNATURE-----
|
||||
31
share/security/patches/SA-15:13/tcp-9.patch
Normal file
31
share/security/patches/SA-15:13/tcp-9.patch
Normal file
|
|
@ -0,0 +1,31 @@
|
|||
Index: sys/netinet/tcp_output.c
|
||||
===================================================================
|
||||
--- sys/netinet/tcp_output.c (revision 285435)
|
||||
+++ sys/netinet/tcp_output.c (working copy)
|
||||
@@ -397,7 +397,7 @@ after_sack_rexmit:
|
||||
flags &= ~TH_FIN;
|
||||
}
|
||||
|
||||
- if (len < 0) {
|
||||
+ if (len <= 0) {
|
||||
/*
|
||||
* If FIN has been sent but not acked,
|
||||
* but we haven't been called to retransmit,
|
||||
@@ -407,9 +407,16 @@ after_sack_rexmit:
|
||||
* to (closed) window, and set the persist timer
|
||||
* if it isn't already going. If the window didn't
|
||||
* close completely, just wait for an ACK.
|
||||
+ *
|
||||
+ * We also do a general check here to ensure that
|
||||
+ * we will set the persist timer when we have data
|
||||
+ * to send, but a 0-byte window. This makes sure
|
||||
+ * the persist timer is set even if the packet
|
||||
+ * hits one of the "goto send" lines below.
|
||||
*/
|
||||
len = 0;
|
||||
- if (sendwin == 0) {
|
||||
+ if ((sendwin == 0) && (TCPS_HAVEESTABLISHED(tp->t_state)) &&
|
||||
+ (off < (int) so->so_snd.sb_cc)) {
|
||||
tcp_timer_activate(tp, TT_REXMT, 0);
|
||||
tp->t_rxtshift = 0;
|
||||
tp->snd_nxt = tp->snd_una;
|
||||
17
share/security/patches/SA-15:13/tcp-9.patch.asc
Normal file
17
share/security/patches/SA-15:13/tcp-9.patch.asc
Normal file
|
|
@ -0,0 +1,17 @@
|
|||
-----BEGIN PGP SIGNATURE-----
|
||||
Version: GnuPG v2.1.6 (FreeBSD)
|
||||
|
||||
iQIcBAABCgAGBQJVrtn5AAoJEO1n7NZdz2rnZNAP/isVEBX+KzcSl9/mQffRZXz2
|
||||
+dujbMeZn0eVBF2e8y+DaWWkaBPTjwKZBfAuaM+VAKaQ/Gb4wM5d5vaDlPS1c+qw
|
||||
ZsFDs7glL+szJY7OdodBRGnkAP4+aXcJhd5pLjqBQ37ZwaahpYXR6VD40WBrk9Xg
|
||||
b3IhftGkhkjCJhEeZ9ct/K8CqN31XSRwD2SX7aHkLODLEC5kOIoV5cxv5F4BgN+B
|
||||
gSbryW6ZcxExP0KABTthHamF24G9n1GTeEAZuGXJvOjJBu3co8XCHQp5ELbuP/lN
|
||||
UVeTwiyEgq7XiacwfLPCSKTfhEvymq3PlJHMzXq3AiTwbvP3xGaCoxxOMI/SUsBh
|
||||
JNs0Fi3ZfiPn8WAJTnf0E/xqEq6qkLTjMOYX9vXDC1HQElwCPv4SpMJ0pkvP7Hl4
|
||||
68EV+Ohrp4jGOYtUol7JardMHtnUUd4rs3TkutKcgy7I49/4FKQ8UFyf13DCxA01
|
||||
X0oxTdYoY9HwoRdIkJj+mcKiAFXAfrwoDWaZj6L6dZwXWg12N3c5f1i6vokczmaq
|
||||
lK28ui8u4LtUgfoU+FfXzwPT5zfQXG5JGr4ehwOCN1MvGJSbMMMmII3RgfrXAb/H
|
||||
/W+su8oCHCuHV2vRRClGKL80oVgt63LfHqUFY8QyQnmDqe+VOHsHiQQ5IGXHxJU3
|
||||
AiZDOe38k8NCOFahQtio
|
||||
=CFEV
|
||||
-----END PGP SIGNATURE-----
|
||||
31
share/security/patches/SA-15:13/tcp.patch
Normal file
31
share/security/patches/SA-15:13/tcp.patch
Normal file
|
|
@ -0,0 +1,31 @@
|
|||
Index: sys/netinet/tcp_output.c
|
||||
===================================================================
|
||||
--- sys/netinet/tcp_output.c (revision 285435)
|
||||
+++ sys/netinet/tcp_output.c (working copy)
|
||||
@@ -400,7 +400,7 @@ after_sack_rexmit:
|
||||
flags &= ~TH_FIN;
|
||||
}
|
||||
|
||||
- if (len < 0) {
|
||||
+ if (len <= 0) {
|
||||
/*
|
||||
* If FIN has been sent but not acked,
|
||||
* but we haven't been called to retransmit,
|
||||
@@ -410,9 +410,16 @@ after_sack_rexmit:
|
||||
* to (closed) window, and set the persist timer
|
||||
* if it isn't already going. If the window didn't
|
||||
* close completely, just wait for an ACK.
|
||||
+ *
|
||||
+ * We also do a general check here to ensure that
|
||||
+ * we will set the persist timer when we have data
|
||||
+ * to send, but a 0-byte window. This makes sure
|
||||
+ * the persist timer is set even if the packet
|
||||
+ * hits one of the "goto send" lines below.
|
||||
*/
|
||||
len = 0;
|
||||
- if (sendwin == 0) {
|
||||
+ if ((sendwin == 0) && (TCPS_HAVEESTABLISHED(tp->t_state)) &&
|
||||
+ (off < (int) so->so_snd.sb_cc)) {
|
||||
tcp_timer_activate(tp, TT_REXMT, 0);
|
||||
tp->t_rxtshift = 0;
|
||||
tp->snd_nxt = tp->snd_una;
|
||||
17
share/security/patches/SA-15:13/tcp.patch.asc
Normal file
17
share/security/patches/SA-15:13/tcp.patch.asc
Normal file
|
|
@ -0,0 +1,17 @@
|
|||
-----BEGIN PGP SIGNATURE-----
|
||||
Version: GnuPG v2.1.6 (FreeBSD)
|
||||
|
||||
iQIcBAABCgAGBQJVrtn8AAoJEO1n7NZdz2rnTxgP/RaL03Wk7bJDuusYOT5i/QYz
|
||||
t09p23Xf1dTayN/6CJQj9knt9Dp7CnX7Yjev/R+MEWOvEbYg4hP5iqpPRK4pIpAZ
|
||||
yfq6jO5w1Fis5GA8sYW6MEgQd9LOCeqTLHL/rJjiqwpMR0KwV82gNvKu4vwAfBqO
|
||||
sZZ3tNutRS0Kx22dt4rHXnZz08ldPvRF697XTJ858BSZcpqKVouUAM/7MrJ+HQCL
|
||||
51v4mLX5ewhuJ/Z1/sMPIfbQ4j1JceIG11xAeNkDwaC4MXkKrHkZK0PuLIBwyPKK
|
||||
nezCQ9UveoMSkVhelgkeb+QVTDwwiVBFCMBOD4acs7aswRNwNJO3faMmlf2oGFbG
|
||||
64tbIIH3AKKa7Q6Qd/agfoxFzSSdMGK0MuHauJOsiacPQqa5pO3wKoeFSobEQSQO
|
||||
XY2n+t763PpDdDmqjroqOcEemsN5cMbr8B3fil5e1sihN1df/Jkw4Ifz6s4R0SYI
|
||||
wo2mCurcygiUVoWuitNsPlDrPPh0EAwxcjmSOLgxsVukZKQRXgm3vx1zfyuyN3z/
|
||||
KZQERfspSRakM9nVuk7usJr2J4RwPJrEtYhu8hjlPVmZEAaQSCJYtmwj3LYiyUc0
|
||||
4Pq1tSqlfz5Oba13Q2W+09FuctLiobXhCftsYeodOfuofWLqQmi3B4A4nz3jBUI7
|
||||
zQj83z7/kojfqRNHhYNf
|
||||
=WBT+
|
||||
-----END PGP SIGNATURE-----
|
||||
|
|
@ -10,6 +10,14 @@
|
|||
<month>
|
||||
<name>7</name>
|
||||
|
||||
<day>
|
||||
<name>21</name>
|
||||
|
||||
<advisory>
|
||||
<name>FreeBSD-SA-15:13.tcp</name>
|
||||
</advisory>
|
||||
</day>
|
||||
|
||||
<day>
|
||||
<name>9</name>
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue