Reported in bug 1238 is an issue where stream reassembly can be
disrupted.
A packet that was in-window, but otherwise unexpected set the
window to a really low value, causing the next *expected* packet
to be considered out of window. This lead to missing data in the
stream reassembly.
The packet was unexpected in various ways:
- it would ack unseen traffic
- it's sequence number would not match the expected next_seq
- set a really low window, while not being a proper window update
Detection however, it greatly hampered by the fact that in case of
packet loss, quite similar packets come in. Alerting in this case
is unwanted. Ignoring/skipping packets in this case as well.
The logic used in this patch is as follows. If:
- the packet is not a window update AND
- packet seq > next_seq AND
- packet acq > next_seq (packet acks unseen data) AND
- packet shrinks window more than it's own data size
THEN set event and skip the packet in the stream engine.
So in case of a segment with no data, any window shrinking is rejected.
Bug #1238.
Until now the time out handling in defrag was done using a single
uint32_t that tracked seconds. This lead to corner cases, where
defrag trackers could be timed out a little too early.
If a next header / protocol is encountered that we can't handle (yet)
set an event. Disabled the rule by default.
decode-event:ipv6.unknown_next_header;
Fix or rather implement handling of unfragmentable exthdrs in ipv6.
The exthdr(s) appearing before the frag header were copied into the
reassembled packet correctly, however the stripping of the frag header
did not work correctly.
Example:
The common case is a frag header directly after the ipv6 header:
[ipv6 header]->[frag header]->[icmpv6 (part1)]
[ipv6 header]->[frag header]->[icmpv6 (part2)]
This would result in:
[ipv6 header]->[icmpv6]
The ipv6 headers 'next header' setting would be updated to point to
whatever the frag header was pointing to.
This would also happen when is this case:
[ipv6 header]->[hop header]->[frag header]->[icmpv6 (part1)]
[ipv6 header]->[hop header]->[frag header]->[icmpv6 (part2)]
The result would be:
[ipv6 header]->[hop header]->[icmpv6]
However, here too the ipv6 header would have been updated to point
to what the frag header pointed at. So it would consider the hop header
as if it was an ICMPv6 header, or whatever the frag header pointed at.
The result is that packets would not be correctly parsed, and thus this
issue can lead to evasion.
This patch implements handling of the unfragmentable part. In the first
segment that is stored in the list for reassembly, this patch detects
unfragmentable headers and updates it to have the last unfragmentable
header point to the layer after the frag header.
Also, the ipv6 headers 'next hdr' is only updated if no unfragmentable
headers are used. If they are used, the original value is correct.
Reported-By: Rafael Schaefer <rschaefer@ernw.de>
Bug #1244.
coccinelle 1.0rc21 has a problem with regular expression handling.
This result in a Fatal Error when test system detects an coding
error.
This patch fixes the problem by using a simple blob inside
semantic patch instead of using a regular expression to define
the function.
It also fixes add an optimization on matching suppressing a
useless <.. ..> construction.
Fixes have been suggested by Julia Lawall.
AC_TRY_COMPILE puts the code in a function already, and Clang didn't like
the function within the function declaration. This lead to test failure.
Clang now properly detects __thread support.
When the config is missing, DefragPolicyGetHostTimeout will default
to returning -1. This will effectively set no timeout at all, leading
to defrag trackers being freed too early.
This patch is fixing an issue in defragmentation code. The
insertion of a fragment in the list of fragments is done with
respect to the offset of the fragment. But the code was using
the original offset of the fragment and not the one of the
new reconstructed fragment (which can be different in the
case of overlapping segment where the left part is trimmed).
This case could lead to some evasion techniques by causing
Suricata to analyse a different payload.
This patch fixes the following issue reported by valgrind:
31 errors in context 1 of 1:
Conditional jump or move depends on uninitialised value(s)
at 0x8AB2F8: UnixSocketPcapFilesCheck (runmode-unix-socket.c:279)
by 0x97725D: UnixCommandBackgroundTasks (unix-manager.c:368)
by 0x97BC52: UnixManagerThread (unix-manager.c:884)
by 0x6155F6D: start_thread (pthread_create.c:311)
by 0x6E3A9CC: clone (clone.S:113)
The running field in PcapCommand was not initialized.
This patch fixes an issue in unix socket handling. It is possible
that a socket did disconnect when analysing a command and because
the data treatment is done in a loop on clients this was leading
to a update of the list of clients during the loop. So we need
in fact to use TAILQ_FOREACH_SAFE instead of TAILQ_FOREACH.
Reported-by: Luigi Sandon <luigi.sandon@gmail.com>
Fix-suggested-by: Luigi Sandon <luigi.sandon@gmail.com>
It is possible to have a non-contiguous CPU set, which was not being
handled correctly on the TILE architecture.
Added a "rank" field in the ThreadVar to store the worker's rank separately
from the cpu for this case.
When applying wildcard thresholds (with sid = 0 and/or gid = 0) it's wrong
to exit on the first signature already having an event filter. Indeed,
doing so results in the theshold not being applied to all subsequent
signatures. Change the code in order to skip signatures with event
filters instead of breaking out of the loop.
If a live reload signal was given before the engine was fully started
up (e.g. pcap file thread waiting for a disk to spin up), a segv could
occur.
This patch only enables live reloads after the threads have been
started up completely.
Victor Julien
Eric Leblond
sxhlinux
Alexander Gozman
sxhlinux
Ken Steele
Mats Klepsland
Alessandro Guido
Giuseppe Longo
Jason Ish