sysctl.conf: prevent autoloading of TTY line disciplines

[ipfire-2.x.git] / config / etc / sysctl.conf

diff --git a/config/etc/sysctl.conf b/config/etc/sysctl.conf
index 9a943fffa886430d4d45078f19f5b3dbc796bbb6..832ad3d1c23ffa8f05a233cf09b7c5485cf9e386 100644 (file)
--- a/config/etc/sysctl.conf
+++ b/config/etc/sysctl.conf
@@ -32,19 +32,32 @@ net.ipv6.conf.all.disable_ipv6 = 1
 net.ipv6.conf.default.disable_ipv6 = 1
 
 # Enable netfilter accounting
-net.netfilter.nf_conntrack_acct=1
+net.netfilter.nf_conntrack_acct = 1
 
 # Disable netfilter on bridges.
 net.bridge.bridge-nf-call-ip6tables = 0
 net.bridge.bridge-nf-call-iptables = 0
 net.bridge.bridge-nf-call-arptables = 0
 
+# Restrict loading TTY line disciplines to CAP_SYS_MODULE to prevent unprivileged attackers
+# from loading vulnerable line disciplines with the TIOCSETD ioctl.
+dev.tty.ldisc_autoload = 0
+
 # Try to keep kernel address exposures out of various /proc files (kallsyms, modules, etc).
 kernel.kptr_restrict = 2
 
 # Avoid kernel memory address exposures via dmesg.
 kernel.dmesg_restrict = 1
 
+# Turn on hard- and symlink protection
+fs.protected_symlinks = 1
+fs.protected_hardlinks = 1
+
+# Don't allow writes to files and FIFOs that we don't own in world writable sticky
+# directories, unless they are owned by the owner of the directory.
+fs.protected_fifos = 2
+fs.protected_regular = 2
+
 # Minimal preemption granularity for CPU-bound tasks:
 # (default: 1 msec#  (1 + ilog(ncpus)), units: nanoseconds)
 kernel.sched_min_granularity_ns = 10000000
@@ -76,9 +89,24 @@ vm.swappiness = 1
 kernel.sched_migration_cost_ns = 5000000
 
 # Increase kernel buffer size maximums
+net.ipv4.tcp_mem = 16777216 16777216 16777216
 net.ipv4.tcp_rmem = 4096 87380 16777216
 net.ipv4.tcp_wmem = 4096 16384 16777216
 net.ipv4.udp_mem = 3145728 4194304 16777216
 
+# Prefer low latency over higher throughput
+net.ipv4.tcp_low_latency = 1
+
+# Reserve more socket space for the TCP window
+net.ipv4.tcp_adv_win_scale = 2
+
 # Enable TCP fast-open
 net.ipv4.tcp_fastopen = 3
+
+# Drop RST packets for sockets in TIME-WAIT state, as described in RFC 1337.
+# This protects against various TCP attacks, such as DoS against or injection
+# of arbitrary segments into prematurely closed connections.
+net.ipv4.tcp_rfc1337 = 1
+
+# Include PID in file names of generated core dumps
+kernel.core_uses_pid = 1