Eric Dumazet 7f9f8a37e5 tcp: add tcp_min_snd_mss sysctl ... commit 5f3e2bf008 upstream. Some TCP peers announce a very small MSS option in their SYN and/or SYN/ACK messages. This forces the stack to send packets with a very high network/cpu overhead. Linux has enforced a minimal value of 48. Since this value includes the size of TCP options, and that the options can consume up to 40 bytes, this means that each segment can include only 8 bytes of payload. In some cases, it can be useful to increase the minimal value to a saner value. We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility reasons. Note that TCP_MAXSEG socket option enforces a minimal value of (TCP_MIN_MSS). David Miller increased this minimal value in commit c39508d6f1 ("tcp: Make TCP_MAXSEG minimum more correct.") from 64 to 88. We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS. CVE-2019-11479 -- tcp mss hardcoded to 48 Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Jonathan Looney <jtl@netflix.com> Acked-by: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2019-06-17 19:51:56 +02:00
..
ABI	Documentation: Add MDS vulnerability documentation	2019-05-14 19:17:58 +02:00
accelerators	ocxl: Document new OCXL IOCTLs	2018-06-03 20:40:33 +10:00
accounting
acpi	ACPI: property: graph: Update graph documentation to use generic references	2018-07-23 12:44:52 +02:00
admin-guide	Documentation: Correct the possible MDS sysfs values	2019-05-14 19:18:00 +02:00
aoe
arm	ARM: 8833/1: Ensure that NEON code always compiles with Clang	2019-04-05 22:33:08 +02:00
arm64	arm64: errata: Add workaround for Cortex-A76 erratum #1463225	2019-05-31 06:46:03 -07:00
auxdisplay	Doc: misc-devices: move lcd-panel-cgram.txt to auxdisplay/	2018-04-12 16:08:02 +02:00
backlight
block	block: Track DISCARD statistics and output them in stat and diskstat	2018-07-18 08:44:22 -06:00
blockdev	zram: introduce zram memory tracking	2018-06-07 17:34:34 -07:00
bpf	Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next	2018-08-07 11:02:05 -07:00
bus-devices
cdrom
cgroup-v1	page cache: use xa_lock	2018-04-11 10:28:39 -07:00
cma
connector
console	Documentation: corrections to console/console.txt	2018-08-10 16:09:40 -06:00
core-api	idr: Change documentation license	2018-10-15 16:31:29 -04:00
cpu-freq
cpuidle
crypto	crypto: remove redundant type flags from tfm allocation	2018-07-09 00:30:29 +08:00
dev-tools	doc: dev-tools: kselftest.rst: update contributing new tests	2018-06-29 09:01:50 -06:00
device-mapper	dm raid: bump target version, update comments and documentation	2018-09-06 17:07:58 -04:00
devicetree	dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string	2019-02-20 10:25:35 +01:00
doc-guide	Documentation/sphinx: allow "functions" with no parameters	2018-06-30 07:52:42 -06:00
driver-api	USB: core: Fix bug caused by duplicate interface PM usage counter	2019-05-08 07:21:44 +02:00
driver-model	dmaengine: add a new helper dmaenginem_async_device_register	2018-07-30 10:50:22 +05:30
early-userspace	initramfs: move gen_initramfs_list.sh from scripts/ to usr/	2018-08-22 23:21:44 +09:00
EDID
extcon
fault-injection
fb	uvesafb: Fix URLs in the documentation	2018-09-26 18:11:23 +02:00
features	ARM: 8777/1: Hook up SYNC_CORE functionality for sys_membarrier()	2018-07-11 11:02:08 +01:00
filesystems	dcache: sort the freeing-without-RCU-delay mess for good.	2019-05-25 18:23:26 +02:00
firmware_class
fmc
fpga	docs: fpga: add a document for FPGA Device Feature List (DFL) Framework Overview	2018-07-15 13:55:44 +02:00
gpio
gpu	drm/msm/gpu: Add the buffer objects from the submit to the crash dump	2018-07-30 08:50:10 -04:00
hid
hwmon	hwmon: (ina2xx) fix sysfs shunt resistor read access	2018-08-26 17:45:25 -07:00
i2c	i2c: i801: Add support for Intel Comet Lake	2019-05-04 09:20:15 +02:00
ia64
ide
iio
infiniband
input	input: add MT_TOOL_DIAL	2018-07-17 15:33:47 +02:00
ioctl	Char/Misc driver patches for 4.19-rc1	2018-08-18 11:04:51 -07:00
isdn
kbuild	kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt	2018-08-22 23:21:42 +09:00
kdump
kernel-hacking	doc:it_IT: translation for kernel-hacking	2018-07-26 16:21:09 -06:00
laptops	platform/x86: thinkpad_acpi: silence HKEY 0x6032, 0x60f0, 0x6030	2018-05-07 15:10:31 +03:00
leds
lightnvm
livepatch	livepatch: Remove not longer valid limitations from the documentation	2018-05-24 15:37:57 +02:00
locking	locking: Implement an algorithm choice for Wound-Wait mutexes	2018-07-03 09:44:36 +02:00
m68k
maintainer	docs: Fix more broken references	2018-06-15 18:11:26 -03:00
md
media	media: replace ADOBERGB by OPRGB	2018-11-13 11:08:54 -08:00
memory-devices
mic
mips
misc-devices	pci_endpoint_test: Add 2 ioctl commands	2018-07-19 11:46:57 +01:00
mmc
mtd
namespaces
netlabel
networking	tcp: add tcp_min_snd_mss sysctl	2019-06-17 19:51:56 +02:00
nfc
nios2
nvdimm
nvmem
openrisc
parisc
PCI	Merge branch 'remotes/lorenzo/pci/dwc'	2018-08-15 14:59:11 -05:00
pcmcia	pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function	2018-08-18 12:30:42 -07:00
perf
phy
platform
power	PM / reboot: Eliminate race between reboot and suspend	2018-08-06 12:35:20 +02:00
powerpc	powerpc: Document issues with TM on POWER9	2018-07-02 23:54:29 +10:00
pps
process	stable-kernel-rules.rst: add link to networking patch queue	2019-03-23 20:10:10 +01:00
pti
ptp
rapidio
RCU	rculist: Improve documentation for list_for_each_entry_from_rcu()	2018-07-12 15:39:25 -07:00
riscv	perf: riscv: Add Document for Future Porting Guide	2018-06-04 14:02:11 -07:00
s390
scheduler	sched/deadline/Documentation: Add overrun signal and GRUB-PA documentation	2018-05-14 09:12:27 +02:00
scsi	scsi: documentation: add scsi_mod.use_blk_mq to scsi-parameters	2018-08-27 12:26:10 -04:00
security	Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables	2018-06-14 12:21:18 +09:00
serial
sh
sound	ASoC: Updates for v4.19	2018-08-13 12:12:31 +02:00
sparc
sphinx	doc: Cope with Sphinx logging deprecations	2019-06-09 09:17:21 +02:00
sphinx-static
spi
sysctl	bpf: add bpf_jit_limit knob to restrict unpriv allocations	2019-05-31 06:46:03 -07:00
target
thermal
timers	timekeeping.txt: Correct maxCount of n-bit binary counter	2018-07-23 09:33:06 -06:00
trace	This was a moderately busy cycle for docs, with the usual collection of	2018-08-14 14:29:31 -07:00
translations	This was a moderately busy cycle for docs, with the usual collection of	2018-08-14 14:29:31 -07:00
usb	USB-serial updates for v4.19-rc1	2018-07-20 21:47:15 +02:00
userspace-api	x86/speculation: Add prctl() control for indirect branch speculation	2018-12-05 19:32:04 +01:00
virtual	KVM: Reject device ioctls from processes other than the VM's creator	2019-04-03 06:26:29 +02:00
vm	docs/vm: move ksm and transhuge from "user" to "internals" section.	2018-05-29 06:45:55 -06:00
w1	w1: fix w1_ds2438 documentation	2018-07-07 17:27:13 +02:00
watchdog
wimax
x86	x86/speculation/mds: Improve CPU buffer clear documentation	2019-05-22 07:37:35 +02:00
xtensa
.gitignore
00-INDEX	docs: admin-guide: add cgroup-v2 documentation	2018-05-10 15:42:41 -06:00
atomic_bitops.txt
atomic_t.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
Changes
clearing-warn-once.txt
CodingStyle
conf.py	docs: Fix conf.py for Sphinx 2.0	2019-06-09 09:17:20 +02:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt	Documentation: remove stale firmware API reference	2018-05-14 16:44:41 +02:00
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff
efi-stub.txt
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst	x86/speculation/mds: Add mds_clear_cpu_buffers()	2019-05-14 19:17:54 +02:00
Intel-IOMMU.txt
intel_txt.txt
io-mapping.txt
io_ordering.txt
iostats.txt	block: Track DISCARD statistics and output them in stat and diskstat	2018-07-18 08:44:22 -06:00
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-per-CPU-kthreads.txt
kobject.txt
kprobes.txt	kprobes/Documentation: Fix various typos	2018-06-22 11:10:55 +02:00
kref.txt
ldm.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lsm.txt
lzo.txt
mailbox.txt
Makefile
memory-barriers.txt	sched/Documentation: Update wake_up() & co. memory-barrier guarantees	2018-07-17 09:30:34 +02:00
memory-hotplug.txt
men-chameleon-bus.txt
nommu-mmap.txt	Documentation: nommu-map: Fix duplicate word typo	2018-06-26 09:01:27 -06:00
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt
pnp.txt
preempt-locking.txt
pwm.txt
rbtree.txt
remoteproc.txt
rfkill.txt	rfkill: Fix several typos in documentation	2018-06-15 13:36:08 +02:00
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt
static-keys.txt
SubmittingPatches
svga.txt
switchtec.txt
sync_file.txt
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
vfio-mediated-device.txt	vfio/mdev: Check globally for duplicate devices	2018-06-08 10:24:27 -06:00
vfio.txt	vfio: fix documentation	2018-05-08 09:16:41 -06:00
video-output.txt
xillybus.txt
xz.txt
zorro.txt