kernel_optimize_test/drivers
Hannes Frederic Sowa f3d3342602 net: rework recvmsg handler msg_name and msg_namelen logic
This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-20 21:52:30 -05:00
..
accessibility
acpi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
amba
ata
atm atm: idt77252: fix dev refcnt leak 2013-11-19 15:53:02 -05:00
auxdisplay
base
bcma
block
bluetooth
bus
cdrom
char
clk
clocksource
connector
cpufreq
cpuidle
crypto
dca
devfreq
dio
dma
edac
eisa
extcon
firewire
firmware
fmc
gpio
gpu Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2013-11-18 15:50:07 -08:00
hid
hsi
hv
hwmon
hwspinlock
i2c Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2013-11-18 15:50:07 -08:00
ide
idle
iio
infiniband Main batch of InfiniBand/RDMA changes for 3.13: 2013-11-18 15:36:04 -08:00
input
iommu
ipack
irqchip
isdn net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
leds
lguest
macintosh
mailbox
md
media Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2013-11-18 15:50:07 -08:00
memory
memstick
message
mfd
misc Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2013-11-18 15:50:07 -08:00
mmc
mtd
net net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
nfc
ntb
nubus
of
oprofile
parisc
parport
pci
pcmcia
phy
pinctrl
platform
pnp
power
powercap
pps
ps3
ptp
pwm
rapidio
regulator
remoteproc
reset
rpmsg
rtc
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2013-11-19 11:43:21 -08:00
sbus
scsi aacraid: prevent invalid pointer dereference 2013-11-19 16:27:39 -08:00
sfi
sh
sn
spi
ssb
staging
target
tc
thermal Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
tty
uio
usb
uwb
vfio
vhost
video
virt
virtio
vlynq
vme
w1
watchdog
xen
zorro
Kconfig
Makefile