linux-toradex.git/net/socket.c, branch v3.2.40

net: fix info leak in compat dev_ifconf()

2012-09-19T14:04:55+00:00

[ Upstream commit 43da5f2e0d0c69ded3d51907d9552310a6b545e8 ]

The implementation of dev_ifconf() for the compat ioctl interface uses
an intermediate ifc structure allocated in userland for the duration of
the syscall. Though, it fails to initialize the padding bytes inserted
for alignment and that for leaks four bytes of kernel stack. Add an
explicit memset(0) before filling the structure to avoid the info leak.

Signed-off-by: Mathias Krause 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: allow splice() to build full TSO packets

2012-05-11T12:14:17+00:00

[ This combines upstream commit
  2f53384424251c06038ae612e56231b96ab610ee and the follow-on bug fix
  commit 35f9c09fe9c72eb8ca2b8e89a593e1c151f28fc2 ]

vmsplice()/splice(pipe, socket) call do_tcp_sendpages() one page at a
time, adding at most 4096 bytes to an skb. (assuming PAGE_SIZE=4096)

The call to tcp_push() at the end of do_tcp_sendpages() forces an
immediate xmit when pipe is not already filled, and tso_fragment() try
to split these skb to MSS multiples.

4096 bytes are usually split in a skb with 2 MSS, and a remaining
sub-mss skb (assuming MTU=1500)

This makes slow start suboptimal because many small frames are sent to
qdisc/driver layers instead of big ones (constrained by cwnd and packets
in flight of course)

In fact, applications using sendmsg() (adding an additional memory copy)
instead of vmsplice()/splice()/sendfile() are a bit faster because of
this anomaly, especially if serving small files in environments with
large initial [c]wnd.

Call tcp_push() only if MSG_MORE is not set in the flags parameter.

This bit is automatically provided by splice() internals but for the
last page, or on all pages if user specified SPLICE_F_MORE splice()
flag.

In some workloads, this can reduce number of sent logical packets by an
order of magnitude, making zero-copy TCP actually faster than
one-copy :)

Reported-by: Tom Herbert 
Cc: Nandita Dukkipati 
Cc: Neal Cardwell 
Cc: Tom Herbert 
Cc: Yuchung Cheng 
Cc: H.K. Jerry Chu 
Cc: Maciej Żenczykowski 
Cc: Mahesh Bandewar 
Cc: Ilpo Järvinen 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: reintroduce missing rcu_assign_pointer() calls

2012-02-03T17:22:20+00:00

[ Upstream commit cf778b00e96df6d64f8e21b8395d1f8a859ecdc7 ]

commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).

We miss needed barriers, even on x86, when y is not NULL.

Signed-off-by: Eric Dumazet 
CC: Stephen Hemminger 
CC: Paul E. McKenney 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'master' of github.com:davem330/net

2011-09-22T07:23:13+00:00

Conflicts:
	MAINTAINERS
	drivers/net/Kconfig
	drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c
	drivers/net/ethernet/broadcom/tg3.c
	drivers/net/wireless/iwlwifi/iwl-pci.c
	drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c
	drivers/net/wireless/rt2x00/rt2800usb.c
	drivers/net/wireless/wl12xx/main.c

sendmmsg/sendmsg: fix unsafe user pointer access

2011-08-25T02:45:03+00:00

Dereferencing a user pointer directly from kernel-space without going
through the copy_from_user family of functions is a bad idea. Two of
such usages can be found in the sendmsg code path called from sendmmsg,
added by

commit c71d8ebe7a4496fb7231151cb70a6baa0cb56f9a upstream.
commit 5b47b8038f183b44d2d8ff1c7d11a5c1be706b34 in the 3.0-stable tree.

Usages are performed through memcmp() and memcpy() directly. Fix those
by using the already copied msg_sys structure instead of the __user *msg
structure. Note that msg_sys can be set to NULL by verify_compat_iovec()
or verify_iovec(), which requires additional NULL pointer checks.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: David Goulet 
CC: Tetsuo Handa 
CC: Anton Blanchard 
CC: David S. Miller 
CC: stable 
Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net

2011-08-08T06:20:26+00:00

net: Fix security_socket_sendmsg() bypass problem.

2011-08-05T10:31:03+00:00

The sendmmsg() introduced by commit 228e548e "net: Add sendmmsg socket system
call" is capable of sending to multiple different destination addresses.

SMACK is using destination's address for checking sendmsg() permission.
However, security_socket_sendmsg() is called for only once even if multiple
different destination addresses are passed to sendmmsg().

Therefore, we need to call security_socket_sendmsg() for each destination
address rather than only the first destination address.

Since calling security_socket_sendmsg() every time when only single destination
address was passed to sendmmsg() is a waste of time, omit calling
security_socket_sendmsg() unless destination address of previous datagram and
that of current datagram differs.

Signed-off-by: Tetsuo Handa 
Acked-by: Anton Blanchard 
Cc: stable  [3.0+]
Signed-off-by: David S. Miller

net: Cap number of elements for sendmmsg

2011-08-05T10:31:03+00:00

To limit the amount of time we can spend in sendmmsg, cap the
number of elements to UIO_MAXIOV (currently 1024).

For error handling an application using sendmmsg needs to retry at
the first unsent message, so capping is simpler and requires less
application logic than returning EINVAL.

Signed-off-by: Anton Blanchard 
Cc: stable  [3.0+]
Signed-off-by: David S. Miller

net: sendmmsg should only return an error if no messages were sent

2011-08-05T10:31:02+00:00

sendmmsg uses a similar error return strategy as recvmmsg but it
turns out to be a confusing way to communicate errors.

The current code stores the error code away and returns it on the next
sendmmsg call. This means a call with completely valid arguments could
get an error from a previous call.

Change things so we only return an error if no datagrams could be sent.
If less than the requested number of messages were sent, the application
must retry starting at the first failed one and if the problem is
persistent the error will be returned.

This matches the behaviour of other syscalls like read/write - it
is not an error if less than the requested number of elements are sent.

Signed-off-by: Anton Blanchard 
Cc: stable  [3.0+]
Signed-off-by: David S. Miller

rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER

2011-08-02T11:29:23+00:00

When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// 

Signed-off-by: Stephen Hemminger 
Acked-by: Paul E. McKenney 
Signed-off-by: David S. Miller