linux.git/net/netlink, branch v3.19-rc2

netlink: Don't reorder loads/stores before marking mmap netlink frame as available

2014-12-18T17:35:55+00:00

Each mmap Netlink frame contains a status field which indicates
whether the frame is unused, reserved, contains data or needs to
be skipped. Both loads and stores may not be reordeded and must
complete before the status field is changed and another CPU might
pick up the frame for use. Use an smp_mb() to cover needs of both
types of callers to netlink_set_status(), callers which have been
reading data frame from the frame, and callers which have been
filling or releasing and thus writing to the frame.

- Example code path requiring a smp_rmb():
  memcpy(skb->data, (void *)hdr + NL_MMAP_HDRLEN, hdr->nm_len);
  netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED);

- Example code path requiring a smp_wmb():
  hdr->nm_uid	= from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid);
  hdr->nm_gid	= from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid);
  netlink_frame_flush_dcache(hdr);
  netlink_set_status(hdr, NL_MMAP_STATUS_VALID);

Fixes: f9c228 ("netlink: implement memory mapped recvmsg()")
Reported-by: Eric Dumazet 
Signed-off-by: Thomas Graf 
Signed-off-by: David S. Miller

netlink: Always copy on mmap TX.

2014-12-18T17:35:23+00:00

Checking the file f_count and the nlk->mapped count is not completely
sufficient to prevent the mmap'd area contents from changing from
under us during netlink mmap sendmsg() operations.

Be careful to sample the header's length field only once, because this
could change from under us as well.

Fixes: 5fd96123ee19 ("netlink: implement memory mapped sendmsg()")
Signed-off-by: David S. Miller 
Acked-by: Daniel Borkmann 
Acked-by: Thomas Graf

netlink: use jhash as hashfn for rhashtable

2014-12-10T20:17:45+00:00

For netlink, we shouldn't be using arch_fast_hash() as a hashing
discipline, but rather jhash() instead.

Since netlink sockets can be opened by any user, a local attacker
would be able to easily create collisions with the DPDK-derived
arch_fast_hash(), which trades off performance for security by
using crc32 CPU instructions on x86_64.

While it might have a legimite use case in other places, it should
be avoided in netlink context, though. As rhashtable's API is very
flexible, we could later on still decide on other hashing disciplines,
if legitimate.

Reference: http://thread.gmane.org/gmane.linux.kernel/1844123
Fixes: e341694e3eb5 ("netlink: Convert netlink_lookup() to use RCU protected hash table")
Cc: Herbert Xu 
Signed-off-by: Daniel Borkmann 
Acked-by: Thomas Graf 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

put iov_iter into msghdr

2014-12-09T21:29:03+00:00

Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.

Signed-off-by: Al Viro

new helper: memcpy_from_msg()

2014-11-24T09:28:48+00:00

Signed-off-by: Al Viro

netlink: Deletion of an unnecessary check before the function call "__module_get"

2014-11-19T20:27:40+00:00

The __module_get() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-11-14T06:01:12+00:00

Conflicts:
	drivers/net/ethernet/chelsio/cxgb4vf/sge.c
	drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c

sge.c was overlapping two changes, one to use the new
__dev_alloc_page() in net-next, and one to use s->fl_pg_order in net.

ixgbe_phy.c was a set of overlapping whitespace changes.

Signed-off-by: David S. Miller

rhashtable: Drop gfp_flags arg in insert/remove functions

2014-11-13T20:18:40+00:00

Reallocation is only required for shrinking and expanding and both rely
on a mutex for synchronization and callers of rhashtable_init() are in
non atomic context. Therefore, no reason to continue passing allocation
hints through the API.

Instead, use GFP_KERNEL and add __GFP_NOWARN | __GFP_NORETRY to allow
for silent fall back to vzalloc() without the OOM killer jumping in as
pointed out by Eric Dumazet and Eric W. Biederman.

Signed-off-by: Thomas Graf 
Signed-off-by: David S. Miller

rhashtable: Add parent argument to mutex_is_held

2014-11-13T20:13:05+00:00

Currently mutex_is_held can only test locks in the that are global
since it takes no arguments.  This prevents rhashtable from being
used in places where locks are lock, e.g., per-namespace locks.

This patch adds a parent field to mutex_is_held and rhashtable_params
so that local locks can be used (and tested).

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

netlink: Move mutex_is_held under PROVE_LOCKING

2014-11-13T20:13:05+00:00

The rhashtable function mutex_is_held is only used when PROVE_LOCKING
is enabled.  This patch modifies netlink so that we can rhashtable.h
itself can later make mutex_is_held optional depending on PROVE_LOCKING.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller