linux.git/net/kcm, branch v4.13

kcm: do not attach PF_KCM sockets to avoid deadlock

2017-08-30T22:55:10+00:00

syzkaller had no problem to trigger a deadlock, attaching a KCM socket
to another one (or itself). (original syzkaller report was a very
confusing lockdep splat during a sendmsg())

It seems KCM claims to only support TCP, but no enforcement is done,
so we might need to add additional checks.

Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Signed-off-by: Eric Dumazet 
Reported-by: Dmitry Vyukov 
Acked-by: Tom Herbert 
Signed-off-by: David S. Miller

net: convert sock.sk_wmem_alloc from atomic_t to refcount_t

2017-07-01T14:39:08+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: David S. Miller

net: socket: mark socket protocol handler structs as const

2017-05-16T15:54:07+00:00

Signed-off-by: linzhang 
Signed-off-by: David S. Miller

kcm: remove a useless copy_from_user()

2017-04-17T17:28:48+00:00

struct kcm_clone only contains fd, and kcm_clone() only
writes this struct, so there is no need to copy it from user.

Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

kcm: return immediately after copy_from_user() failure

2017-03-24T20:13:53+00:00

There is no reason to continue after a copy_from_user()
failure.

Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

sched/headers: Prepare to move signal wakeup & sigpending methods from into

2017-03-02T07:42:32+00:00

Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

kcm: fix a null pointer dereference in kcm_sendmsg()

2017-02-14T18:06:37+00:00

In commit 98e3862ca2b1 ("kcm: fix 0-length case for kcm_sendmsg()")
I tried to avoid skb allocation for 0-length case, but missed
a check for NULL pointer in the non EOR case.

Fixes: 98e3862ca2b1 ("kcm: fix 0-length case for kcm_sendmsg()")
Reported-by: Dmitry Vyukov 
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Acked-by: Tom Herbert 
Signed-off-by: David S. Miller

kcm: fix 0-length case for kcm_sendmsg()

2017-02-09T21:38:48+00:00

Dmitry reported a kernel warning:

 WARNING: CPU: 3 PID: 2936 at net/kcm/kcmsock.c:627
 kcm_write_msgs+0x12e3/0x1b90 net/kcm/kcmsock.c:627
 CPU: 3 PID: 2936 Comm: a.out Not tainted 4.10.0-rc6+ #209
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:15 [inline]
  dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
  panic+0x1fb/0x412 kernel/panic.c:179
  __warn+0x1c4/0x1e0 kernel/panic.c:539
  warn_slowpath_null+0x2c/0x40 kernel/panic.c:582
  kcm_write_msgs+0x12e3/0x1b90 net/kcm/kcmsock.c:627
  kcm_sendmsg+0x163a/0x2200 net/kcm/kcmsock.c:1029
  sock_sendmsg_nosec net/socket.c:635 [inline]
  sock_sendmsg+0xca/0x110 net/socket.c:645
  sock_write_iter+0x326/0x600 net/socket.c:848
  new_sync_write fs/read_write.c:499 [inline]
  __vfs_write+0x483/0x740 fs/read_write.c:512
  vfs_write+0x187/0x530 fs/read_write.c:560
  SYSC_write fs/read_write.c:607 [inline]
  SyS_write+0xfb/0x230 fs/read_write.c:599
  entry_SYSCALL_64_fastpath+0x1f/0xc2

when calling syscall(__NR_write, sock2, 0x208aaf27ul, 0x0ul) on a KCM
seqpacket socket. It appears that kcm_sendmsg() does not handle len==0
case correctly, which causes an empty skb is allocated and queued.
Fix this by skipping the skb allocation for len==0 case.

Reported-by: Dmitry Vyukov 
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2016-10-07T22:36:58+00:00

Pull VFS splice updates from Al Viro:
 "There's a bunch of branches this cycle, both mine and from other folks
  and I'd rather send pull requests separately.

  This one is the conversion of ->splice_read() to ITER_PIPE iov_iter
  (and introduction of such). Gets rid of a lot of code in fs/splice.c
  and elsewhere; there will be followups, but these are for the next
  cycle...  Some pipe/splice-related cleanups from Miklos in the same
  branch as well"

* 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  pipe: fix comment in pipe_buf_operations
  pipe: add pipe_buf_steal() helper
  pipe: add pipe_buf_confirm() helper
  pipe: add pipe_buf_release() helper
  pipe: add pipe_buf_get() helper
  relay: simplify relay_file_read()
  switch default_file_splice_read() to use of pipe-backed iov_iter
  switch generic_file_splice_read() to use of ->read_iter()
  new iov_iter flavour: pipe-backed
  fuse_dev_splice_read(): switch to add_to_pipe()
  skb_splice_bits(): get rid of callback
  new helper: add_to_pipe()
  splice: lift pipe_lock out of splice_to_pipe()
  splice: switch get_iovec_page_array() to iov_iter
  splice_to_pipe(): don't open-code wakeup_pipe_readers()
  consistent treatment of EFAULT on O_DIRECT read/write

skb_splice_bits(): get rid of callback

2016-10-04T00:40:56+00:00

since pipe_lock is the outermost now, we don't need to drop/regain
socket locks around the call of splice_to_pipe() from skb_splice_bits(),
which kills the need to have a socket-specific callback; we can just
call splice_to_pipe() and be done with that.

Signed-off-by: Al Viro