'family' can be a user-controlled value, so sanitize it after the bounds
check to avoid speculative out-of-bounds access.

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

'call' is a user-controlled value, so sanitize the array index after the
bounds check to avoid speculating past the bounds of the 'nargs' array.

Found with the help of Smatch:

net/socket.c:2508 __do_sys_socketcall() warn: potential spectre issue
'nargs' [r] (local cap)

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The big aio poll revert broke various network protocols that don't
implement ->poll as a patch in the aio poll serie removed sock_no_poll
and made the common code handle this case.

Reported-by: syzbot+57727883dbad76db2ef0@syzkaller.appspotmail.com
Reported-by: syzbot+cdb0d3176b53d35ad454@syzkaller.appspotmail.com
Reported-by: syzbot+2c7e8f74f8b2571c87e8@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Fixes: a11e1d432b51 ("Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fchownat() doesn't even hold refcnt of fd until it figures out
fd is really needed (otherwise is ignored) and releases it after
it resolves the path. This means sock_close() could race with
sockfs_setattr(), which leads to a NULL pointer dereference
since typically we set sock->sk to NULL in ->release().

As pointed out by Al, this is unique to sockfs. So we can fix this
in socket layer by acquiring inode_lock in sock_close() and
checking against NULL in sockfs_setattr().

sock_release() is called in many places, only the sock_close()
path matters here. And fortunately, this should not affect normal
sock_close() as it is only called when the last fd refcnt is gone.
It only affects sock_close() with a parallel sockfs_setattr() in
progress, which is not common.

Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.")
Reported-by: shankarapailoor <shankarapailoor@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull security system updates from James Morris:

 - incorporate new socketpair() hook into LSM and wire up the SELinux
   and Smack modules. From David Herrmann:

     "The idea is to allow SO_PEERSEC to be called on AF_UNIX sockets
      created via socketpair(2), and return the same information as if
      you emulated socketpair(2) via a temporary listener socket.

      Right now SO_PEERSEC will return the unlabeled credentials for a
      socketpair, rather than the actual credentials of the creating
      process."

 - remove the unused security_settime LSM hook (Sargun Dhillon).

 - remove some stack allocated arrays from the keys code (Tycho
   Andersen)

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  dh key: get rid of stack allocated array for zeroes
  dh key: get rid of stack allocated array
  big key: get rid of stack array allocation
  smack: provide socketpair callback
  selinux: provide socketpair callback
  net: hook socketpair() into LSM
  security: add hook for socketpair()
  security: remove security_settime

The socket file operations still implement ->poll until all protocols are
switched over.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Factor out two busy poll related helpers for late reuse, and remove
a command that isn't very helpful, especially with the __poll_t
annotations in place.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Use the newly created LSM-hook for socketpair(). The default hook
return-value is 0, so behavior stays the same unless LSMs start using
this hook.

Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <james.morris@microsoft.com>

Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  kfifo: fix inaccurate comment
  tools/thermal: tmon: fix for segfault
  net: Spelling s/stucture/structure/
  edd: don't spam log if no EDD information is present
  Documentation: Fix early-microcode.txt references after file rename
  tracing: Block comments should align the * on each line
  treewide: Fix typos in printk
  GenWQE: Fix a typo in two comments
  treewide: Align function definition open/close braces