linux-toradex.git/net/llc/llc_conn.c, branch v5.4-rc2

llc: set SOCK_RCU_FREE in llc_sap_add_socket()

2018-10-16T05:01:37+00:00

WHen an llc sock is added into the sk_laddr_hash of an llc_sap,
it is not marked with SOCK_RCU_FREE.

This causes that the sock could be freed while it is still being
read by __llc_lookup_established() with RCU read lock. sock is
refcounted, but with RCU read lock, nothing prevents the readers
getting a zero refcnt.

Fix it by setting SOCK_RCU_FREE in llc_sap_add_socket().

Reported-by: syzbot+11e05f04c15e03be5254@syzkaller.appspotmail.com
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

llc: delete timers synchronously in llc_sk_free()

2018-04-22T18:55:03+00:00

The connection timers of an llc sock could be still flying
after we delete them in llc_sk_free(), and even possibly
after we free the sock. We could just wait synchronously
here in case of troubles.

Note, I leave other call paths as they are, since they may
not have to wait, at least we can change them to synchronously
when needed.

Also, move the code to net/llc/llc_conn.c, which is apparently
a better place.

Reported-by: 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

llc: properly handle dev_queue_xmit() return value

2018-03-27T15:56:00+00:00

llc_conn_send_pdu() pushes the skb into write queue and
calls llc_conn_send_pdus() to flush them out. However, the
status of dev_queue_xmit() is not returned to caller,
in this case, llc_conn_state_process().

llc_conn_state_process() needs hold the skb no matter
success or failure, because it still uses it after that,
therefore we should hold skb before dev_queue_xmit() when
that skb is the one being processed by llc_conn_state_process().

For other callers, they can just pass NULL and ignore
the return value as they are.

Reported-by: Noam Rathaus 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

net: LLC: Convert timers to use timer_setup()

2017-10-25T03:06:25+00:00

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Hans Liljestrand 
Cc: "Paul E. McKenney" 
Cc: "Reshetova, Elena" 
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: David S. Miller

net: convert sock.sk_refcnt 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.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

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

mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU

2017-04-18T18:42:36+00:00

A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section.  Of course, that is not the
case.  Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.

However, there is a phrase for this, namely "type safety".  This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.

Signed-off-by: Paul E. McKenney 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Cc: Andrew Morton 
Cc: 
Acked-by: Johannes Weiner 
Acked-by: Vlastimil Babka 
[ paulmck: Add comments mentioning the old name, as requested by Eric
  Dumazet, in order to help people familiar with the old name find
  the new one. ]
Acked-by: David Rientjes

net/llc: avoid BUG_ON() in skb_orphan()

2017-02-13T03:14:49+00:00

It seems nobody used LLC since linux-3.12.

Fortunately fuzzers like syzkaller still know how to run this code,
otherwise it would be no fun.

Setting skb->sk without skb->destructor leads to all kinds of
bugs, we now prefer to be very strict about it.

Ideally here we would use skb_set_owner() but this helper does not exist yet,
only CAN seems to have a private helper for that.

Fixes: 376c7311bdb6 ("net: add a temporary sanity check in skb_orphan()")
Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Signed-off-by: David S. Miller

net: Pass kern from net_proto_family.create to sk_alloc

2015-05-11T14:50:17+00:00

In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller

llc: Make llc_conn_ev_qfyr_t function pointer arrays const

2014-12-10T20:21:24+00:00

It's better when function pointer arrays aren't modifiable.

Net change from original:

$ size net/llc/built-in.o.*
   text	   data	    bss	    dec	    hex	filename
  61065	  12886	   1344	  75295	  1261f	net/llc/built-in.o.new
  47113	  27030	   1344	  75487	  126df	net/llc/built-in.o.old

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller

llc: Make function pointer arrays const

2014-12-10T20:21:24+00:00

It's better when function pointer arrays aren't modifiable.

Signed-off-by: Joe Perches 
Signed-off-by: David S. Miller