linux-stable.git/drivers/net/ppp, branch v3.18.25

ppp: fix pppoe_dev deletion condition in pppoe_release()

2015-12-03T15:11:30+00:00

[ Upstream commit 1acea4f6ce1b1c0941438aca75dd2e5c6b09db60 ]

We can't rely on PPPOX_ZOMBIE to decide whether to clear po->pppoe_dev.
PPPOX_ZOMBIE can be set by pppoe_disc_rcv() even when po->pppoe_dev is
NULL. So we have no guarantee that (sk->sk_state & PPPOX_ZOMBIE) implies
(po->pppoe_dev != NULL).
Since we're releasing a PPPoE socket, we want to release the pppoe_dev
if it exists and reset sk_state to PPPOX_DEAD, no matter the previous
value of sk_state. So we can just check for po->pppoe_dev and avoid any
assumption on sk->sk_state.

Fixes: 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ppp: don't override sk->sk_state in pppoe_flush_dev()

2015-11-13T18:17:05+00:00

[ Upstream commit e6740165b8f7f06d8caee0fceab3fb9d790a6fed ]

Since commit 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release"),
pppoe_release() calls dev_put(po->pppoe_dev) if sk is in the
PPPOX_ZOMBIE state. But pppoe_flush_dev() can set sk->sk_state to
PPPOX_ZOMBIE _and_ reset po->pppoe_dev to NULL. This leads to the
following oops:

[  570.140800] BUG: unable to handle kernel NULL pointer dereference at 00000000000004e0
[  570.142931] IP: [] pppoe_release+0x50/0x101 [pppoe]
[  570.144601] PGD 3d119067 PUD 3dbc1067 PMD 0
[  570.144601] Oops: 0000 [#1] SMP
[  570.144601] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6_udp_tunnel udp_tunnel pppoe pppox ppp_generic slhc loop crc32c_intel ghash_clmulni_intel jitterentropy_rng sha256_generic hmac drbg ansi_cprng aesni_intel aes_x86_64 ablk_helper cryptd lrw gf128mul glue_helper acpi_cpufreq evdev serio_raw processor button ext4 crc16 mbcache jbd2 virtio_net virtio_blk virtio_pci virtio_ring virtio
[  570.144601] CPU: 1 PID: 15738 Comm: ppp-apitest Not tainted 4.2.0 #1
[  570.144601] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[  570.144601] task: ffff88003d30d600 ti: ffff880036b60000 task.ti: ffff880036b60000
[  570.144601] RIP: 0010:[]  [] pppoe_release+0x50/0x101 [pppoe]
[  570.144601] RSP: 0018:ffff880036b63e08  EFLAGS: 00010202
[  570.144601] RAX: 0000000000000000 RBX: ffff880034340000 RCX: 0000000000000206
[  570.144601] RDX: 0000000000000006 RSI: ffff88003d30dd20 RDI: ffff88003d30dd20
[  570.144601] RBP: ffff880036b63e28 R08: 0000000000000001 R09: 0000000000000000
[  570.144601] R10: 00007ffee9b50420 R11: ffff880034340078 R12: ffff8800387ec780
[  570.144601] R13: ffff8800387ec7b0 R14: ffff88003e222aa0 R15: ffff8800387ec7b0
[  570.144601] FS:  00007f5672f48700(0000) GS:ffff88003fc80000(0000) knlGS:0000000000000000
[  570.144601] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  570.144601] CR2: 00000000000004e0 CR3: 0000000037f7e000 CR4: 00000000000406a0
[  570.144601] Stack:
[  570.144601]  ffffffffa018f240 ffff8800387ec780 ffffffffa018f240 ffff8800387ec7b0
[  570.144601]  ffff880036b63e48 ffffffff812caabe ffff880039e4e000 0000000000000008
[  570.144601]  ffff880036b63e58 ffffffff812cabad ffff880036b63ea8 ffffffff811347f5
[  570.144601] Call Trace:
[  570.144601]  [] sock_release+0x1a/0x75
[  570.144601]  [] sock_close+0xd/0x11
[  570.144601]  [] __fput+0xff/0x1a5
[  570.144601]  [] ____fput+0x9/0xb
[  570.144601]  [] task_work_run+0x66/0x90
[  570.144601]  [] prepare_exit_to_usermode+0x8c/0xa7
[  570.144601]  [] syscall_return_slowpath+0x16d/0x19b
[  570.144601]  [] int_ret_from_sys_call+0x25/0x9f
[  570.144601] Code: 48 8b 83 c8 01 00 00 a8 01 74 12 48 89 df e8 8b 27 14 e1 b8 f7 ff ff ff e9 b7 00 00 00 8a 43 12 a8 0b 74 1c 48 8b 83 a8 04 00 00 <48> 8b 80 e0 04 00 00 65 ff 08 48 c7 83 a8 04 00 00 00 00 00 00
[  570.144601] RIP  [] pppoe_release+0x50/0x101 [pppoe]
[  570.144601]  RSP 
[  570.144601] CR2: 00000000000004e0
[  570.200518] ---[ end trace 46956baf17349563 ]---

pppoe_flush_dev() has no reason to override sk->sk_state with
PPPOX_ZOMBIE. pppox_unbind_sock() already sets sk->sk_state to
PPPOX_DEAD, which is the correct state given that sk is unbound and
po->pppoe_dev is NULL.

Fixes: 2b018d57ff18 ("pppoe: drop PPPOX_ZOMBIEs in pppoe_release")
Tested-by: Oleksii Berezhniak 
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ppp: call skb_checksum_complete_unset in ppp_receive_frame

2015-05-11T11:07:56+00:00

[ Upstream commit 3dfb05340ec6676e6fc71a9ae87bbbe66d3c2998 ]

Call checksum_complete_unset in PPP receive to discard checksum-complete
value. PPP does not pull checksum for headers and also modifies packet
as in VJ compression.

Signed-off-by: Tom Herbert 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ppp: deflate: never return len larger than output buffer

2015-02-27T01:49:01+00:00

[ Upstream commit e2a4800e75780ccf4e6c2487f82b688ba736eb18 ]

When we've run out of space in the output buffer to store more data, we
will call zlib_deflate with a NULL output buffer until we've consumed
remaining input.

When this happens, olen contains the size the output buffer would have
consumed iff we'd have had enough room.

This can later cause skb_over_panic when ppp_generic skb_put()s
the returned length.

Reported-by: Iain Douglas 
Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

pptp: fix stack info leak in pptp_getname()

2014-11-21T03:43:47+00:00

pptp_getname() only partially initializes the stack variable sa,
particularly only fills the pptp part of the sa_addr union. The code
thereby discloses 16 bytes of kernel stack memory via getsockname().

Fix this by memset(0)'ing the union before.

Cc: Dmitry Kozlov 
Signed-off-by: Mathias Krause 
Signed-off-by: David S. Miller

net: ppp: Don't call bpf_prog_create() in ppp_lock

2014-11-11T20:15:03+00:00

In ppp_ioctl(), bpf_prog_create() is called inside ppp_lock, which
eventually calls vmalloc() and hits BUG_ON() in vmalloc.c.  This patch
works around the problem by moving the allocation outside the lock.

The bug was revealed by the recent change in net/core/filter.c, as it
allocates via vmalloc() instead of kmalloc() now.

Reported-and-tested-by: Stefan Seyfried 
Signed-off-by: Takashi Iwai 
Signed-off-by: David S. Miller

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2014-10-13T09:28:42+00:00

Pull vfs updates from Al Viro:
 "The big thing in this pile is Eric's unmount-on-rmdir series; we
  finally have everything we need for that.  The final piece of prereqs
  is delayed mntput() - now filesystem shutdown always happens on
  shallow stack.

  Other than that, we have several new primitives for iov_iter (Matt
  Wilcox, culled from his XIP-related series) pushing the conversion to
  ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c
  cleanups and fixes (including the external name refcounting, which
  gives consistent behaviour of d_move() wrt procfs symlinks for long
  and short names alike) and assorted cleanups and fixes all over the
  place.

  This is just the first pile; there's a lot of stuff from various
  people that ought to go in this window.  Starting with
  unionmount/overlayfs mess...  ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits)
  fs/file_table.c: Update alloc_file() comment
  vfs: Deduplicate code shared by xattr system calls operating on paths
  reiserfs: remove pointless forward declaration of struct nameidata
  don't need that forward declaration of struct nameidata in dcache.h anymore
  take dname_external() into fs/dcache.c
  let path_init() failures treated the same way as subsequent link_path_walk()
  fix misuses of f_count() in ppp and netlink
  ncpfs: use list_for_each_entry() for d_subdirs walk
  vfs: move getname() from callers to do_mount()
  gfs2_atomic_open(): skip lookups on hashed dentry
  [infiniband] remove pointless assignments
  gadgetfs: saner API for gadgetfs_create_file()
  f_fs: saner API for ffs_sb_create_file()
  jfs: don't hash direct inode
  [s390] remove pointless assignment of ->f_op in vmlogrdr ->open()
  ecryptfs: ->f_op is never NULL
  android: ->f_op is never NULL
  nouveau: __iomem misannotations
  missing annotation in fs/file.c
  fs: namespace: suppress 'may be used uninitialized' warnings
  ...

fix misuses of f_count() in ppp and netlink

2014-10-09T06:39:17+00:00

we used to check for "nobody else could start doing anything with
that opened file" by checking that refcount was 2 or less - one
for descriptor table and one we'd acquired in fget() on the way to
wherever we are.  That was race-prone (somebody else might have
had a reference to descriptor table and do fget() just as we'd
been checking) and it had become flat-out incorrect back when
we switched to fget_light() on those codepaths - unlike fget(),
it doesn't grab an extra reference unless the descriptor table
is shared.  The same change allowed a race-free check, though -
we are safe exactly when refcount is less than 2.

It was a long time ago; pre-2.6.12 for ioctl() (the codepath leading
to ppp one) and 2.6.17 for sendmsg() (netlink one).  OTOH,
netlink hadn't grown that check until 3.9 and ppp used to live
in drivers/net, not drivers/net/ppp until 3.1.  The bug existed
well before that, though, and the same fix used to apply in old
location of file.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro

net: better IFF_XMIT_DST_RELEASE support

2014-10-07T17:22:11+00:00

Testing xmit_more support with netperf and connected UDP sockets,
I found strange dst refcount false sharing.

Current handling of IFF_XMIT_DST_RELEASE is not optimal.

Dropping dst in validate_xmit_skb() is certainly too late in case
packet was queued by cpu X but dequeued by cpu Y

The logical point to take care of drop/force is in __dev_queue_xmit()
before even taking qdisc lock.

As Julian Anastasov pointed out, need for skb_dst() might come from some
packet schedulers or classifiers.

This patch adds new helper to cleanly express needs of various drivers
or qdiscs/classifiers.

Drivers that need skb_dst() in their ndo_start_xmit() should call
following helper in their setup instead of the prior :

	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
->
	netif_keep_dst(dev);

Instead of using a single bit, we use two bits, one being
eventually rebuilt in bonding/team drivers.

The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being
rebuilt in bonding/team. Eventually, we could add something
smarter later.

Signed-off-by: Eric Dumazet 
Cc: Julian Anastasov 
Signed-off-by: David S. Miller

net: filter: split 'struct sk_filter' into socket and bpf parts

2014-08-02T22:03:58+00:00

clean up names related to socket filtering and bpf in the following way:
- everything that deals with sockets keeps 'sk_*' prefix
- everything that is pure BPF is changed to 'bpf_*' prefix

split 'struct sk_filter' into
struct sk_filter {
	atomic_t        refcnt;
	struct rcu_head rcu;
	struct bpf_prog *prog;
};
and
struct bpf_prog {
        u32                     jited:1,
                                len:31;
        struct sock_fprog_kern  *orig_prog;
        unsigned int            (*bpf_func)(const struct sk_buff *skb,
                                            const struct bpf_insn *filter);
        union {
                struct sock_filter      insns[0];
                struct bpf_insn         insnsi[0];
                struct work_struct      work;
        };
};
so that 'struct bpf_prog' can be used independent of sockets and cleans up
'unattached' bpf use cases

split SK_RUN_FILTER macro into:
    SK_RUN_FILTER to be used with 'struct sk_filter *' and
    BPF_PROG_RUN to be used with 'struct bpf_prog *'

__sk_filter_release(struct sk_filter *) gains
__bpf_prog_release(struct bpf_prog *) helper function

also perform related renames for the functions that work
with 'struct bpf_prog *', since they're on the same lines:

sk_filter_size -> bpf_prog_size
sk_filter_select_runtime -> bpf_prog_select_runtime
sk_filter_free -> bpf_prog_free
sk_unattached_filter_create -> bpf_prog_create
sk_unattached_filter_destroy -> bpf_prog_destroy
sk_store_orig_filter -> bpf_prog_store_orig_filter
sk_release_orig_filter -> bpf_release_orig_filter
__sk_migrate_filter -> bpf_migrate_filter
__sk_prepare_filter -> bpf_prepare_filter

API for attaching classic BPF to a socket stays the same:
sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *)
and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program
which is used by sockets, tun, af_packet

API for 'unattached' BPF programs becomes:
bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *)
and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program
which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf

Signed-off-by: Alexei Starovoitov 
Signed-off-by: David S. Miller