linux-stable.git/net/core, branch v3.18.78

net: Set sk_prot_creator when cloning sockets to the right proto

2017-10-21T15:07:25+00:00

[ Upstream commit 9d538fa60bad4f7b23193c89e843797a1cf71ef3 ]

sk->sk_prot and sk->sk_prot_creator can differ when the app uses
IPV6_ADDRFORM (transforming an IPv6-socket to an IPv4-one).
Which is why sk_prot_creator is there to make sure that sk_prot_free()
does the kmem_cache_free() on the right kmem_cache slab.

Now, if such a socket gets transformed back to a listening socket (using
connect() with AF_UNSPEC) we will allocate an IPv4 tcp_sock through
sk_clone_lock() when a new connection comes in. But sk_prot_creator will
still point to the IPv6 kmem_cache (as everything got copied in
sk_clone_lock()). When freeing, we will thus put this
memory back into the IPv6 kmem_cache although it was allocated in the
IPv4 cache. I have seen memory corruption happening because of this.

With slub-debugging and MEMCG_KMEM enabled this gives the warning
	"cache_from_obj: Wrong slab cache. TCPv6 but object is from TCP"

A C-program to trigger this:

void main(void)
{
        int fd = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
        int new_fd, newest_fd, client_fd;
        struct sockaddr_in6 bind_addr;
        struct sockaddr_in bind_addr4, client_addr1, client_addr2;
        struct sockaddr unsp;
        int val;

        memset(&bind_addr, 0, sizeof(bind_addr));
        bind_addr.sin6_family = AF_INET6;
        bind_addr.sin6_port = ntohs(42424);

        memset(&client_addr1, 0, sizeof(client_addr1));
        client_addr1.sin_family = AF_INET;
        client_addr1.sin_port = ntohs(42424);
        client_addr1.sin_addr.s_addr = inet_addr("127.0.0.1");

        memset(&client_addr2, 0, sizeof(client_addr2));
        client_addr2.sin_family = AF_INET;
        client_addr2.sin_port = ntohs(42421);
        client_addr2.sin_addr.s_addr = inet_addr("127.0.0.1");

        memset(&unsp, 0, sizeof(unsp));
        unsp.sa_family = AF_UNSPEC;

        bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr));

        listen(fd, 5);

        client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        connect(client_fd, (struct sockaddr *)&client_addr1, sizeof(client_addr1));
        new_fd = accept(fd, NULL, NULL);
        close(fd);

        val = AF_INET;
        setsockopt(new_fd, SOL_IPV6, IPV6_ADDRFORM, &val, sizeof(val));

        connect(new_fd, &unsp, sizeof(unsp));

        memset(&bind_addr4, 0, sizeof(bind_addr4));
        bind_addr4.sin_family = AF_INET;
        bind_addr4.sin_port = ntohs(42421);
        bind(new_fd, (struct sockaddr *)&bind_addr4, sizeof(bind_addr4));

        listen(new_fd, 5);

        client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        connect(client_fd, (struct sockaddr *)&client_addr2, sizeof(client_addr2));

        newest_fd = accept(new_fd, NULL, NULL);
        close(new_fd);

        close(client_fd);
        close(new_fd);
}

As far as I can see, this bug has been there since the beginning of the
git-days.

Signed-off-by: Christoph Paasch 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: core: Prevent from dereferencing null pointer when releasing SKB

2017-10-08T08:11:20+00:00

[ Upstream commit 9899886d5e8ec5b343b1efe44f185a0e68dc6454 ]

Added NULL check to make __dev_kfree_skb_irq consistent with kfree
family of functions.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=195289

Signed-off-by: Myungho Jung 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

net: avoid skb_warn_bad_offload false positives on UFO

2017-08-13T02:24:19+00:00

[ Upstream commit 8d63bee643f1fb53e472f0e135cae4eb99d62d19 ]

skb_warn_bad_offload triggers a warning when an skb enters the GSO
stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL
checksum offload set.

Commit b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise")
observed that SKB_GSO_DODGY producers can trigger the check and
that passing those packets through the GSO handlers will fix it
up. But, the software UFO handler will set ip_summed to
CHECKSUM_NONE.

When __skb_gso_segment is called from the receive path, this
triggers the warning again.

Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On
Tx these two are equivalent. On Rx, this better matches the
skb state (checksum computed), as CHECKSUM_NONE here means no
checksum computed.

See also this thread for context:
http://patchwork.ozlabs.org/patch/799015/

Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

rtnetlink: allocate more memory for dev_set_mac_address()

2017-08-11T16:30:14+00:00

[ Upstream commit 153711f9421be5dbc973dc57a4109dc9d54c89b1 ]

virtnet_set_mac_address() interprets mac address as struct
sockaddr, but upper layer only allocates dev->addr_len
which is ETH_ALEN + sizeof(sa_family_t) in this case.

We lack a unified definition for mac address, so just fix
the upper layer, this also allows drivers to interpret it
to struct sockaddr freely.

Reported-by: David Ahern 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Zero terminate ifr_name in dev_ifname().

2017-08-11T16:30:14+00:00

[ Upstream commit 63679112c536289826fec61c917621de95ba2ade ]

The ifr.ifr_name is passed around and assumed to be NULL terminated.

Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: skb_needs_check() accepts CHECKSUM_NONE for tx

2017-08-11T16:30:11+00:00

commit 6e7bc478c9a006c701c14476ec9d389a484b4864 upstream.

My recent change missed fact that UFO would perform a complete
UDP checksum before segmenting in frags.

In this case skb->ip_summed is set to CHECKSUM_NONE.

We need to add this valid case to skb_needs_check()

Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: Eric Dumazet 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: reduce skb_warn_bad_offload() noise

2017-08-11T16:30:08+00:00

commit b2504a5dbef3305ef41988ad270b0e8ec289331c upstream.

Dmitry reported warnings occurring in __skb_gso_segment() [1]

All SKB_GSO_DODGY producers can allow user space to feed
packets that trigger the current check.

We could prevent them from doing so, rejecting packets, but
this might add regressions to existing programs.

It turns out our SKB_GSO_DODGY handlers properly set up checksum
information that is needed anyway when packets needs to be segmented.

By checking again skb_needs_check() after skb_mac_gso_segment(),
we should remove these pesky warnings, at a very minor cost.

With help from Willem de Bruijn

[1]
WARNING: CPU: 1 PID: 6768 at net/core/dev.c:2439 skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434
lo: caps=(0x000000a2803b7c69, 0x0000000000000000) len=138 data_len=0 gso_size=15883 gso_type=4 ip_summed=0
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6768 Comm: syz-executor1 Not tainted 4.9.0 #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c063ecd8 ffffffff82346bdf ffffffff00000001 1ffff100380c7d2e
 ffffed00380c7d26 0000000041b58ab3 ffffffff84b37e38 ffffffff823468f1
 ffffffff84820740 ffffffff84f289c0 dffffc0000000000 ffff8801c063ee20
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:542
 [] warn_slowpath_fmt+0xc5/0x100 kernel/panic.c:565
 [] skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434
 [] __skb_gso_segment+0x482/0x780 net/core/dev.c:2706
 [] skb_gso_segment include/linux/netdevice.h:3985 [inline]
 [] validate_xmit_skb+0x5c9/0xc20 net/core/dev.c:2969
 [] __dev_queue_xmit+0xe6b/0x1e70 net/core/dev.c:3383
 [] dev_queue_xmit+0x17/0x20 net/core/dev.c:3424
 [] packet_snd net/packet/af_packet.c:2930 [inline]
 [] packet_sendmsg+0x32ed/0x4d30 net/packet/af_packet.c:2955
 [] sock_sendmsg_nosec net/socket.c:621 [inline]
 [] sock_sendmsg+0xca/0x110 net/socket.c:631
 [] ___sys_sendmsg+0x8fa/0x9f0 net/socket.c:1954
 [] __sys_sendmsg+0x138/0x300 net/socket.c:1988
 [] SYSC_sendmsg net/socket.c:1999 [inline]
 [] SyS_sendmsg+0x2d/0x50 net/socket.c:1995
 [] entry_SYSCALL_64_fastpath+0x1f/0xc2

Signed-off-by: Eric Dumazet 
Reported-by: Dmitry Vyukov  
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller 
Cc: Mark Salyzyn 
Signed-off-by: Greg Kroah-Hartman

net: prevent sign extension in dev_get_stats()

2017-07-21T06:12:21+00:00

commit 6f64ec74515925cced6df4571638b5a099a49aae upstream.

Similar to the fix provided by Dominik Heidler in commit
9b3dc0a17d73 ("l2tp: cast l2tp traffic counter to unsigned")
we need to take care of 32bit kernels in dev_get_stats().

When using atomic_long_read(), we add a 'long' to u64 and
might misinterpret high order bit, unless we cast to unsigned.

Fixes: caf586e5f23ce ("net: add a core netdev->rx_dropped counter")
Fixes: 015f0688f57ca ("net: net: add a core netdev->tx_dropped counter")
Fixes: 6e7333d315a76 ("net: add rx_nohandler stat counter")
Signed-off-by: Eric Dumazet 
Cc: Jarod Wilson 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Fix an intermittent pr_emerg warning about lo becoming free.

2017-07-05T12:35:12+00:00

[ Upstream commit f186ce61bb8235d80068c390dc2aad7ca427a4c2 ]

It looks like this:

Message from syslogd@flamingo at Apr 26 00:45:00 ...
 kernel:unregister_netdevice: waiting for lo to become free. Usage count = 4

They seem to coincide with net namespace teardown.

The message is emitted by netdev_wait_allrefs().

Forced a kdump in netdev_run_todo, but found that the refcount on the lo
device was already 0 at the time we got to the panic.

Used bcc to check the blocking in netdev_run_todo.  The only places
where we're off cpu there are in the rcu_barrier() and msleep() calls.
That behavior is expected.  The msleep time coincides with the amount of
time we spend waiting for the refcount to reach zero; the rcu_barrier()
wait times are not excessive.

After looking through the list of callbacks that the netdevice notifiers
invoke in this path, it appears that the dst_dev_event is the most
interesting.  The dst_ifdown path places a hold on the loopback_dev as
part of releasing the dev associated with the original dst cache entry.
Most of our notifier callbacks are straight-forward, but this one a)
looks complex, and b) places a hold on the network interface in
question.

I constructed a new bcc script that watches various events in the
liftime of a dst cache entry.  Note that dst_ifdown will take a hold on
the loopback device until the invalidated dst entry gets freed.

[      __dst_free] on DST: ffff883ccabb7900 IF tap1008300eth0 invoked at 1282115677036183
    __dst_free
    rcu_nocb_kthread
    kthread
    ret_from_fork
Acked-by: Eric Dumazet 

Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: don't call strlen on non-terminated string in dev_set_alias()

2017-07-05T12:35:12+00:00

[ Upstream commit c28294b941232931fbd714099798eb7aa7e865d7 ]

KMSAN reported a use of uninitialized memory in dev_set_alias(),
which was caused by calling strlcpy() (which in turn called strlen())
on the user-supplied non-terminated string.

Signed-off-by: Alexander Potapenko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman