linux-toradex.git/net/core, branch v5.3.2 Linux kernel for Apalis and Colibri modules udp: correct reuseport selection with connected sockets 2019-09-21T05:19:39+00:00 Willem de Bruijn willemb@google.com 2019-09-13T01:16:39+00:00 2053770ee6bbe237551df09fdec84282658083a2 [ Upstream commit acdcecc61285faed359f1a3568c32089cc3a8329 ] UDP reuseport groups can hold a mix unconnected and connected sockets. Ensure that connections only receive all traffic to their 4-tuple. Fast reuseport returns on the first reuseport match on the assumption that all matches are equal. Only if connections are present, return to the previous behavior of scoring all sockets. Record if connections are present and if so (1) treat such connected sockets as an independent match from the group, (2) only return 2-tuple matches from reuseport and (3) do not return on the first 2-tuple reuseport match to allow for a higher scoring match later. New field has_conns is set without locks. No other fields in the bitmap are modified at runtime and the field is only ever set unconditionally, so an RMW cannot miss a change. Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Link: http://lkml.kernel.org/r/CA+FuTSfRP09aJNYRt04SS6qj22ViiOEWaWmLAwX0psk8-PGNxw@mail.gmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Craig Gallek <kraig@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit acdcecc61285faed359f1a3568c32089cc3a8329 ]

UDP reuseport groups can hold a mix unconnected and connected sockets.
Ensure that connections only receive all traffic to their 4-tuple.

Fast reuseport returns on the first reuseport match on the assumption
that all matches are equal. Only if connections are present, return to
the previous behavior of scoring all sockets.

Record if connections are present and if so (1) treat such connected
sockets as an independent match from the group, (2) only return
2-tuple matches from reuseport and (3) do not return on the first
2-tuple reuseport match to allow for a higher scoring match later.

New field has_conns is set without locks. No other fields in the
bitmap are modified at runtime and the field is only ever set
unconditionally, so an RMW cannot miss a change.

Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection")
Link: http://lkml.kernel.org/r/CA+FuTSfRP09aJNYRt04SS6qj22ViiOEWaWmLAwX0psk8-PGNxw@mail.gmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Craig Gallek <kraig@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/sched: fix race between deactivation and dequeue for NOLOCK qdisc 2019-09-21T05:19:38+00:00 Paolo Abeni pabeni@redhat.com 2019-09-12T10:02:42+00:00 e0426ee9ad505871f8ed12bfd20d7d3ffbdbd241 [ Upstream commit d518d2ed8640c1cbbbb6f63939e3e65471817367 ] The test implemented by some_qdisc_is_busy() is somewhat loosy for NOLOCK qdisc, as we may hit the following scenario: CPU1 CPU2 // in net_tx_action() clear_bit(__QDISC_STATE_SCHED...); // in some_qdisc_is_busy() val = (qdisc_is_running(q) || test_bit(__QDISC_STATE_SCHED, &q->state)); // here val is 0 but... qdisc_run(q) // ... CPU1 is going to run the qdisc next As a conseguence qdisc_run() in net_tx_action() can race with qdisc_reset() in dev_qdisc_reset(). Such race is not possible for !NOLOCK qdisc as both the above bit operations are under the root qdisc lock(). After commit 021a17ed796b ("pfifo_fast: drop unneeded additional lock on dequeue") the race can cause use after free and/or null ptr dereference, but the root cause is likely older. This patch addresses the issue explicitly checking for deactivation under the seqlock for NOLOCK qdisc, so that the qdisc_run() in the critical scenario becomes a no-op. Note that the enqueue() op can still execute concurrently with dev_qdisc_reset(), but that is safe due to the skb_array() locking, and we can't avoid that for NOLOCK qdiscs. Fixes: 021a17ed796b ("pfifo_fast: drop unneeded additional lock on dequeue") Reported-by: Li Shuang <shuali@redhat.com> Reported-and-tested-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit d518d2ed8640c1cbbbb6f63939e3e65471817367 ]

The test implemented by some_qdisc_is_busy() is somewhat loosy for
NOLOCK qdisc, as we may hit the following scenario:

CPU1						CPU2
// in net_tx_action()
clear_bit(__QDISC_STATE_SCHED...);
						// in some_qdisc_is_busy()
						val = (qdisc_is_running(q) ||
						       test_bit(__QDISC_STATE_SCHED,
								&q->state));
						// here val is 0 but...
qdisc_run(q)
// ... CPU1 is going to run the qdisc next

As a conseguence qdisc_run() in net_tx_action() can race with qdisc_reset()
in dev_qdisc_reset(). Such race is not possible for !NOLOCK qdisc as
both the above bit operations are under the root qdisc lock().

After commit 021a17ed796b ("pfifo_fast: drop unneeded additional lock on dequeue")
the race can cause use after free and/or null ptr dereference, but the root
cause is likely older.

This patch addresses the issue explicitly checking for deactivation under
the seqlock for NOLOCK qdisc, so that the qdisc_run() in the critical
scenario becomes a no-op.

Note that the enqueue() op can still execute concurrently with dev_qdisc_reset(),
but that is safe due to the skb_array() locking, and we can't avoid that
for NOLOCK qdiscs.

Fixes: 021a17ed796b ("pfifo_fast: drop unneeded additional lock on dequeue")
Reported-by: Li Shuang <shuali@redhat.com>
Reported-and-tested-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: Fix null de-reference of device refcount 2019-09-12T10:55:34+00:00 Subash Abhinov Kasiviswanathan subashab@codeaurora.org 2019-09-10T20:02:57+00:00 10cc514f451a0f239aa34f91bc9dc954a9397840 In event of failure during register_netdevice, free_netdev is invoked immediately. free_netdev assumes that all the netdevice refcounts have been dropped prior to it being called and as a result frees and clears out the refcount pointer. However, this is not necessarily true as some of the operations in the NETDEV_UNREGISTER notifier handlers queue RCU callbacks for invocation after a grace period. The IPv4 callback in_dev_rcu_put tries to access the refcount after free_netdev is called which leads to a null de-reference- 44837.761523: <6> Unable to handle kernel paging request at virtual address 0000004a88287000 44837.761651: <2> pc : in_dev_finish_destroy+0x4c/0xc8 44837.761654: <2> lr : in_dev_finish_destroy+0x2c/0xc8 44837.762393: <2> Call trace: 44837.762398: <2> in_dev_finish_destroy+0x4c/0xc8 44837.762404: <2> in_dev_rcu_put+0x24/0x30 44837.762412: <2> rcu_nocb_kthread+0x43c/0x468 44837.762418: <2> kthread+0x118/0x128 44837.762424: <2> ret_from_fork+0x10/0x1c Fix this by waiting for the completion of the call_rcu() in case of register_netdevice errors. Fixes: 93ee31f14f6f ("[NET]: Fix free_netdev on register_netdev failure.") Cc: Sean Tranchetti <stranche@codeaurora.org> Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
In event of failure during register_netdevice, free_netdev is
invoked immediately. free_netdev assumes that all the netdevice
refcounts have been dropped prior to it being called and as a
result frees and clears out the refcount pointer.

However, this is not necessarily true as some of the operations
in the NETDEV_UNREGISTER notifier handlers queue RCU callbacks for
invocation after a grace period. The IPv4 callback in_dev_rcu_put
tries to access the refcount after free_netdev is called which
leads to a null de-reference-

44837.761523:   <6> Unable to handle kernel paging request at
                    virtual address 0000004a88287000
44837.761651:   <2> pc : in_dev_finish_destroy+0x4c/0xc8
44837.761654:   <2> lr : in_dev_finish_destroy+0x2c/0xc8
44837.762393:   <2> Call trace:
44837.762398:   <2>  in_dev_finish_destroy+0x4c/0xc8
44837.762404:   <2>  in_dev_rcu_put+0x24/0x30
44837.762412:   <2>  rcu_nocb_kthread+0x43c/0x468
44837.762418:   <2>  kthread+0x118/0x128
44837.762424:   <2>  ret_from_fork+0x10/0x1c

Fix this by waiting for the completion of the call_rcu() in
case of register_netdevice errors.

Fixes: 93ee31f14f6f ("[NET]: Fix free_netdev on register_netdev failure.")
Cc: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list 2019-09-07T15:58:48+00:00 Shmulik Ladkani shmulik@metanetworks.com 2019-09-06T09:23:50+00:00 3dcbdb134f329842a38f0e6797191b885ab00a00 Historically, support for frag_list packets entering skb_segment() was limited to frag_list members terminating on exact same gso_size boundaries. This is verified with a BUG_ON since commit 89319d3801d1 ("net: Add frag_list support to skb_segment"), quote: As such we require all frag_list members terminate on exact MSS boundaries. This is checked using BUG_ON. As there should only be one producer in the kernel of such packets, namely GRO, this requirement should not be difficult to maintain. However, since commit 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper"), the "exact MSS boundaries" assumption no longer holds: An eBPF program using bpf_skb_change_proto() DOES modify 'gso_size', but leaves the frag_list members as originally merged by GRO with the original 'gso_size'. Example of such programs are bpf-based NAT46 or NAT64. This lead to a kernel BUG_ON for flows involving: - GRO generating a frag_list skb - bpf program performing bpf_skb_change_proto() or bpf_skb_adjust_room() - skb_segment() of the skb See example BUG_ON reports in [0]. In commit 13acc94eff12 ("net: permit skb_segment on head_frag frag_list skb"), skb_segment() was modified to support the "gso_size mangling" case of a frag_list GRO'ed skb, but *only* for frag_list members having head_frag==true (having a page-fragment head). Alas, GRO packets having frag_list members with a linear kmalloced head (head_frag==false) still hit the BUG_ON. This commit adds support to skb_segment() for a 'head_skb' packet having a frag_list whose members are *non* head_frag, with gso_size mangled, by disabling SG and thus falling-back to copying the data from the given 'head_skb' into the generated segmented skbs - as suggested by Willem de Bruijn [1]. Since this approach involves the penalty of skb_copy_and_csum_bits() when building the segments, care was taken in order to enable this solution only when required: - untrusted gso_size, by testing SKB_GSO_DODGY is set (SKB_GSO_DODGY is set by any gso_size mangling functions in net/core/filter.c) - the frag_list is non empty, its item is a non head_frag, *and* the headlen of the given 'head_skb' does not match the gso_size. [0] https://lore.kernel.org/netdev/20190826170724.25ff616f@pixies/ https://lore.kernel.org/netdev/9265b93f-253d-6b8c-f2b8-4b54eff1835c@fb.com/ [1] https://lore.kernel.org/netdev/CA+FuTSfVsgNDi7c=GUU8nMg2hWxF2SjCNLXetHeVPdnxAW5K-w@mail.gmail.com/ Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper") Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Historically, support for frag_list packets entering skb_segment() was
limited to frag_list members terminating on exact same gso_size
boundaries. This is verified with a BUG_ON since commit 89319d3801d1
("net: Add frag_list support to skb_segment"), quote:

    As such we require all frag_list members terminate on exact MSS
    boundaries.  This is checked using BUG_ON.
    As there should only be one producer in the kernel of such packets,
    namely GRO, this requirement should not be difficult to maintain.

However, since commit 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper"),
the "exact MSS boundaries" assumption no longer holds:
An eBPF program using bpf_skb_change_proto() DOES modify 'gso_size', but
leaves the frag_list members as originally merged by GRO with the
original 'gso_size'. Example of such programs are bpf-based NAT46 or
NAT64.

This lead to a kernel BUG_ON for flows involving:
 - GRO generating a frag_list skb
 - bpf program performing bpf_skb_change_proto() or bpf_skb_adjust_room()
 - skb_segment() of the skb

See example BUG_ON reports in [0].

In commit 13acc94eff12 ("net: permit skb_segment on head_frag frag_list skb"),
skb_segment() was modified to support the "gso_size mangling" case of
a frag_list GRO'ed skb, but *only* for frag_list members having
head_frag==true (having a page-fragment head).

Alas, GRO packets having frag_list members with a linear kmalloced head
(head_frag==false) still hit the BUG_ON.

This commit adds support to skb_segment() for a 'head_skb' packet having
a frag_list whose members are *non* head_frag, with gso_size mangled, by
disabling SG and thus falling-back to copying the data from the given
'head_skb' into the generated segmented skbs - as suggested by Willem de
Bruijn [1].

Since this approach involves the penalty of skb_copy_and_csum_bits()
when building the segments, care was taken in order to enable this
solution only when required:
 - untrusted gso_size, by testing SKB_GSO_DODGY is set
   (SKB_GSO_DODGY is set by any gso_size mangling functions in
    net/core/filter.c)
 - the frag_list is non empty, its item is a non head_frag, *and* the
   headlen of the given 'head_skb' does not match the gso_size.

[0]
https://lore.kernel.org/netdev/20190826170724.25ff616f@pixies/
https://lore.kernel.org/netdev/9265b93f-253d-6b8c-f2b8-4b54eff1835c@fb.com/

[1]
https://lore.kernel.org/netdev/CA+FuTSfVsgNDi7c=GUU8nMg2hWxF2SjCNLXetHeVPdnxAW5K-w@mail.gmail.com/

Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper")
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: sock_map, fix missing ulp check in sock hash case 2019-09-05T09:56:19+00:00 John Fastabend john.fastabend@gmail.com 2019-09-03T20:24:50+00:00 44580a0118d3ede95fec4dce32df5f75f73cd663 sock_map and ULP only work together when ULP is loaded after the sock map is loaded. In the sock_map case we added a check for this to fail the load if ULP is already set. However, we missed the check on the sock_hash side. Add a ULP check to the sock_hash update path. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Reported-by: syzbot+7a6ee4d0078eac6bf782@syzkaller.appspotmail.com Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
sock_map and ULP only work together when ULP is loaded after the sock
map is loaded. In the sock_map case we added a check for this to fail
the load if ULP is already set. However, we missed the check on the
sock_hash side.

Add a ULP check to the sock_hash update path.

Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: syzbot+7a6ee4d0078eac6bf782@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fix skb use after free in netpoll 2019-08-28T03:52:02+00:00 Feng Sun loyou85@gmail.com 2019-08-26T06:46:04+00:00 2c1644cf6d46a8267d79ed95cb9b563839346562 After commit baeababb5b85d5c4e6c917efe2a1504179438d3b ("tun: return NET_XMIT_DROP for dropped packets"), when tun_net_xmit drop packets, it will free skb and return NET_XMIT_DROP, netpoll_send_skb_on_dev will run into following use after free cases: 1. retry netpoll_start_xmit with freed skb; 2. queue freed skb in npinfo->txq. queue_process will also run into use after free case. hit netpoll_send_skb_on_dev first case with following kernel log: [ 117.864773] kernel BUG at mm/slub.c:306! [ 117.864773] invalid opcode: 0000 [#1] SMP PTI [ 117.864774] CPU: 3 PID: 2627 Comm: loop_printmsg Kdump: loaded Tainted: P OE 5.3.0-050300rc5-generic #201908182231 [ 117.864775] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 117.864775] RIP: 0010:kmem_cache_free+0x28d/0x2b0 [ 117.864781] Call Trace: [ 117.864781] ? tun_net_xmit+0x21c/0x460 [ 117.864781] kfree_skbmem+0x4e/0x60 [ 117.864782] kfree_skb+0x3a/0xa0 [ 117.864782] tun_net_xmit+0x21c/0x460 [ 117.864782] netpoll_start_xmit+0x11d/0x1b0 [ 117.864788] netpoll_send_skb_on_dev+0x1b8/0x200 [ 117.864789] __br_forward+0x1b9/0x1e0 [bridge] [ 117.864789] ? skb_clone+0x53/0xd0 [ 117.864790] ? __skb_clone+0x2e/0x120 [ 117.864790] deliver_clone+0x37/0x50 [bridge] [ 117.864790] maybe_deliver+0x89/0xc0 [bridge] [ 117.864791] br_flood+0x6c/0x130 [bridge] [ 117.864791] br_dev_xmit+0x315/0x3c0 [bridge] [ 117.864792] netpoll_start_xmit+0x11d/0x1b0 [ 117.864792] netpoll_send_skb_on_dev+0x1b8/0x200 [ 117.864792] netpoll_send_udp+0x2c6/0x3e8 [ 117.864793] write_msg+0xd9/0xf0 [netconsole] [ 117.864793] console_unlock+0x386/0x4e0 [ 117.864793] vprintk_emit+0x17e/0x280 [ 117.864794] vprintk_default+0x29/0x50 [ 117.864794] vprintk_func+0x4c/0xbc [ 117.864794] printk+0x58/0x6f [ 117.864795] loop_fun+0x24/0x41 [printmsg_loop] [ 117.864795] kthread+0x104/0x140 [ 117.864795] ? 0xffffffffc05b1000 [ 117.864796] ? kthread_park+0x80/0x80 [ 117.864796] ret_from_fork+0x35/0x40 Signed-off-by: Feng Sun <loyou85@gmail.com> Signed-off-by: Xiaojun Zhao <xiaojunzhao141@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
After commit baeababb5b85d5c4e6c917efe2a1504179438d3b
("tun: return NET_XMIT_DROP for dropped packets"),
when tun_net_xmit drop packets, it will free skb and return NET_XMIT_DROP,
netpoll_send_skb_on_dev will run into following use after free cases:
1. retry netpoll_start_xmit with freed skb;
2. queue freed skb in npinfo->txq.
queue_process will also run into use after free case.

hit netpoll_send_skb_on_dev first case with following kernel log:

[  117.864773] kernel BUG at mm/slub.c:306!
[  117.864773] invalid opcode: 0000 [#1] SMP PTI
[  117.864774] CPU: 3 PID: 2627 Comm: loop_printmsg Kdump: loaded Tainted: P           OE     5.3.0-050300rc5-generic #201908182231
[  117.864775] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  117.864775] RIP: 0010:kmem_cache_free+0x28d/0x2b0
[  117.864781] Call Trace:
[  117.864781]  ? tun_net_xmit+0x21c/0x460
[  117.864781]  kfree_skbmem+0x4e/0x60
[  117.864782]  kfree_skb+0x3a/0xa0
[  117.864782]  tun_net_xmit+0x21c/0x460
[  117.864782]  netpoll_start_xmit+0x11d/0x1b0
[  117.864788]  netpoll_send_skb_on_dev+0x1b8/0x200
[  117.864789]  __br_forward+0x1b9/0x1e0 [bridge]
[  117.864789]  ? skb_clone+0x53/0xd0
[  117.864790]  ? __skb_clone+0x2e/0x120
[  117.864790]  deliver_clone+0x37/0x50 [bridge]
[  117.864790]  maybe_deliver+0x89/0xc0 [bridge]
[  117.864791]  br_flood+0x6c/0x130 [bridge]
[  117.864791]  br_dev_xmit+0x315/0x3c0 [bridge]
[  117.864792]  netpoll_start_xmit+0x11d/0x1b0
[  117.864792]  netpoll_send_skb_on_dev+0x1b8/0x200
[  117.864792]  netpoll_send_udp+0x2c6/0x3e8
[  117.864793]  write_msg+0xd9/0xf0 [netconsole]
[  117.864793]  console_unlock+0x386/0x4e0
[  117.864793]  vprintk_emit+0x17e/0x280
[  117.864794]  vprintk_default+0x29/0x50
[  117.864794]  vprintk_func+0x4c/0xbc
[  117.864794]  printk+0x58/0x6f
[  117.864795]  loop_fun+0x24/0x41 [printmsg_loop]
[  117.864795]  kthread+0x104/0x140
[  117.864795]  ? 0xffffffffc05b1000
[  117.864796]  ? kthread_park+0x80/0x80
[  117.864796]  ret_from_fork+0x35/0x40

Signed-off-by: Feng Sun <loyou85@gmail.com>
Signed-off-by: Xiaojun Zhao <xiaojunzhao141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sock: fix potential memory leak in proto_register() 2019-08-24T23:33:14+00:00 zhanglin zhang.lin16@zte.com.cn 2019-08-23T01:14:11+00:00 b45ce32135d1c82a5bf12aa56957c3fd27956057 If protocols registered exceeded PROTO_INUSE_NR, prot will be added to proto_list, but no available bit left for prot in proto_inuse_idx. Changes since v2: * Propagate the error code properly Signed-off-by: zhanglin <zhang.lin16@zte.com.cn> Signed-off-by: David S. Miller <davem@davemloft.net> 
If protocols registered exceeded PROTO_INUSE_NR, prot will be
added to proto_list, but no available bit left for prot in
proto_inuse_idx.

Changes since v2:
* Propagate the error code properly

Signed-off-by: zhanglin <zhang.lin16@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-08-24T00:34:11+00:00 David S. Miller davem@davemloft.net 2019-08-24T00:34:11+00:00 211c4624521527b19cb82ffd53fb34ae320059aa Daniel Borkmann says: ==================== pull-request: bpf 2019-08-24 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix verifier precision tracking with BPF-to-BPF calls, from Alexei. 2) Fix a use-after-free in prog symbol exposure, from Daniel. 3) Several s390x JIT fixes plus BE related fixes in BPF kselftests, from Ilya. 4) Fix memory leak by unpinning XDP umem pages in error path, from Ivan. 5) Fix a potential use-after-free on flow dissector detach, from Jakub. 6) Fix bpftool to close prog fd after showing metadata, from Quentin. 7) BPF kselftest config and TEST_PROGS_EXTENDED fixes, from Anders. ==================== Signed-off-by: David S. Miller <davem@davemloft.net> 
Daniel Borkmann says:

====================
pull-request: bpf 2019-08-24

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix verifier precision tracking with BPF-to-BPF calls, from Alexei.

2) Fix a use-after-free in prog symbol exposure, from Daniel.

3) Several s390x JIT fixes plus BE related fixes in BPF kselftests, from Ilya.

4) Fix memory leak by unpinning XDP umem pages in error path, from Ivan.

5) Fix a potential use-after-free on flow dissector detach, from Jakub.

6) Fix bpftool to close prog fd after showing metadata, from Quentin.

7) BPF kselftest config and TEST_PROGS_EXTENDED fixes, from Anders.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
bpf: allow narrow loads of some sk_reuseport_md fields with offset > 0 2019-08-23T23:25:41+00:00 Ilya Leoshkevich iii@linux.ibm.com 2019-08-20T15:50:25+00:00 2c238177bd7f4b14bdf7447cc1cd9bb791f147e6 test_select_reuseport fails on s390 due to verifier rejecting test_select_reuseport_kern.o with the following message: ; data_check.eth_protocol = reuse_md->eth_protocol; 18: (69) r1 = *(u16 *)(r6 +22) invalid bpf_context access off=22 size=2 This is because on big-endian machines casts from __u32 to __u16 are generated by referencing the respective variable as __u16 with an offset of 2 (as opposed to 0 on little-endian machines). The verifier already has all the infrastructure in place to allow such accesses, it's just that they are not explicitly enabled for eth_protocol field. Enable them for eth_protocol field by using bpf_ctx_range instead of offsetof. Ditto for ip_protocol, bind_inany and len, since they already allow narrowing, and the same problem can arise when working with them. Fixes: 2dbb9b9e6df6 ("bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
test_select_reuseport fails on s390 due to verifier rejecting
test_select_reuseport_kern.o with the following message:

	; data_check.eth_protocol = reuse_md->eth_protocol;
	18: (69) r1 = *(u16 *)(r6 +22)
	invalid bpf_context access off=22 size=2

This is because on big-endian machines casts from __u32 to __u16 are
generated by referencing the respective variable as __u16 with an offset
of 2 (as opposed to 0 on little-endian machines).

The verifier already has all the infrastructure in place to allow such
accesses, it's just that they are not explicitly enabled for
eth_protocol field. Enable them for eth_protocol field by using
bpf_ctx_range instead of offsetof.

Ditto for ip_protocol, bind_inany and len, since they already allow
narrowing, and the same problem can arise when working with them.

Fixes: 2dbb9b9e6df6 ("bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
flow_dissector: Fix potential use-after-free on BPF_PROG_DETACH 2019-08-23T23:15:34+00:00 Jakub Sitnicki jakub@cloudflare.com 2019-08-21T12:17:20+00:00 db38de39684dda2bf307f41797db2831deba64e9 Call to bpf_prog_put(), with help of call_rcu(), queues an RCU-callback to free the program once a grace period has elapsed. The callback can run together with new RCU readers that started after the last grace period. New RCU readers can potentially see the "old" to-be-freed or already-freed pointer to the program object before the RCU update-side NULLs it. Reorder the operations so that the RCU update-side resets the protected pointer before the end of the grace period after which the program will be freed. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Reported-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: Petar Penkov <ppenkov@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> 
Call to bpf_prog_put(), with help of call_rcu(), queues an RCU-callback to
free the program once a grace period has elapsed. The callback can run
together with new RCU readers that started after the last grace period.
New RCU readers can potentially see the "old" to-be-freed or already-freed
pointer to the program object before the RCU update-side NULLs it.

Reorder the operations so that the RCU update-side resets the protected
pointer before the end of the grace period after which the program will be
freed.

Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook")
Reported-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>