linux.git/net/xdp, branch v4.19.145

xdp: Fix xsk_generic_xmit errno

2020-06-25T13:33:05+00:00

[ Upstream commit aa2cad0600ed2ca6a0ab39948d4db1666b6c962b ]

Propagate sock_alloc_send_skb error code, not set it to
EAGAIN unconditionally, when fail to allocate skb, which
might cause that user space unnecessary loops.

Fixes: 35fcde7f8deb ("xsk: support for Tx")
Signed-off-by: Li RongQing 
Signed-off-by: Daniel Borkmann 
Acked-by: Björn Töpel 
Link: https://lore.kernel.org/bpf/1591852266-24017-1-git-send-email-lirongqing@baidu.com
Signed-off-by: Sasha Levin

xsk: Add overflow check for u64 division, stored into u32

2020-06-03T06:19:48+00:00

commit b16a87d0aef7a6be766f6618976dc5ff2c689291 upstream.

The npgs member of struct xdp_umem is an u32 entity, and stores the
number of pages the UMEM consumes. The calculation of npgs

  npgs = size / PAGE_SIZE

can overflow.

To avoid overflow scenarios, the division is now first stored in a
u64, and the result is verified to fit into 32b.

An alternative would be storing the npgs as a u64, however, this
wastes memory and is an unrealisticly large packet area.

Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt")
Reported-by: "Minh Bùi Quang" 
Signed-off-by: Björn Töpel 
Signed-off-by: Daniel Borkmann 
Acked-by: Jonathan Lemon 
Link: https://lore.kernel.org/bpf/CACtPs=GGvV-_Yj6rbpzTVnopgi5nhMoCcTkSkYrJHGQHJWFZMQ@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20200525080400.13195-1-bjorn.topel@gmail.com
Signed-off-by: Greg Kroah-Hartman

xsk: Add missing check on user supplied headroom size

2020-04-23T08:30:15+00:00

[ Upstream commit 99e3a236dd43d06c65af0a2ef9cb44306aef6e02 ]

Add a check that the headroom cannot be larger than the available
space in the chunk. In the current code, a malicious user can set the
headroom to a value larger than the chunk size minus the fixed XDP
headroom. That way packets with a length larger than the supported
size in the umem could get accepted and result in an out-of-bounds
write.

Fixes: c0c77d8fb787 ("xsk: add user memory registration support sockopt")
Reported-by: Bui Quang Minh 
Signed-off-by: Magnus Karlsson 
Signed-off-by: Daniel Borkmann 
Link: https://bugzilla.kernel.org/show_bug.cgi?id=207225
Link: https://lore.kernel.org/bpf/1586849715-23490-1-git-send-email-magnus.karlsson@intel.com
Signed-off-by: Sasha Levin

xsk: Fix registration of Rx-only sockets

2020-01-27T13:51:19+00:00

[ Upstream commit 2afd23f78f39da84937006ecd24aa664a4ab052b ]

Having Rx-only AF_XDP sockets can potentially lead to a crash in the
system by a NULL pointer dereference in xsk_umem_consume_tx(). This
function iterates through a list of all sockets tied to a umem and
checks if there are any packets to send on the Tx ring. Rx-only
sockets do not have a Tx ring, so this will cause a NULL pointer
dereference. This will happen if you have registered one or more
Rx-only sockets to a umem and the driver is checking the Tx ring even
on Rx, or if the XDP_SHARED_UMEM mode is used and there is a mix of
Rx-only and other sockets tied to the same umem.

Fixed by only putting sockets with a Tx component on the list that
xsk_umem_consume_tx() iterates over.

Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions")
Reported-by: Kal Cutter Conley 
Signed-off-by: Magnus Karlsson 
Signed-off-by: Alexei Starovoitov 
Acked-by: Jonathan Lemon 
Link: https://lore.kernel.org/bpf/1571645818-16244-1-git-send-email-magnus.karlsson@intel.com
Signed-off-by: Sasha Levin

xsk: avoid store-tearing when assigning umem

2020-01-27T13:51:10+00:00

[ Upstream commit 9764f4b301c3e7eb3b75eec85b73cad449cdbb0d ]

The umem member of struct xdp_sock is read outside of the control
mutex, in the mmap implementation, and needs a WRITE_ONCE to avoid
potential store-tearing.

Acked-by: Jonathan Lemon 
Fixes: 423f38329d26 ("xsk: add umem fill queue support and mmap")
Signed-off-by: Björn Töpel 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin

xsk: avoid store-tearing when assigning queues

2020-01-27T13:51:10+00:00

[ Upstream commit 94a997637c5b562fa0ca44fca1d2cd02ec08236f ]

Use WRITE_ONCE when doing the store of tx, rx, fq, and cq, to avoid
potential store-tearing. These members are read outside of the control
mutex in the mmap implementation.

Acked-by: Jonathan Lemon 
Fixes: 37b076933a8e ("xsk: add missing write- and data-dependency barrier")
Signed-off-by: Björn Töpel 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin

xdp: fix possible cq entry leak

2020-01-27T13:51:01+00:00

[ Upstream commit 675716400da6f15b9d3db04ef74ee74ca9a00af3 ]

Completion queue address reservation could not be undone.
In case of bad 'queue_id' or skb allocation failure, reserved entry
will be leaked reducing the total capacity of completion queue.

Fix that by moving reservation to the point where failure is not
possible. Additionally, 'queue_id' checking moved out from the loop
since there is no point to check it there.

Fixes: 35fcde7f8deb ("xsk: support for Tx")
Signed-off-by: Ilya Maximets 
Acked-by: Björn Töpel 
Tested-by: William Tu 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin

xsk: add missing smp_rmb() in xsk_mmap

2020-01-27T13:50:21+00:00

[ Upstream commit e6762c8bcf982821935a2b1cb33cf8335d0eefae ]

All the setup code in AF_XDP is protected by a mutex with the
exception of the mmap code that cannot use it. To make sure that a
process banging on the mmap call at the same time as another process
is setting up the socket, smp_wmb() calls were added in the umem
registration code and the queue creation code, so that the published
structures that xsk_mmap needs would be consistent. However, the
corresponding smp_rmb() calls were not added to the xsk_mmap
code. This patch adds these calls.

Fixes: 37b076933a8e3 ("xsk: add missing write- and data-dependency barrier")
Fixes: c0c77d8fb787c ("xsk: add user memory registration support sockopt")
Signed-off-by: Magnus Karlsson 
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

xsk: proper AF_XDP socket teardown ordering

2019-11-24T07:20:32+00:00

[ Upstream commit 541d7fdd7694560404c502f64298a90ffe017e6b ]

The AF_XDP socket struct can exist in three different, implicit
states: setup, bound and released. Setup is prior the socket has been
bound to a device. Bound is when the socket is active for receive and
send. Released is when the process/userspace side of the socket is
released, but the sock object is still lingering, e.g. when there is a
reference to the socket in an XSKMAP after process termination.

The Rx fast-path code uses the "dev" member of struct xdp_sock to
check whether a socket is bound or relased, and the Tx code uses the
struct xdp_umem "xsk_list" member in conjunction with "dev" to
determine the state of a socket.

However, the transition from bound to released did not tear the socket
down in correct order.

On the Rx side "dev" was cleared after synchronize_net() making the
synchronization useless. On the Tx side, the internal queues were
destroyed prior removing them from the "xsk_list".

This commit corrects the cleanup order, and by doing so
xdp_del_sk_umem() can be simplified and one synchronize_net() can be
removed.

Fixes: 965a99098443 ("xsk: add support for bind for Rx")
Fixes: ac98d8aab61b ("xsk: wire upp Tx zero-copy functions")
Reported-by: Jesper Dangaard Brouer 
Signed-off-by: Björn Töpel 
Acked-by: Song Liu 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin

xdp: unpin xdp umem pages in error path

2019-09-21T05:16:57+00:00

[ Upstream commit fb89c39455e4b49881c5a42761bd71f03d3ef888 ]

Fix mem leak caused by missed unpin routine for umem pages.

Fixes: 8aef7340ae9695 ("xsk: introduce xdp_umem_page")
Signed-off-by: Ivan Khoronzhuk 
Acked-by: Jonathan Lemon 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Sasha Levin