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author | Willem de Bruijn <willemb@google.com> | 2017-09-14 21:14:41 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-12 09:51:21 (GMT) |
commit | 6f7cdd4aa0a45f21edf6cb31236cd9d10c0d7992 (patch) | |
tree | db8973cdc140f6a5430c29a569c1a8cf0211ae05 /kernel | |
parent | 6eac2cd24bd97cb9eada99a01ee6022c573447de (diff) | |
download | linux-6f7cdd4aa0a45f21edf6cb31236cd9d10c0d7992.tar.xz |
packet: hold bind lock when rebinding to fanout hook
[ Upstream commit 008ba2a13f2d04c947adc536d19debb8fe66f110 ]
Packet socket bind operations must hold the po->bind_lock. This keeps
po->running consistent with whether the socket is actually on a ptype
list to receive packets.
fanout_add unbinds a socket and its packet_rcv/tpacket_rcv call, then
binds the fanout object to receive through packet_rcv_fanout.
Make it hold the po->bind_lock when testing po->running and rebinding.
Else, it can race with other rebind operations, such as that in
packet_set_ring from packet_rcv to tpacket_rcv. Concurrent updates
can result in a socket being added to a fanout group twice, causing
use-after-free KASAN bug reports, among others.
Reported independently by both trinity and syzkaller.
Verified that the syzkaller reproducer passes after this patch.
Fixes: dc99f600698d ("packet: Add fanout support.")
Reported-by: nixioaming <nixiaoming@huawei.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>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions