4179cb5a4c
netif_rx() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Otherwise we risk use-after-free and/or crashes. Note this patch also fixes a small issue that came with commitce6502a8f9("vxlan: fix a use after free in vxlan_encap_bypass"), since the dev->stats.rx_dropped change was done on the wrong device. Fixes:d342894c5d("vxlan: virtual extensible lan") Fixes:ce6502a8f9("vxlan: fix a use after free in vxlan_encap_bypass") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Petr Machata <petrm@mellanox.com> Cc: Ido Schimmel <idosch@mellanox.com> Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Cc: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.