Eric Dumazet
58cdc5947a
[ Upstream commit4179cb5a4c] 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.