Eric Dumazet
8f50a05dd6
[ Upstream commit1efba987c4] If both IFF_NAPI_FRAGS mode and XDP are enabled, and the XDP program consumes the skb, we need to clear the napi.skb (or risk a use-after-free) and release the mutex (or risk a deadlock) WARNING: lock held when returning to user space! 5.5.0-rc6-syzkaller #0 Not tainted ------------------------------------------------ syz-executor.0/455 is leaving the kernel with locks still held! 1 lock held by syz-executor.0/455: #0: ffff888098f6e748 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x1604/0x3fc0 drivers/net/tun.c:1835 Fixes:90e33d4594("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Petar Penkov <ppenkov@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.
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.