382f57b996
[ Upstream commit 7c74b0bec918c1e0ca0b4208038c156eacf8f13f ]
A user reported [0] hitting the WARN_ON in fib_info_nh:
[ 8633.839816] ------------[ cut here ]------------
[ 8633.839819] WARNING: CPU: 0 PID: 1719 at include/net/nexthop.h:251 fib_select_path+0x303/0x381
...
[ 8633.839846] RIP: 0010:fib_select_path+0x303/0x381
...
[ 8633.839848] RSP: 0018:ffffb04d407f7d00 EFLAGS: 00010286
[ 8633.839850] RAX: 0000000000000000 RBX: ffff9460b9897ee8 RCX: 00000000000000fe
[ 8633.839851] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
[ 8633.839852] RBP: ffff946076049850 R08: 0000000059263a83 R09: ffff9460840e4000
[ 8633.839853] R10: 0000000000000014 R11: 0000000000000000 R12: ffffb04d407f7dc0
[ 8633.839854] R13: ffffffffa4ce3240 R14: 0000000000000000 R15: ffff9460b7681f60
[ 8633.839857] FS: 00007fcac2e02700(0000) GS:ffff9460bdc00000(0000) knlGS:0000000000000000
[ 8633.839858] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8633.839859] CR2: 00007f27beb77e28 CR3: 0000000077734000 CR4: 00000000000006f0
[ 8633.839867] Call Trace:
[ 8633.839871] ip_route_output_key_hash_rcu+0x421/0x890
[ 8633.839873] ip_route_output_key_hash+0x5e/0x80
[ 8633.839876] ip_route_output_flow+0x1a/0x50
[ 8633.839878] __ip4_datagram_connect+0x154/0x310
[ 8633.839880] ip4_datagram_connect+0x28/0x40
[ 8633.839882] __sys_connect+0xd6/0x100
...
The WARN_ON is triggered in fib_select_default which is invoked when
there are multiple default routes. Update the function to use
fib_info_nhc and convert the nexthop checks to use fib_nh_common.
Add test case that covers the affected code path.
[0] https://github.com/FRRouting/frr/issues/6089
Fixes: 493ced1ac47c ("ipv4: Allow routes to use nexthop objects")
Signed-off-by: David Ahern <dsahern@gmail.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.
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.