ipv4: provide stronger user input validation in nl_fib_input()
authorEric Dumazet <edumazet@google.com>
Wed, 22 Mar 2017 02:22:28 +0000 (19:22 -0700)
committerDavid S. Miller <davem@davemloft.net>
Wed, 22 Mar 2017 21:15:49 +0000 (14:15 -0700)
commitc64c0b3cac4c5b8cb093727d2c19743ea3965c0b
treecf028128aa74adefd46b05428bcc82cb132c9f43
parent8c290e60fa2a51806159522331c9ed41252a8fb3
ipv4: provide stronger user input validation in nl_fib_input()

Alexander reported a KMSAN splat caused by reads of uninitialized
field (tb_id_in) from user provided struct fib_result_nl

It turns out nl_fib_input() sanity tests on user input is a bit
wrong :

User can pretend nlh->nlmsg_len is big enough, but provide
at sendmsg() time a too small buffer.

Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/fib_frontend.c