Xin Long
1c87e79a00
ipv6: make ip6_create_rt_rcu return ip6_null_entry instead of NULL
Jianlin reported a crash: [ 381.484332] BUG: unable to handle kernel NULL pointer dereference at 0000000000000068 [ 381.619802] RIP: 0010:fib6_rule_lookup+0xa3/0x160 [ 382.009615] Call Trace: [ 382.020762] <IRQ> [ 382.030174] ip6_route_redirect.isra.52+0xc9/0xf0 [ 382.050984] ip6_redirect+0xb6/0xf0 [ 382.066731] icmpv6_notify+0xca/0x190 [ 382.083185] ndisc_redirect_rcv+0x10f/0x160 [ 382.102569] ndisc_rcv+0xfb/0x100 [ 382.117725] icmpv6_rcv+0x3f2/0x520 [ 382.133637] ip6_input_finish+0xbf/0x460 [ 382.151634] ip6_input+0x3b/0xb0 [ 382.166097] ipv6_rcv+0x378/0x4e0 It was caused by the lookup function __ip6_route_redirect() returns NULL in fib6_rule_lookup() when ip6_create_rt_rcu() returns NULL. So we fix it by simply making ip6_create_rt_rcu() return ip6_null_entry instead of NULL. v1->v2: - move down 'fallback:' to make it more readable. Fixes: e873e4b9cc7e ("ipv6: use fib6_info_hold_safe() when necessary") Reported-by: Jianlin Shi <jishi@redhat.com> Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Acked-by: Wei Wang <weiwan@google.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.
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