Re: [PATCH v2] ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule

From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 24 Sep 2019 16:01:28 +0200

Commit 7d9e5f422150 removed references from certain dsts, but accounting
for this never translated down into the fib6 suppression code. This bug
was triggered by WireGuard users who use wg-quick(8), which uses the
"suppress-prefix" directive to ip-rule(8) for routing all of their
internet traffic without routing loops. The test case added here
causes the reference underflow by causing packets to evaluate a suppress
rule.

Cc: stable@vger.kernel.org

Please don't CC: stable for networking fixes, I handle these manually as per
the netdev FAQ.

Fixes: 7d9e5f422150 ("ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

Applied and queued up for -stable, thanks.