From e55449e71aade362aa684bd3222974fed6e2d1c6 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 24 Apr 2019 10:36:06 -0700 Subject: [PATCH] ipv6: Initialize fib6_result in bpf_ipv6_fib_lookup fib6_result is not initialized in bpf_ipv6_fib_lookup and potentially passses garbage to the fib lookup which triggers a KASAN warning: [ 262.055450] ================================================================== [ 262.057640] BUG: KASAN: user-memory-access in fib6_rule_suppress+0x4b/0xce [ 262.059488] Read of size 8 at addr 00000a20000000b0 by task swapper/1/0 [ 262.061238] [ 262.061673] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.1.0-rc5+ #56 [ 262.063493] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014 [ 262.065593] Call Trace: [ 262.066277] [ 262.066848] dump_stack+0x7e/0xbb [ 262.067764] kasan_report+0x18b/0x1b5 [ 262.069921] __asan_load8+0x7f/0x81 [ 262.070879] fib6_rule_suppress+0x4b/0xce [ 262.071980] fib_rules_lookup+0x275/0x2cd [ 262.073090] fib6_lookup+0x119/0x218 [ 262.076457] bpf_ipv6_fib_lookup+0x39d/0x664 ... Initialize fib6_result to 0. Fixes: b1d40991506aa ("ipv6: Rename fib6_multipath_select and pass fib6_result") Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/core/filter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index fa8fb0548217..9d28e7e8a4cb 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4680,8 +4680,8 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params, { struct in6_addr *src = (struct in6_addr *) params->ipv6_src; struct in6_addr *dst = (struct in6_addr *) params->ipv6_dst; + struct fib6_result res = {}; struct neighbour *neigh; - struct fib6_result res; struct net_device *dev; struct inet6_dev *idev; struct flowi6 fl6; -- 2.30.2