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author | Eric Dumazet <edumazet@google.com> | 2017-05-25 14:27:35 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-07 12:05:59 +0200 |
commit | 338f665acb4ba0b2c7656cc2487326497220168f (patch) | |
tree | 0fbfa975d486b03d73117a5318d46d33e653c29c /include/net/ip_fib.h | |
parent | 97f54575ff57da3f93f95006802a7892450c1898 (diff) | |
download | linux-stable-338f665acb4ba0b2c7656cc2487326497220168f.tar.gz linux-stable-338f665acb4ba0b2c7656cc2487326497220168f.tar.bz2 linux-stable-338f665acb4ba0b2c7656cc2487326497220168f.zip |
ipv4: add reference counting to metrics
[ Upstream commit 3fb07daff8e99243366a081e5129560734de4ada ]
Andrey Konovalov reported crashes in ipv4_mtu()
I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :
1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &
2) At the same time run following loop :
while :
do
ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done
Cong Wang attempted to add back rt->fi in commit
82486aa6f1b9 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.
Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)
I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.
Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.
Fixes: 2860583fe840 ("ipv4: Kill rt->fi")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/net/ip_fib.h')
-rw-r--r-- | include/net/ip_fib.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 3f98233388fb..bda1721e9622 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -112,11 +112,11 @@ struct fib_info { unsigned char fib_type; __be32 fib_prefsrc; u32 fib_priority; - u32 *fib_metrics; -#define fib_mtu fib_metrics[RTAX_MTU-1] -#define fib_window fib_metrics[RTAX_WINDOW-1] -#define fib_rtt fib_metrics[RTAX_RTT-1] -#define fib_advmss fib_metrics[RTAX_ADVMSS-1] + struct dst_metrics *fib_metrics; +#define fib_mtu fib_metrics->metrics[RTAX_MTU-1] +#define fib_window fib_metrics->metrics[RTAX_WINDOW-1] +#define fib_rtt fib_metrics->metrics[RTAX_RTT-1] +#define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] int fib_nhs; #ifdef CONFIG_IP_ROUTE_MULTIPATH int fib_weight; |