From: "Toke Høiland-Jørgensen" <toke@redhat.com>
To: daniel@iogearbox.net, ast@fb.com
Cc: "Toke Høiland-Jørgensen" <toke@redhat.com>,
bpf@vger.kernel.org, netdev@vger.kernel.org,
"Tetsuo Handa" <penguin-kernel@i-love.sakura.ne.jp>
Subject: [PATCH bpf] xdp: Prevent overflow in devmap_hash cost calculation for 32-bit builds
Date: Thu, 17 Oct 2019 12:57:02 +0200 [thread overview]
Message-ID: <20191017105702.2807093-1-toke@redhat.com> (raw)
Tetsuo pointed out that without an explicit cast, the cost calculation for
devmap_hash type maps could overflow on 32-bit builds. This adds the
missing cast.
Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
kernel/bpf/devmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index a0a1153da5ae..e34fac6022eb 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -128,7 +128,7 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
if (!dtab->n_buckets) /* Overflow check */
return -EINVAL;
- cost += sizeof(struct hlist_head) * dtab->n_buckets;
+ cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
}
/* if map size is larger than memlock limit, reject it */
--
2.23.0
next reply other threads:[~2019-10-17 10:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 10:57 Toke Høiland-Jørgensen [this message]
2019-10-17 18:52 ` [PATCH bpf] xdp: Prevent overflow in devmap_hash cost calculation for 32-bit builds Jakub Kicinski
2019-10-18 9:15 ` Toke Høiland-Jørgensen
2019-10-18 17:19 ` Jakub Kicinski
2019-10-18 16:44 ` Yonghong Song
2019-10-18 23:25 ` Alexei Starovoitov
2019-10-18 23:31 ` Jakub Kicinski
2019-10-19 0:44 ` David Miller
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