[PATCH v2] bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc
From: Bui Quang Minh <hidden>
Date: 2021-06-13 14:37:24
Also in:
lkml, netdev
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [l7 framework] (sockmap), networking [general], networking [sockets], the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, John Fastabend, Jakub Sitnicki, Jiayuan Chen, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds, David S. Miller, Jesper Dangaard Brouer
In 32-bit architecture, the result of sizeof() is a 32-bit integer so
the expression becomes the multiplication between 2 32-bit integer which
can potentially leads to integer overflow. As a result,
bpf_map_area_alloc() allocates less memory than needed.
Fix this by casting 1 operand to u64.
Fixes: 0d2c4f964050 ("bpf: Eliminate rlimit-based memory accounting for sockmap
and sockhash maps")
Fixes: 99c51064fb06 ("devmap: Use bpf_map_area_alloc() for allocating hash
buckets")
Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references")
Signed-off-by: Bui Quang Minh <redacted>
---
v2: Add Fixes tag
kernel/bpf/devmap.c | 4 ++--
net/core/sock_map.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index aa516472ce46..3b45c23286c0 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c@@ -92,7 +92,7 @@ static struct hlist_head *dev_map_create_hash(unsigned int entries, int i; struct hlist_head *hash; - hash = bpf_map_area_alloc(entries * sizeof(*hash), numa_node); + hash = bpf_map_area_alloc((u64) entries * sizeof(*hash), numa_node); if (hash != NULL) for (i = 0; i < entries; i++) INIT_HLIST_HEAD(&hash[i]);
@@ -143,7 +143,7 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) spin_lock_init(&dtab->index_lock); } else { - dtab->netdev_map = bpf_map_area_alloc(dtab->map.max_entries * + dtab->netdev_map = bpf_map_area_alloc((u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *), dtab->map.numa_node); if (!dtab->netdev_map)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 6f1b82b8ad49..60decd6420ca 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c@@ -48,7 +48,7 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr) bpf_map_init_from_attr(&stab->map, attr); raw_spin_lock_init(&stab->lock); - stab->sks = bpf_map_area_alloc(stab->map.max_entries * + stab->sks = bpf_map_area_alloc((u64) stab->map.max_entries * sizeof(struct sock *), stab->map.numa_node); if (!stab->sks) {
--
2.25.1