From ba6b8de423f8d0dee48d6030288ed81c03ddf9f0 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Mon, 23 Apr 2018 15:39:23 -0700 Subject: bpf: sockmap, map_release does not hold refcnt for pinned maps Relying on map_release hook to decrement the reference counts when a map is removed only works if the map is not being pinned. In the pinned case the ref is decremented immediately and the BPF programs released. After this BPF programs may not be in-use which is not what the user would expect. This patch moves the release logic into bpf_map_put_uref() and brings sockmap in-line with how a similar case is handled in prog array maps. Fixes: 3d9e952697de ("bpf: sockmap, fix leaking maps with attached but not detached progs") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann --- kernel/bpf/syscall.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4ca46df19c9a..ebfe9f29dae8 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -257,8 +257,8 @@ static void bpf_map_free_deferred(struct work_struct *work) static void bpf_map_put_uref(struct bpf_map *map) { if (atomic_dec_and_test(&map->usercnt)) { - if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) - bpf_fd_array_map_clear(map); + if (map->ops->map_release_uref) + map->ops->map_release_uref(map); } } -- cgit v1.2.3 From 9ef09e35e521bf0df5325cc9cffa726a8f5f3c1b Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 3 May 2018 17:04:59 +0100 Subject: bpf: fix possible spectre-v1 in find_and_alloc_map() It's possible for userspace to control attr->map_type. Sanitize it when using it as an array index to prevent an out-of-bounds value being used under speculation. Found by smatch. Signed-off-by: Mark Rutland Cc: Alexei Starovoitov Cc: Dan Carpenter Cc: Daniel Borkmann Cc: Peter Zijlstra Cc: netdev@vger.kernel.org Acked-by: David S. Miller Signed-off-by: Daniel Borkmann --- kernel/bpf/syscall.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ebfe9f29dae8..8f434485abd2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -26,6 +26,7 @@ #include #include #include +#include #define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \ (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \ @@ -102,12 +103,14 @@ const struct bpf_map_ops bpf_map_offload_ops = { static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) { const struct bpf_map_ops *ops; + u32 type = attr->map_type; struct bpf_map *map; int err; - if (attr->map_type >= ARRAY_SIZE(bpf_map_types)) + if (type >= ARRAY_SIZE(bpf_map_types)) return ERR_PTR(-EINVAL); - ops = bpf_map_types[attr->map_type]; + type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types)); + ops = bpf_map_types[type]; if (!ops) return ERR_PTR(-EINVAL); @@ -122,7 +125,7 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) if (IS_ERR(map)) return map; map->ops = ops; - map->map_type = attr->map_type; + map->map_type = type; return map; } -- cgit v1.2.3 From d0f1a451e33d9ca834422622da30aa68daade56b Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 4 May 2018 02:13:57 +0200 Subject: bpf: use array_index_nospec in find_prog_type Commit 9ef09e35e521 ("bpf: fix possible spectre-v1 in find_and_alloc_map()") converted find_and_alloc_map() over to use array_index_nospec() to sanitize map type that user space passes on map creation, and this patch does an analogous conversion for progs in find_prog_type() as it's also passed from user space when loading progs as attr->prog_type. Signed-off-by: Daniel Borkmann Cc: Mark Rutland Signed-off-by: Alexei Starovoitov --- kernel/bpf/syscall.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'kernel/bpf/syscall.c') diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 8f434485abd2..016ef9025827 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -874,11 +874,17 @@ static const struct bpf_prog_ops * const bpf_prog_types[] = { static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) { - if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type]) + const struct bpf_prog_ops *ops; + + if (type >= ARRAY_SIZE(bpf_prog_types)) + return -EINVAL; + type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types)); + ops = bpf_prog_types[type]; + if (!ops) return -EINVAL; if (!bpf_prog_is_dev_bound(prog->aux)) - prog->aux->ops = bpf_prog_types[type]; + prog->aux->ops = ops; else prog->aux->ops = &bpf_offload_prog_ops; prog->type = type; -- cgit v1.2.3