This is a note to let you know that I've just added the patch titled
bpf: fix wrong exposure of map_flags into fdinfo for lpm
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: bpf-fix-wrong-exposure-of-map_flags-into-fdinfo-for-lpm.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Fri Mar 9 14:20:51 PST 2018
From: Daniel Borkmann daniel@iogearbox.net Date: Thu, 8 Mar 2018 16:17:32 +0100 Subject: bpf: fix wrong exposure of map_flags into fdinfo for lpm To: gregkh@linuxfoundation.org Cc: ast@kernel.org, daniel@iogearbox.net, stable@vger.kernel.org, "David S . Miller" davem@davemloft.net Message-ID: d0c41d2614afbe10501cc3d96d998952694bab7f.1520521792.git.daniel@iogearbox.net
From: Daniel Borkmann daniel@iogearbox.net
[ upstream commit a316338cb71a3260201490e615f2f6d5c0d8fb2c ]
trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via attr->map_flags, since it does not support preallocation yet. We check the flag, but we never copy the flag into trie->map.map_flags, which is later on exposed into fdinfo and used by loaders such as iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test whether a pinned map has the same spec as the one from the BPF obj file and if not, bails out, which is currently the case for lpm since it exposes always 0 as flags.
Also copy over flags in array_map_alloc() and stack_map_alloc(). They always have to be 0 right now, but we should make sure to not miss to copy them over at a later point in time when we add actual flags for them to use.
Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Reported-by: Jarno Rajahalme jarno@covalent.io Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Alexei Starovoitov ast@kernel.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/bpf/arraymap.c | 1 + kernel/bpf/stackmap.c | 1 + 2 files changed, 2 insertions(+)
--- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -107,6 +107,7 @@ static struct bpf_map *array_map_alloc(u array->map.key_size = attr->key_size; array->map.value_size = attr->value_size; array->map.max_entries = attr->max_entries; + array->map.map_flags = attr->map_flags; array->elem_size = elem_size;
if (!percpu) --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -88,6 +88,7 @@ static struct bpf_map *stack_map_alloc(u smap->map.key_size = attr->key_size; smap->map.value_size = value_size; smap->map.max_entries = attr->max_entries; + smap->map.map_flags = attr->map_flags; smap->n_buckets = n_buckets; smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
Patches currently in stable-queue which might be from daniel@iogearbox.net are
queue-4.9/bpf-fix-mlock-precharge-on-arraymaps.patch queue-4.9/bpf-x64-implement-retpoline-for-tail-call.patch queue-4.9/bpf-arm64-fix-out-of-bounds-access-in-tail-call.patch queue-4.9/bpf-fix-wrong-exposure-of-map_flags-into-fdinfo-for-lpm.patch queue-4.9/bpf-ppc64-fix-out-of-bounds-access-in-tail-call.patch queue-4.9/bpf-add-schedule-points-in-percpu-arrays-management.patch