bpf: Do not copy spin lock field from user in bpf_selem_alloc

bpf_selem_alloc function is used by inode_storage, sk_storage and
task_storage maps to set map value, for these map types, there may
be a spin lock in the map value, so if we use memcpy to copy the whole
map value from user, the spin lock field may be initialized incorrectly.

Since the spin lock field is zeroed by kzalloc, call copy_map_value
instead of memcpy to skip copying the spin lock field to fix it.

Fixes: 6ac99e8f23d4 ("bpf: Introduce bpf sk local storage")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20221114134720.1057939-2-xukuohai@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index 802fc15b0d73cd9ecfe5bf66f7f4d5a8576006f7..f27fa5ba7d722c12869e45b1340579fd46247139 100644 (file)
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -74,7 +74,7 @@ bpf_selem_alloc(struct bpf_local_storage_map *smap, void *owner,
                                gfp_flags | __GFP_NOWARN);
        if (selem) {
                if (value)
-                       memcpy(SDATA(selem)->data, value, smap->map.value_size);
+                       copy_map_value(&smap->map, SDATA(selem)->data, value);
                return selem;
        }