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| author | Teng Qin | 2017-04-25 04:00:37 +0200 |
|---|---|---|
| committer | David S. Miller | 2017-04-25 17:57:45 +0200 |
| commit | 8fe45924387be6b5c1be59a7eb330790c61d5d10 (patch) | |
| tree | 1879f4fd4d14907155b1ebb2fd85ff26aa89ebbe /kernel/bpf/syscall.c | |
| parent | selftests/net: Fix broken test case in psock_fanout (diff) | |
| download | kernel-qcow2-linux-8fe45924387be6b5c1be59a7eb330790c61d5d10.tar.gz kernel-qcow2-linux-8fe45924387be6b5c1be59a7eb330790c61d5d10.tar.xz kernel-qcow2-linux-8fe45924387be6b5c1be59a7eb330790c61d5d10.zip | |
bpf: map_get_next_key to return first key on NULL
When iterating through a map, we need to find a key that does not exist
in the map so map_get_next_key will give us the first key of the map.
This often requires a lot of guessing in production systems.
This patch makes map_get_next_key return the first key when the key
pointer in the parameter is NULL.
Signed-off-by: Teng Qin <qinteng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b89288e2b589..13642c73dca0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -536,14 +536,18 @@ static int map_get_next_key(union bpf_attr *attr) if (IS_ERR(map)) return PTR_ERR(map); - err = -ENOMEM; - key = kmalloc(map->key_size, GFP_USER); - if (!key) - goto err_put; - - err = -EFAULT; - if (copy_from_user(key, ukey, map->key_size) != 0) - goto free_key; + if (ukey) { + err = -ENOMEM; + key = kmalloc(map->key_size, GFP_USER); + if (!key) + goto err_put; + + err = -EFAULT; + if (copy_from_user(key, ukey, map->key_size) != 0) + goto free_key; + } else { + key = NULL; + } err = -ENOMEM; next_key = kmalloc(map->key_size, GFP_USER); |