#include #include #include /** * memweight - count the total number of bits set in memory area * @ptr: pointer to the start of the area * @bytes: the size of the area */ size_t memweight(const void *ptr, size_t bytes) { size_t ret = 0; size_t longs; const unsigned char *bitmap = ptr; for (; bytes > 0 && ((unsigned long)bitmap) % sizeof(long); bytes--, bitmap++) ret += hweight8(*bitmap); longs = bytes / sizeof(long); if (longs) { BUG_ON(longs >= INT_MAX / BITS_PER_LONG); ret += bitmap_weight((unsigned long *)bitmap, longs * BITS_PER_LONG); bytes -= longs * sizeof(long); bitmap += longs * sizeof(long); } /* * The reason that this last loop is distinct from the preceding * bitmap_weight() call is to compute 1-bits in the last region smaller * than sizeof(long) properly on big-endian systems. */ for (; bytes > 0; bytes--, bitmap++) ret += hweight8(*bitmap); return ret; } EXPORT_SYMBOL(memweight); emaclite-cleanup'>emaclite-cleanup net-next plumbingsTobias Klauser
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authorDaniel Borkmann <daniel@iogearbox.net>2017-02-08 01:19:43 +0100
committerDavid S. Miller <davem@davemloft.net>2017-02-08 14:40:03 -0500
commitc502faf94153bd0fedc5389a936f728a659cc6ab (patch)
tree603e482c1467bc7d156623c9b83df0cee514d6aa
parent8ef9594764617e3fd4500205b080b53c45c14c4b (diff)
bpf, lpm: fix overflows in trie_alloc checks
Cap the maximum (total) value size and bail out if larger than KMALLOC_MAX_SIZE as otherwise it doesn't make any sense to proceed further, since we're guaranteed to fail to allocate elements anyway in lpm_trie_node_alloc(); likleyhood of failure is still high for large values, though, similarly as with htab case in non-prealloc. Next, make sure that cost vars are really u64 instead of size_t, so that we don't overflow on 32 bit and charge only tiny map.pages against memlock while allowing huge max_entries; cap also the max cost like we do with other map types. Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat
-rw-r--r--kernel/bpf/lpm_trie.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c