xsk: Fix for xp_aligned_validate_desc() when len == chunk_size

When desc->len is equal to chunk_size, it is legal. But when the
xp_aligned_validate_desc() got chunk_end from desc->addr + desc->len
pointing to the next chunk during the check, it caused the check to
fail.

This problem was first introduced in bbff2f321a ("xsk: new descriptor
addressing scheme"). Later in 2b43470add ("xsk: Introduce AF_XDP buffer
allocation API") this piece of code was moved into the new function called
xp_aligned_validate_desc(). This function was then moved into xsk_queue.h
via 26062b185e ("xsk: Explicitly inline functions and move definitions").

Fixes: bbff2f321a ("xsk: new descriptor addressing scheme")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20210428094424.54435-1-xuanzhuo@linux.alibaba.com
This commit is contained in:
Xuan Zhuo 2021-04-28 17:44:24 +08:00 коммит произвёл Daniel Borkmann
Родитель 2a30f94406
Коммит ac31565c21
1 изменённых файлов: 3 добавлений и 4 удалений

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@ -128,13 +128,12 @@ static inline bool xskq_cons_read_addr_unchecked(struct xsk_queue *q, u64 *addr)
static inline bool xp_aligned_validate_desc(struct xsk_buff_pool *pool,
struct xdp_desc *desc)
{
u64 chunk, chunk_end;
u64 chunk;
chunk = xp_aligned_extract_addr(pool, desc->addr);
chunk_end = xp_aligned_extract_addr(pool, desc->addr + desc->len);
if (chunk != chunk_end)
if (desc->len > pool->chunk_size)
return false;
chunk = xp_aligned_extract_addr(pool, desc->addr);
if (chunk >= pool->addrs_cnt)
return false;