From: Xuan Zhuo xuanzhuo@linux.alibaba.com
[ Upstream commit ac31565c21937eee9117e43c9cd34f557f6f1cb8 ]
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 bbff2f321a86 ("xsk: new descriptor addressing scheme"). Later in 2b43470add8c ("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 26062b185eee ("xsk: Explicitly inline functions and move definitions").
Fixes: bbff2f321a86 ("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.co... Signed-off-by: Sasha Levin sashal@kernel.org --- net/xdp/xsk_queue.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h index ef6de0fb4e31..be9fd5a72011 100644 --- a/net/xdp/xsk_queue.h +++ b/net/xdp/xsk_queue.h @@ -126,13 +126,12 @@ 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;