When desc->len is equal to chunk_size, it is legal. But
xp_aligned_validate_desc() got "chunk_end" by desc->addr + desc->len
pointing to the next chunk during the check, which caused the check to
fail.
Related commit:
commit 2b43470add8c ("xsk: Introduce AF_XDP buffer allocation API")
commit 26062b185eee ("xsk: Explicitly inline functions and move
definitions")
This problem was first introduced in "bbff2f321a86". Later in
"2b43470add8c" this piece of code was moved into the new function
xp_aligned_validate_desc(). Later this function was moved into the file
xsk_queue.h in "26062b185eee".
Fixes: bbff2f321a86 ("xsk: new descriptor addressing scheme")
Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Acked-by: Magnus Karlsson <magnus.karlsson@xxxxxxxxx>
---
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 2823b7c3302d..40f359bf2044 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -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;
--
2.31.0
