Make sure unaligned descriptors that straddle the end of the UMEM are
considered invalid. Currently, descriptor validation is broken for
zero-copy mode which only checks descriptors at page granularity.
Descriptors that cross the end of the UMEM but not a page boundary may
be therefore incorrectly considered valid. The check needs to happen
before the page boundary and contiguity checks in
xp_desc_crosses_non_contig_pg. Do this check in
xp_unaligned_validate_desc instead like xp_check_unaligned already does.
Fixes: 2b43470add8c ("xsk: Introduce AF_XDP buffer allocation API")
Signed-off-by: Kal Conley <kal.conley@xxxxxxxxxxx>
---
include/net/xsk_buff_pool.h | 9 ++-------
net/xdp/xsk_queue.h | 1 +
2 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index 3e952e569418..d318c769b445 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -180,13 +180,8 @@ static inline bool xp_desc_crosses_non_contig_pg(struct xsk_buff_pool *pool,
if (likely(!cross_pg))
return false;
- if (pool->dma_pages_cnt) {
- return !(pool->dma_pages[addr >> PAGE_SHIFT] &
- XSK_NEXT_PG_CONTIG_MASK);
- }
-
- /* skb path */
- return addr + len > pool->addrs_cnt;
+ return pool->dma_pages_cnt &&
+ !(pool->dma_pages[addr >> PAGE_SHIFT] & XSK_NEXT_PG_CONTIG_MASK);
}
static inline u64 xp_aligned_extract_addr(struct xsk_buff_pool *pool, u64 addr)
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index bfb2a7e50c26..66c6f57c9c44 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -162,6 +162,7 @@ static inline bool xp_unaligned_validate_desc(struct xsk_buff_pool *pool,
return false;
if (base_addr >= pool->addrs_cnt || addr >= pool->addrs_cnt ||
+ addr + desc->len > pool->addrs_cnt ||
xp_desc_crosses_non_contig_pg(pool, addr, desc->len))
return false;
--
2.39.2
