xsk: Fix unaligned descriptor validation

[ Upstream commit d769ccaf95 ]

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.
For example, descriptors in zero-copy mode that overrun the end of the
UMEM but not a page boundary are (incorrectly) considered valid. The
UMEM boundary 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: 2b43470add ("xsk: Introduce AF_XDP buffer allocation API")
Signed-off-by: Kal Conley <kal.conley@dectris.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230405235920.7305-2-kal.conley@dectris.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kal Conley 2023-04-06 01:59:18 +02:00 committed by Greg Kroah-Hartman
parent 8bc8e34e80
commit 3ee343914c
2 changed files with 3 additions and 7 deletions

View File

@ -175,13 +175,8 @@ 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)

View File

@ -161,6 +161,7 @@ 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;