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authorStanislav Fomichev <sdf@fomichev.me>2024-07-13 04:52:51 +0300
committerDaniel Borkmann <daniel@iogearbox.net>2024-07-25 12:57:27 +0300
commitd5e726d9143c5624135f5dc9e4069799adeef734 (patch)
treed24f61de8cd5af48ecedeecac656669eb4a8019f /net
parentfa5ef655615a01533035c6139248c5b33aa27028 (diff)
downloadlinux-d5e726d9143c5624135f5dc9e4069799adeef734.tar.xz
xsk: Require XDP_UMEM_TX_METADATA_LEN to actuate tx_metadata_len
Julian reports that commit 341ac980eab9 ("xsk: Support tx_metadata_len") can break existing use cases which don't zero-initialize xdp_umem_reg padding. Introduce new XDP_UMEM_TX_METADATA_LEN to make sure we interpret the padding as tx_metadata_len only when being explicitly asked. Fixes: 341ac980eab9 ("xsk: Support tx_metadata_len") Reported-by: Julian Schindel <mail@arctic-alpaca.de> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/bpf/20240713015253.121248-2-sdf@fomichev.me
Diffstat (limited to 'net')
-rw-r--r--net/xdp/xdp_umem.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index caa340134b0e..9f76ca591d54 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -151,6 +151,7 @@ static int xdp_umem_account_pages(struct xdp_umem *umem)
#define XDP_UMEM_FLAGS_VALID ( \
XDP_UMEM_UNALIGNED_CHUNK_FLAG | \
XDP_UMEM_TX_SW_CSUM | \
+ XDP_UMEM_TX_METADATA_LEN | \
0)
static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
@@ -204,8 +205,11 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
if (headroom >= chunk_size - XDP_PACKET_HEADROOM)
return -EINVAL;
- if (mr->tx_metadata_len >= 256 || mr->tx_metadata_len % 8)
- return -EINVAL;
+ if (mr->flags & XDP_UMEM_TX_METADATA_LEN) {
+ if (mr->tx_metadata_len >= 256 || mr->tx_metadata_len % 8)
+ return -EINVAL;
+ umem->tx_metadata_len = mr->tx_metadata_len;
+ }
umem->size = size;
umem->headroom = headroom;
@@ -215,7 +219,6 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
umem->pgs = NULL;
umem->user = NULL;
umem->flags = mr->flags;
- umem->tx_metadata_len = mr->tx_metadata_len;
INIT_LIST_HEAD(&umem->xsk_dma_list);
refcount_set(&umem->users, 1);