From f3eceaed9edd7c0e0d9fb057613131f92973626f Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 27 Jan 2023 14:38:54 -0800 Subject: [PATCH] net: ethernet: mtk_eth_soc: Avoid truncating allocation There doesn't appear to be a reason to truncate the allocation used for flow_info, so do a full allocation and remove the unused empty struct. GCC does not like having a reference to an object that has been partially allocated, as bounds checking may become impossible when such an object is passed to other code. Seen with GCC 13: ../drivers/net/ethernet/mediatek/mtk_ppe.c: In function 'mtk_foe_entry_commit_subflow': ../drivers/net/ethernet/mediatek/mtk_ppe.c:623:18: warning: array subscript 'struct mtk_flow_entry[0]' is partly outside array bounds of 'unsigned char[48]' [-Warray-bounds=] 623 | flow_info->l2_data.base_flow = entry; | ^~ Cc: Felix Fietkau Cc: John Crispin Cc: Sean Wang Cc: Mark Lee Cc: Lorenzo Bianconi Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Matthias Brugger Cc: netdev@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mediatek@lists.infradead.org Signed-off-by: Kees Cook Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230127223853.never.014-kees@kernel.org Signed-off-by: Paolo Abeni --- drivers/net/ethernet/mediatek/mtk_ppe.c | 3 +-- drivers/net/ethernet/mediatek/mtk_ppe.h | 1 - 2 files changed, 1 insertion(+), 3 deletions(-) --- a/drivers/net/ethernet/mediatek/mtk_ppe.c +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c @@ -601,8 +601,7 @@ mtk_foe_entry_commit_subflow(struct mtk_ u32 ib1_mask = mtk_get_ib1_pkt_type_mask(ppe->eth) | MTK_FOE_IB1_UDP; int type; - flow_info = kzalloc(offsetof(struct mtk_flow_entry, l2_data.end), - GFP_ATOMIC); + flow_info = kzalloc(sizeof(*flow_info), GFP_ATOMIC); if (!flow_info) return; --- a/drivers/net/ethernet/mediatek/mtk_ppe.h +++ b/drivers/net/ethernet/mediatek/mtk_ppe.h @@ -277,7 +277,6 @@ struct mtk_flow_entry { struct { struct mtk_flow_entry *base_flow; struct hlist_node list; - struct {} end; } l2_data; }; struct rhash_head node;