From d401772a9e18e837631450844f835229354528a4 Mon Sep 17 00:00:00 2001 From: Yousef Alhouseen Date: Tue, 30 Jun 2026 12:49:23 +0200 Subject: [PATCH] misc: genwqe: handle a first DMA address of zero genwqe_setup_sgl() uses zero as the initial previous DMA address. DMA address zero is valid, so a first entry at that address enters the merge path before last_s has been assigned and dereferences NULL. Only merge adjacent mappings after an SGL data entry has been created. Signed-off-by: Yousef Alhouseen Link: https://patch.msgid.link/20260630104923.53827-1-alhouseenyousef@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/genwqe/card_utils.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c index a2c4a9b4f871..e3b5fb337182 100644 --- a/drivers/misc/genwqe/card_utils.c +++ b/drivers/misc/genwqe/card_utils.c @@ -413,7 +413,7 @@ int genwqe_setup_sgl(struct genwqe_dev *cd, struct genwqe_sgl *sgl, size -= size_to_map; map_offs = 0; - if (prev_daddr == daddr) { + if (last_s && prev_daddr == daddr) { u32 prev_len = be32_to_cpu(last_s->len); /* pr_info("daddr combining: "