From 5deee88b8a680a25abd4e20e7f822f700c4924fc Mon Sep 17 00:00:00 2001 From: Chen Ridong Date: Tue, 29 Oct 2024 08:28:45 +0000 Subject: [PATCH] dmaengine: at_xdmac: avoid null_prt_deref in at_xdmac_prep_dma_memset BugLink: https://bugs.launchpad.net/bugs/2103869 commit c43ec96e8d34399bd9dab2f2dc316b904892133f upstream. The at_xdmac_memset_create_desc may return NULL, which will lead to a null pointer dereference. For example, the len input is error, or the atchan->free_descs_list is empty and memory is exhausted. Therefore, add check to avoid this. Fixes: b206d9a23ac7 ("dmaengine: xdmac: Add memset support") Signed-off-by: Chen Ridong Link: https://lore.kernel.org/r/20241029082845.1185380-1-chenridong@huaweicloud.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman CVE-2024-56767 Signed-off-by: Manuel Diewald Signed-off-by: Mehmet Basaran --- drivers/dma/at_xdmac.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 299396121e6d..e847ad66dc0b 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1363,6 +1363,8 @@ at_xdmac_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, return NULL; desc = at_xdmac_memset_create_desc(chan, atchan, dest, len, value); + if (!desc) + return NULL; list_add_tail(&desc->desc_node, &desc->descs_list); desc->tx_dma_desc.cookie = -EBUSY;