From: Wei Fang Date: Wed, 20 May 2026 06:44:18 +0000 (+0800) Subject: net: enetc: fix DMA write to freed memory in enetc_msg_free_mbx() X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=adb4599979cd00d5d426f26cf78b65264217e35b;p=thirdparty%2Fkernel%2Flinux.git net: enetc: fix DMA write to freed memory in enetc_msg_free_mbx() The teardown sequence in enetc_msg_psi_free() frees the DMA buffer before clearing the device's DMA address registers. If a VF sends a message or a pending DMA transfer completes within this window, the hardware will perform a DMA write into the kernel memory that has already been returned to the allocator. The result is silent memory corruption that can affect arbitrary kernel data structures. Therefore, clear the DMA address registers before the DMA buffer is freed. Fixes: beb74ac878c8 ("enetc: Add vf to pf messaging support") Signed-off-by: Wei Fang Reviewed-by: Harshitha Ramamurthy Link: https://patch.msgid.link/20260520064421.91569-7-wei.fang@nxp.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/freescale/enetc/enetc_msg.c b/drivers/net/ethernet/freescale/enetc/enetc_msg.c index 40d22ebe9224..b4d7457097e6 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_msg.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_msg.c @@ -96,12 +96,12 @@ static void enetc_msg_free_mbx(struct enetc_si *si, int idx) struct enetc_hw *hw = &si->hw; struct enetc_msg_swbd *msg; + enetc_wr(hw, ENETC_PSIVMSGRCVAR0(idx), 0); + enetc_wr(hw, ENETC_PSIVMSGRCVAR1(idx), 0); + msg = &pf->rxmsg[idx]; dma_free_coherent(&si->pdev->dev, msg->size, msg->vaddr, msg->dma); memset(msg, 0, sizeof(*msg)); - - enetc_wr(hw, ENETC_PSIVMSGRCVAR0(idx), 0); - enetc_wr(hw, ENETC_PSIVMSGRCVAR1(idx), 0); } int enetc_msg_psi_init(struct enetc_pf *pf)