From: Fan Wu Date: Sat, 18 Jul 2026 02:43:52 +0000 (+0000) Subject: wifi: brcmfmac: make release_scratchbuffers idempotent X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=538c51e9d124cf656f2dd0c0394a8545efc7102d;p=thirdparty%2Fkernel%2Flinux.git wifi: brcmfmac: make release_scratchbuffers idempotent brcmf_pcie_release_scratchbuffers() frees the shared.scratch and shared.ringupd DMA buffers with dma_free_coherent() but does not clear the pointers afterwards, unlike the sibling release_ringbuffers() which NULLs commonrings/flowrings/idxbuf on release. Both the bus_reset .reset callback (brcmf_pcie_reset) and brcmf_pcie_remove() call release_scratchbuffers. When reset teardown has run before removal, remove's own teardown would call dma_free_coherent() a second time on the already-freed DMA allocation. NULL the pointers after free, matching release_ringbuffers(), so a later release observes that the allocation has already been released. This patch makes repeated sequential release safe; the reset-work lifetime is handled separately by the following patch. This issue was found by an in-house static analysis tool. Fixes: 4684997d9eea ("brcmfmac: reset PCIe bus on a firmware crash") Cc: stable@vger.kernel.org Signed-off-by: Fan Wu Assisted-by: Codex:gpt-5.6 Acked-by: Arend van Spriel Link: https://patch.msgid.link/20260718024353.3147201-2-fanwu01@zju.edu.cn Signed-off-by: Johannes Berg --- diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c index 13662aa4b4ea..9f10b3fff9ff 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c @@ -1383,16 +1383,20 @@ fail: static void brcmf_pcie_release_scratchbuffers(struct brcmf_pciedev_info *devinfo) { - if (devinfo->shared.scratch) + if (devinfo->shared.scratch) { dma_free_coherent(&devinfo->pdev->dev, BRCMF_DMA_D2H_SCRATCH_BUF_LEN, devinfo->shared.scratch, devinfo->shared.scratch_dmahandle); - if (devinfo->shared.ringupd) + devinfo->shared.scratch = NULL; + } + if (devinfo->shared.ringupd) { dma_free_coherent(&devinfo->pdev->dev, BRCMF_DMA_D2H_RINGUPD_BUF_LEN, devinfo->shared.ringupd, devinfo->shared.ringupd_dmahandle); + devinfo->shared.ringupd = NULL; + } } static int brcmf_pcie_init_scratchbuffers(struct brcmf_pciedev_info *devinfo)