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    Subject[PATCH 4.20 053/117] mmc: meson-gx: Free irq in release() callback
    Date
    4.20-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Remi Pommarel <repk@triplefau.lt>

    commit bb364890323cca6e43f13e86d190ebf34a7d8cea upstream.

    Because the irq was requested through device managed resources API
    (devm_request_threaded_irq()) it was freed after meson_mmc_remove()
    completion, thus after mmc_free_host() has reclaimed meson_host memory.
    As this irq is IRQF_SHARED, while using CONFIG_DEBUG_SHIRQ, its handler
    get called by free_irq(). So meson_mmc_irq() was called after the
    meson_host memory reclamation and was using invalid memory.

    We ended up with the following scenario:
    device_release_driver()
    meson_mmc_remove()
    mmc_free_host() /* Freeing host memory */
    ...
    devres_release_all()
    devm_irq_release()
    __free_irq()
    meson_mmc_irq() /* Uses freed memory */

    To avoid this, the irq is released in meson_mmc_remove() and in
    mseon_mmc_probe() error path before mmc_free_host() gets called.

    Reported-by: Elie Roudninski <xademax@gmail.com>
    Signed-off-by: Remi Pommarel <repk@triplefau.lt>
    Cc: stable@vger.kernel.org
    Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/mmc/host/meson-gx-mmc.c | 18 +++++++++++-------
    1 file changed, 11 insertions(+), 7 deletions(-)

    --- a/drivers/mmc/host/meson-gx-mmc.c
    +++ b/drivers/mmc/host/meson-gx-mmc.c
    @@ -174,6 +174,8 @@ struct meson_host {
    struct sd_emmc_desc *descs;
    dma_addr_t descs_dma_addr;

    + int irq;
    +
    bool vqmmc_enabled;
    };

    @@ -1181,7 +1183,7 @@ static int meson_mmc_probe(struct platfo
    struct resource *res;
    struct meson_host *host;
    struct mmc_host *mmc;
    - int ret, irq;
    + int ret;

    mmc = mmc_alloc_host(sizeof(struct meson_host), &pdev->dev);
    if (!mmc)
    @@ -1228,8 +1230,8 @@ static int meson_mmc_probe(struct platfo
    goto free_host;
    }

    - irq = platform_get_irq(pdev, 0);
    - if (irq <= 0) {
    + host->irq = platform_get_irq(pdev, 0);
    + if (host->irq <= 0) {
    dev_err(&pdev->dev, "failed to get interrupt resource.\n");
    ret = -EINVAL;
    goto free_host;
    @@ -1283,9 +1285,8 @@ static int meson_mmc_probe(struct platfo
    writel(IRQ_CRC_ERR | IRQ_TIMEOUTS | IRQ_END_OF_CHAIN,
    host->regs + SD_EMMC_IRQ_EN);

    - ret = devm_request_threaded_irq(&pdev->dev, irq, meson_mmc_irq,
    - meson_mmc_irq_thread, IRQF_SHARED,
    - NULL, host);
    + ret = request_threaded_irq(host->irq, meson_mmc_irq,
    + meson_mmc_irq_thread, IRQF_SHARED, NULL, host);
    if (ret)
    goto err_init_clk;

    @@ -1303,7 +1304,7 @@ static int meson_mmc_probe(struct platfo
    if (host->bounce_buf == NULL) {
    dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n");
    ret = -ENOMEM;
    - goto err_init_clk;
    + goto err_free_irq;
    }

    host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
    @@ -1322,6 +1323,8 @@ static int meson_mmc_probe(struct platfo
    err_bounce_buf:
    dma_free_coherent(host->dev, host->bounce_buf_size,
    host->bounce_buf, host->bounce_dma_addr);
    +err_free_irq:
    + free_irq(host->irq, host);
    err_init_clk:
    clk_disable_unprepare(host->mmc_clk);
    err_core_clk:
    @@ -1339,6 +1342,7 @@ static int meson_mmc_remove(struct platf

    /* disable interrupts */
    writel(0, host->regs + SD_EMMC_IRQ_EN);
    + free_irq(host->irq, host);

    dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN,
    host->descs, host->descs_dma_addr);

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