On 07/16/2018 05:55 PM, LABBE Corentin wrote:
On Mon, Jul 16, 2018 at 04:11:44PM +0300, Mikko Perttunen wrote:Hello, the recently applied "ata: ahci_platform: convert kcalloc to devm_kcalloc" seems to be causing boot failures on Tegra124 Jetson TK1. The patch is as follows: diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c index be9f54423a9b..fe8939e161ea 100644 --- a/drivers/ata/libahci_platform.c +++ b/drivers/ata/libahci_platform.c @@ -271,8 +271,6 @@ static void ahci_platform_put_resources(struct device *dev, void *res) for (c = 0; c < hpriv->nports; c++) if (hpriv->target_pwrs && hpriv->target_pwrs[c]) regulator_put(hpriv->target_pwrs[c]); - - kfree(hpriv->target_pwrs); } static int ahci_platform_get_phy(struct ahci_host_priv *hpriv, u32 port, @@ -408,7 +406,7 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev) rc = -ENOMEM; goto err_out; } - hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL); + hpriv->target_pwrs = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->target_pwrs), GFP_KERNEL); if (!hpriv->target_pwrs) { rc = -ENOMEM; goto err_out; However, this is not valid, as it will cause hpriv->target_pwrs to be freed before ahci_platform_put_resources is called. With the older code, the free happened intentionally only after the regulator_put calls were done.Hello I am surprised, since I have tested all my AHCI patch on a Tegra124 Jetson TK1. Could you print the boot crash ?
I don't have the crash log in front of me now (can get it to you tomorrow), but basically it was ahci_platform_put_resources calling eventually _regulator_put which was dereferencing 0x6b6b6bbf, quite clearly an offset of 0x6b6b6b6b which is the use-after-free poison.
It actually only happens on tegra_defconfig -- I assume there's some different dependency situation that doesn't happen on multi_v7_defconfig, that causes ahci-tegra to defer probe, causing the error path to be triggered.
Thanks, Mikko
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