devm_blk_crypto_profile_init() registers a cleanup handler to run when
the associated (platform-) device is being released. For UFS, the
crypto private data and pointers are stored as part of the ufs_hba's
data structure 'struct ufs_hba::crypto_profile'. This structure is
allocated as part of the underlying ufshcd and therefore Scsi_host
allocation.
During driver release or during error handling in ufshcd_pltfrm_init(),
this structure is released as part of ufshcd_dealloc_host() before the
(platform-) device associated with the crypto call above is released.
Once this device is released, the crypto cleanup code will run, using
the just-released 'struct ufs_hba::crypto_profile'. This causes a
use-after-free situation:
Call trace:
kfree+0x60/0x2d8 (P)
kvfree+0x44/0x60
blk_crypto_profile_destroy_callback+0x28/0x70
devm_action_release+0x1c/0x30
release_nodes+0x6c/0x108
devres_release_all+0x98/0x100
device_unbind_cleanup+0x20/0x70
really_probe+0x218/0x2d0
In other words, the initialisation code flow is:
platform-device probe
ufshcd_pltfrm_init()
ufshcd_alloc_host()
scsi_host_alloc()
allocation of struct ufs_hba
creation of scsi-host devices
devm_blk_crypto_profile_init()
devm registration of cleanup handler using platform-device
and during error handling of ufshcd_pltfrm_init() or during driver
removal:
ufshcd_dealloc_host()
scsi_host_put()
put_device(scsi-host)
release of struct ufs_hba
put_device(platform-device)
crypto cleanup handler
To fix this use-after free, change ufshcd_alloc_host() to register a
devres action to automatically cleanup the underlying SCSI device on
ufshcd destruction, without requiring explicit calls to
ufshcd_dealloc_host(). This way:
* the crypto profile and all other ufs_hba-owned resources are
destroyed before SCSI (as they've been registered after)
* a memleak is plugged in tc-dwc-g210-pci.c remove() as a
side-effect
* EXPORT_SYMBOL_GPL(ufshcd_dealloc_host) can be removed fully as
it's not needed anymore
* no future drivers using ufshcd_alloc_host() could ever forget
adding the cleanup
Fixes: cb77cb5abe1f ("blk-crypto: rename blk_keyslot_manager to blk_crypto_profile")
Fixes: d76d9d7d1009 ("scsi: ufs: use devm_blk_ksm_init()")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: André Draszik <andre.draszik@xxxxxxxxxx>
---
Changes in v4:
- add a kdoc note to ufshcd_alloc_host() to state why there is no
ufshcd_dealloc_host() (Mani)
- use return err, without goto (Mani)
- drop register dump and abort info from commit message (Mani)
- Link to v3: https://lore.kernel.org/r/20250116-ufshcd-fix-v3-1-6a83004ea85c@xxxxxxxxxx
Changes in v3:
- rename devres action handler to ufshcd_devres_release() (Bart)
- Link to v2: https://lore.kernel.org/r/20250114-ufshcd-fix-v2-1-2dc627590a4a@xxxxxxxxxx
Changes in v2:
- completely new approach using devres action for Scsi_host cleanup, to
ensure ordering
- add Fixes: and CC: stable tags (Eric)
- Link to v1: https://lore.kernel.org/r/20250113-ufshcd-fix-v1-1-ca63d1d4bd55@xxxxxxxxxx
---
In my case, as per above trace I initially encountered an error in
ufshcd_verify_dev_init(), which made me notice this problem both during
error handling and release. For reproducing, it'd be possible to change
that function to just return an error, or rmmod the platform glue
driver.
Other approaches for solving this issue I see are the following, but I
believe this one here is the cleanest:
* turn 'struct ufs_hba::crypto_profile' into a dynamically allocated
pointer, in which case it doesn't matter if cleanup runs after
scsi_host_put()
* add an explicit devm_blk_crypto_profile_deinit() to be called by API
users when necessary, e.g. before ufshcd_dealloc_host() in this case
* register the crypto cleanup handler against the scsi-host device
instead, like in v1 of this patch
---
drivers/ufs/core/ufshcd.c | 31 +++++++++++++++++++++----------
drivers/ufs/host/ufshcd-pci.c | 2 --
drivers/ufs/host/ufshcd-pltfrm.c | 28 +++++++++-------------------
include/ufs/ufshcd.h | 1 -
4 files changed, 30 insertions(+), 32 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 43ddae7318cb..4328f769a7c8 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -10279,16 +10279,6 @@ int ufshcd_system_thaw(struct device *dev)
EXPORT_SYMBOL_GPL(ufshcd_system_thaw);
#endif /* CONFIG_PM_SLEEP */
-/**
- * ufshcd_dealloc_host - deallocate Host Bus Adapter (HBA)
- * @hba: pointer to Host Bus Adapter (HBA)
- */
-void ufshcd_dealloc_host(struct ufs_hba *hba)
-{
- scsi_host_put(hba->host);
-}
-EXPORT_SYMBOL_GPL(ufshcd_dealloc_host);
-
/**
* ufshcd_set_dma_mask - Set dma mask based on the controller
* addressing capability
@@ -10307,12 +10297,26 @@ static int ufshcd_set_dma_mask(struct ufs_hba *hba)
return dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(32));
}
+/**
+ * ufshcd_devres_release - devres cleanup handler, invoked during release of
+ * hba->dev
+ * @host: pointer to SCSI host
+ */
+static void ufshcd_devres_release(void *host)
+{
+ scsi_host_put(host);
+}
+
/**
* ufshcd_alloc_host - allocate Host Bus Adapter (HBA)
* @dev: pointer to device handle
* @hba_handle: driver private handle
*
* Return: 0 on success, non-zero value on failure.
+ *
+ * NOTE: There is no corresponding ufshcd_dealloc_host() because this function
+ * keeps track of its allocations using devres and deallocates everything on
+ * device removal automatically.
*/
int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle)
{
@@ -10334,6 +10338,13 @@ int ufshcd_alloc_host(struct device *dev, struct ufs_hba **hba_handle)
err = -ENOMEM;
goto out_error;
}
+
+ err = devm_add_action_or_reset(dev, ufshcd_devres_release,
+ host);
+ if (err)
+ return dev_err_probe(dev, err,
+ "failed to add ufshcd dealloc action\n");
+
host->nr_maps = HCTX_TYPE_POLL + 1;
hba = shost_priv(host);
hba->host = host;
diff --git a/drivers/ufs/host/ufshcd-pci.c b/drivers/ufs/host/ufshcd-pci.c
index ea39c5d5b8cf..9cfcaad23cf9 100644
--- a/drivers/ufs/host/ufshcd-pci.c
+++ b/drivers/ufs/host/ufshcd-pci.c
@@ -562,7 +562,6 @@ static void ufshcd_pci_remove(struct pci_dev *pdev)
pm_runtime_forbid(&pdev->dev);
pm_runtime_get_noresume(&pdev->dev);
ufshcd_remove(hba);
- ufshcd_dealloc_host(hba);
}
/**
@@ -605,7 +604,6 @@ ufshcd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
err = ufshcd_init(hba, mmio_base, pdev->irq);
if (err) {
dev_err(&pdev->dev, "Initialization failed\n");
- ufshcd_dealloc_host(hba);
return err;
}
diff --git a/drivers/ufs/host/ufshcd-pltfrm.c b/drivers/ufs/host/ufshcd-pltfrm.c
index 505572d4fa87..ffe5d1d2b215 100644
--- a/drivers/ufs/host/ufshcd-pltfrm.c
+++ b/drivers/ufs/host/ufshcd-pltfrm.c
@@ -465,21 +465,17 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
struct device *dev = &pdev->dev;
mmio_base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(mmio_base)) {
- err = PTR_ERR(mmio_base);
- goto out;
- }
+ if (IS_ERR(mmio_base))
+ return PTR_ERR(mmio_base);
irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- err = irq;
- goto out;
- }
+ if (irq < 0)
+ return irq;
err = ufshcd_alloc_host(dev, &hba);
if (err) {
dev_err(dev, "Allocation failed\n");
- goto out;
+ return err;
}
hba->vops = vops;
@@ -488,13 +484,13 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
if (err) {
dev_err(dev, "%s: clock parse failed %d\n",
__func__, err);
- goto dealloc_host;
+ return err;
}
err = ufshcd_parse_regulator_info(hba);
if (err) {
dev_err(dev, "%s: regulator init failed %d\n",
__func__, err);
- goto dealloc_host;
+ return err;
}
ufshcd_init_lanes_per_dir(hba);
@@ -502,25 +498,20 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
err = ufshcd_parse_operating_points(hba);
if (err) {
dev_err(dev, "%s: OPP parse failed %d\n", __func__, err);
- goto dealloc_host;
+ return err;
}
err = ufshcd_init(hba, mmio_base, irq);
if (err) {
dev_err_probe(dev, err, "Initialization failed with error %d\n",
err);
- goto dealloc_host;
+ return err;
}
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
return 0;
-
-dealloc_host:
- ufshcd_dealloc_host(hba);
-out:
- return err;
}
EXPORT_SYMBOL_GPL(ufshcd_pltfrm_init);
@@ -534,7 +525,6 @@ void ufshcd_pltfrm_remove(struct platform_device *pdev)
pm_runtime_get_sync(&pdev->dev);
ufshcd_remove(hba);
- ufshcd_dealloc_host(hba);
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
}
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index da0fa5c65081..58eb6e897827 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1311,7 +1311,6 @@ static inline void ufshcd_rmwl(struct ufs_hba *hba, u32 mask, u32 val, u32 reg)
void ufshcd_enable_irq(struct ufs_hba *hba);
void ufshcd_disable_irq(struct ufs_hba *hba);
int ufshcd_alloc_host(struct device *, struct ufs_hba **);
-void ufshcd_dealloc_host(struct ufs_hba *);
int ufshcd_hba_enable(struct ufs_hba *hba);
int ufshcd_init(struct ufs_hba *, void __iomem *, unsigned int);
int ufshcd_link_recovery(struct ufs_hba *hba);
---
base-commit: 4e16367cfe0ce395f29d0482b78970cce8e1db73
change-id: 20250113-ufshcd-fix-52409f2d32ff
Best regards,
--
André Draszik <andre.draszik@xxxxxxxxxx>
