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 ufshd 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:
exynos-ufshc 14700000.ufs: ufshcd_pltfrm_init() failed -11 exynos-ufshc 14700000.ufs: probe with driver exynos-ufshc failed with error -11 Unable to handle kernel paging request at virtual address 01adafad6dadad88 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [01adafad6dadad88] address between user and kernel address ranges Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.13.0-rc5-next-20250106+ #70 Tainted: [W]=WARN Hardware name: Oriole (DT) pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kfree+0x60/0x2d8 lr : kvfree+0x44/0x60 sp : ffff80008009ba80 x29: ffff80008009ba90 x28: 0000000000000000 x27: ffffbcc6591e0130 x26: ffffbcc659309960 x25: ffffbcc658f89c50 x24: ffffbcc659539d80 x23: ffff22e000940040 x22: ffff22e001539010 x21: ffffbcc65714b22c x20: 6b6b6b6b6b6b6b6b x19: 01adafad6dadad80 x18: 0000000000000000 x17: ffffbcc6579fbac8 x16: ffffbcc657a04300 x15: ffffbcc657a027f4 x14: ffffbcc656f969cc x13: ffffbcc6579fdc80 x12: ffffbcc6579fb194 x11: ffffbcc6579fbc34 x10: 0000000000000000 x9 : ffffbcc65714b22c x8 : ffff80008009b880 x7 : 0000000000000000 x6 : ffff80008009b940 x5 : ffff80008009b8c0 x4 : ffff22e000940518 x3 : ffff22e006f54f40 x2 : ffffbcc657a02268 x1 : ffff80007fffffff x0 : ffffc1ffc0000000 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 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@vger.kernel.org Signed-off-by: André Draszik andre.draszik@linaro.org --- 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@linaro.org --- In my case, as per above trace I initially encountered an error in ufshcd_verify_dev_init(), which made me notice this problem. For reproducing, it'd be possible to change that function to just return an error.
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 | 27 +++++++++++++++++---------- drivers/ufs/host/ufshcd-pci.c | 2 -- drivers/ufs/host/ufshcd-pltfrm.c | 11 ++++------- include/ufs/ufshcd.h | 1 - 4 files changed, 21 insertions(+), 20 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 43ddae7318cb..84089f3f62b0 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 @@ -10307,6 +10297,16 @@ static int ufshcd_set_dma_mask(struct ufs_hba *hba) return dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(32)); }
+/** + * ufshcd_scsi_host_put_callback - deallocate underlying Scsi_Host and + * thereby the Host Bus Adapter (HBA) + * @host: pointer to SCSI host + */ +static void ufshcd_scsi_host_put_callback(void *host) +{ + scsi_host_put(host); +} + /** * ufshcd_alloc_host - allocate Host Bus Adapter (HBA) * @dev: pointer to device handle @@ -10334,6 +10334,13 @@ 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_scsi_host_put_callback, + 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..adb0a65d9df5 100644 --- a/drivers/ufs/host/ufshcd-pltfrm.c +++ b/drivers/ufs/host/ufshcd-pltfrm.c @@ -488,13 +488,13 @@ int ufshcd_pltfrm_init(struct platform_device *pdev, if (err) { dev_err(dev, "%s: clock parse failed %d\n", __func__, err); - goto dealloc_host; + goto out; } err = ufshcd_parse_regulator_info(hba); if (err) { dev_err(dev, "%s: regulator init failed %d\n", __func__, err); - goto dealloc_host; + goto out; }
ufshcd_init_lanes_per_dir(hba); @@ -502,14 +502,14 @@ 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; + goto out; }
err = ufshcd_init(hba, mmio_base, irq); if (err) { dev_err_probe(dev, err, "Initialization failed with error %d\n", err); - goto dealloc_host; + goto out; }
pm_runtime_set_active(dev); @@ -517,8 +517,6 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
return 0;
-dealloc_host: - ufshcd_dealloc_host(hba); out: return err; } @@ -534,7 +532,6 @@ 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,