linux-cve-announce - CVE-2025-21739: scsi: ufs: core: Fix use-after free in init error and remove paths

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025022659-CVE-2025-21739-5578@gregkh>
Date: Wed, 26 Feb 2025 18:11:21 -0800
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2025-21739: scsi: ufs: core: Fix use-after free in init error and remove paths

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

scsi: ufs: core: Fix use-after free in init error and remove paths

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

The Linux kernel CVE team has assigned CVE-2025-21739 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.12 with commit d76d9d7d1009968dd3a0fc30e5f5ee9fbffc1350 and fixed in 6.12.14 with commit 0c77c0d754fe83cb154715fcfec6c3faef94f207
	Issue introduced in 5.12 with commit d76d9d7d1009968dd3a0fc30e5f5ee9fbffc1350 and fixed in 6.13.3 with commit 9c185beae09a3eb85f54777edafa227f7e03075d
	Issue introduced in 5.12 with commit d76d9d7d1009968dd3a0fc30e5f5ee9fbffc1350 and fixed in 6.14-rc2 with commit f8fb2403ddebb5eea0033d90d9daae4c88749ada

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2025-21739
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/ufs/core/ufshcd.c
	drivers/ufs/host/ufshcd-pci.c
	drivers/ufs/host/ufshcd-pltfrm.c
	include/ufs/ufshcd.h


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/0c77c0d754fe83cb154715fcfec6c3faef94f207
	https://git.kernel.org/stable/c/9c185beae09a3eb85f54777edafa227f7e03075d
	https://git.kernel.org/stable/c/f8fb2403ddebb5eea0033d90d9daae4c88749ada