Bug 2300491 (CVE-2024-41096) - CVE-2024-41096 kernel: PCI/MSI: Fix UAF in msi_capability_init
Summary: CVE-2024-41096 kernel: PCI/MSI: Fix UAF in msi_capability_init
Keywords:
Status: NEW
Alias: CVE-2024-41096
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2301686
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-07-29 16:22 UTC by OSIDB Bzimport
Modified: 2024-09-27 23:31 UTC (History)
4 users (show)

Fixed In Version: kernel 6.6.37, kernel 6.9.8, kernel 6.10
Doc Type: If docs needed, set a value
Doc Text:
A use after free vulnerability was found in the Linux Kernel. Failure propagates back to pci_msi_setup_msi_irqs() in msi_capability_init(), which accesses the descriptor for unmasking in the error exit path, leading to a loss of confidentiality, integrity, and availability.
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2024:6650 0 None None None 2024-09-12 14:28:40 UTC
Red Hat Product Errata RHSA-2024:6567 0 None None None 2024-09-11 01:01:18 UTC

Description OSIDB Bzimport 2024-07-29 16:22:59 UTC 
In the Linux kernel, the following vulnerability has been resolved:

PCI/MSI: Fix UAF in msi_capability_init

KFENCE reports the following UAF:

 BUG: KFENCE: use-after-free read in __pci_enable_msi_range+0x2c0/0x488

 Use-after-free read at 0x0000000024629571 (in kfence-#12):
  __pci_enable_msi_range+0x2c0/0x488
  pci_alloc_irq_vectors_affinity+0xec/0x14c
  pci_alloc_irq_vectors+0x18/0x28

 kfence-#12: 0x0000000008614900-0x00000000e06c228d, size=104, cache=kmalloc-128

 allocated by task 81 on cpu 7 at 10.808142s:
  __kmem_cache_alloc_node+0x1f0/0x2bc
  kmalloc_trace+0x44/0x138
  msi_alloc_desc+0x3c/0x9c
  msi_domain_insert_msi_desc+0x30/0x78
  msi_setup_msi_desc+0x13c/0x184
  __pci_enable_msi_range+0x258/0x488
  pci_alloc_irq_vectors_affinity+0xec/0x14c
  pci_alloc_irq_vectors+0x18/0x28

 freed by task 81 on cpu 7 at 10.811436s:
  msi_domain_free_descs+0xd4/0x10c
  msi_domain_free_locked.part.0+0xc0/0x1d8
  msi_domain_alloc_irqs_all_locked+0xb4/0xbc
  pci_msi_setup_msi_irqs+0x30/0x4c
  __pci_enable_msi_range+0x2a8/0x488
  pci_alloc_irq_vectors_affinity+0xec/0x14c
  pci_alloc_irq_vectors+0x18/0x28

Descriptor allocation done in:
__pci_enable_msi_range
    msi_capability_init
        msi_setup_msi_desc
            msi_insert_msi_desc
                msi_domain_insert_msi_desc
                    msi_alloc_desc
                        ...

Freed in case of failure in __msi_domain_alloc_locked()
__pci_enable_msi_range
    msi_capability_init
        pci_msi_setup_msi_irqs
            msi_domain_alloc_irqs_all_locked
                msi_domain_alloc_locked
                    __msi_domain_alloc_locked => fails
                    msi_domain_free_locked
                        ...

That failure propagates back to pci_msi_setup_msi_irqs() in
msi_capability_init() which accesses the descriptor for unmasking in the
error exit path.

Cure it by copying the descriptor and using the copy for the error exit path
unmask operation.

[ tglx: Massaged change log ]
Comment 1 Mauro Matteo Cascella 2024-07-30 15:48:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024072954-CVE-2024-41096-4ed0@gregkh/T
Comment 2 Mauro Matteo Cascella 2024-07-30 15:49:18 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2301686]
Comment 7 errata-xmlrpc 2024-09-11 01:01:17 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2024:6567 https://access.redhat.com/errata/RHSA-2024:6567
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