CVE-2024-56678

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Source
https://cve.org/CVERecord?id=CVE-2024-56678
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56678.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2024-56678
Downstream
Related
Published
2024-12-28T09:46:07Z
Modified
2026-08-12T03:30:49Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
powerpc/mm/fault: Fix kfence page fault reporting
Details

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

powerpc/mm/fault: Fix kfence page fault reporting

copy_from_kernel_nofault() can be called when doing read of /proc/kcore. /proc/kcore can have some unmapped kfence objects which when read via copy_from_kernel_nofault() can cause page faults. Since *_nofault() functions define their own fixup table for handling fault, use that instead of asking kfence to handle such faults.

Hence we search the exception tables for the nip which generated the fault. If there is an entry then we let the fixup table handler handle the page fault by returning an error from within ___do_page_fault().

This can be easily triggered if someone tries to do dd from /proc/kcore. eg. dd if=/proc/kcore of=/dev/null bs=1M

Some example false negatives:

=============================== BUG: KFENCE: invalid read in copy_from_kernel_nofault+0x9c/0x1a0 Invalid read at 0xc0000000fdff0000: copy_from_kernel_nofault+0x9c/0x1a0 0xc00000000665f950 read_kcore_iter+0x57c/0xa04 proc_reg_read_iter+0xe4/0x16c vfs_read+0x320/0x3ec ksys_read+0x90/0x154 system_call_exception+0x120/0x310 system_call_vectored_common+0x15c/0x2ec

BUG: KFENCE: use-after-free read in copy_from_kernel_nofault+0x9c/0x1a0 Use-after-free read at 0xc0000000fe050000 (in kfence-#2): copy_from_kernel_nofault+0x9c/0x1a0 0xc00000000665f950 read_kcore_iter+0x57c/0xa04 proc_reg_read_iter+0xe4/0x16c vfs_read+0x320/0x3ec ksys_read+0x90/0x154 system_call_exception+0x120/0x310 system_call_vectored_common+0x15c/0x2ec

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56678.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
90cbac0e995dd92f7bcf82f74aa50250bf194a4a
Fixed
e0a470b5733c1fe068d5c58b0bb91ad539604bc6
Fixed
4d2655754e94741b159aa807b72ea85518a65fd5
Fixed
9ea8d8bf9b625e8ad3be6b0432aecdc549914121
Fixed
7eaeb7a49b6d16640f9f3c9074c05175d74c710b
Fixed
15f78d2c3d1452645bd8b9da909b0ca266f83c43
Fixed
06dbbb4d5f7126b6307ab807cbf04ecfc459b933

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56678.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.13.0
Fixed
5.15.174
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.120
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.64
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.11.11
Type
ECOSYSTEM
Events
Introduced
6.12.0
Fixed
6.12.2

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56678.json"