CVE-2024-56678
HighIn 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
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-416CVE-2024-56678 is a Use After Free vulnerability
What is Use After Free?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.13
and later are affected. Fixed in
5.15.174,
6.1.120,
6.6.64,
6.11.11,
6.12.2,
6.13
and their respective stable series.
References
The following references provide additional information about CVE-2024-56678 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
-
-
PatchKernel patch commithttps://git.kernel.org/stable/c/06dbbb4d5f7126b6307ab807cbf04ecfc459b933
-
PatchKernel patch commithttps://git.kernel.org/stable/c/15f78d2c3d1452645bd8b9da909b0ca266f83c43
-
PatchKernel patch commithttps://git.kernel.org/stable/c/4d2655754e94741b159aa807b72ea85518a65fd5
Frequently asked questions
-
What is CVE-2024-56678?
CVE-2024-56678 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 5.13 onward and has been patched in 5.15.174, 6.1.120, 6.6.64 and others. CVE-2024-56678 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
What is the CVSS score for CVE-2024-56678?
CVE-2024-56678 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2024-56678?
Yes — CVE-2024-56678 has been patched. Fixed versions include 5.15.174, 6.1.120, 6.6.64 and others. If you are running Linux kernel 5.13 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2024-56678 actively exploited?
No — CVE-2024-56678 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
-
What is Use After Free (CWE-416)?
The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →