device-dax: correct pgoff align in dax_set_mapping()
pgoff should be aligned using ALIGN_DOWN() instead of ALIGN(). Otherwise,
vmf->address not aligned to fault_size will be aligned to the next
alignment, that can result in memory failure getting the wrong address.
It's a subtle situation that only can be observed in
page_mapped_in_vma() after the page is page fault handled by
dev_dax_huge_fault. Generally, there is little chance to perform
page_mapped_in_vma in dev-dax's page unless in specific error injection
to the dax device to trigger an MCE - memory-failure. In that case,
page_mapped_in_vma() will be triggered to determine which task is
accessing the failure address and kill that task in the end.
We used self-developed dax device (which is 2M aligned mapping) , to
perform error injection to random address. It turned out that error
injected to non-2M-aligned address was causing endless MCE until panic.
Because page_mapped_in_vma() kept resulting wrong address and the task
accessing the failure address was never killed properly:
[ 3783.719419] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3784.049006] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3784.049190] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3784.448042] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3784.448186] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3784.792026] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3784.792179] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3785.162502] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3785.162633] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3785.461116] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3785.461247] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3785.764730] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3785.764859] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3786.042128] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3786.042259] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3786.464293] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3786.464423] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3786.818090] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3786.818217] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
[ 3787.085297] mce: Uncorrected hardware memory error in user-access at
200c9742380
[ 3787.085424] Memory failure: 0x200c9742: recovery action for dax page:
Recovered
It took us several weeks to pinpoint this problem, but we eventually
used bpftrace to trace the page fault and mce address and successfully
identified the issue.
Joao added:
; Likely we never reproduce in production because we always pin
: device-dax regions in the region align they provide (Qemu does
: similarly with prealloc in hugetlb/file backed memory). I think this
: bug requires that we touch *unpinned* device-dax regions unaligned to
: the device-dax selected alignment (page size i.e. 4K/2M/1G)
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Ubuntu USN |
USN-7276-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7277-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7310-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7383-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7383-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7384-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7384-2 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-7385-1 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-7386-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-7403-1 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-7451-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7468-1 | Linux kernel (Azure, N-Series) vulnerabilities |
Ubuntu USN |
USN-7523-1 | Linux kernel (Raspberry Pi Real-time) vulnerabilities |
Ubuntu USN |
USN-7524-1 | Linux kernel (Raspberry Pi) vulnerabilities |
Mon, 03 Nov 2025 23:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 14 May 2025 02:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux |
Thu, 13 Feb 2025 00:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-126 |
Fri, 25 Oct 2024 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Tue, 22 Oct 2024 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 22 Oct 2024 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Mon, 21 Oct 2024 19:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: device-dax: correct pgoff align in dax_set_mapping() pgoff should be aligned using ALIGN_DOWN() instead of ALIGN(). Otherwise, vmf->address not aligned to fault_size will be aligned to the next alignment, that can result in memory failure getting the wrong address. It's a subtle situation that only can be observed in page_mapped_in_vma() after the page is page fault handled by dev_dax_huge_fault. Generally, there is little chance to perform page_mapped_in_vma in dev-dax's page unless in specific error injection to the dax device to trigger an MCE - memory-failure. In that case, page_mapped_in_vma() will be triggered to determine which task is accessing the failure address and kill that task in the end. We used self-developed dax device (which is 2M aligned mapping) , to perform error injection to random address. It turned out that error injected to non-2M-aligned address was causing endless MCE until panic. Because page_mapped_in_vma() kept resulting wrong address and the task accessing the failure address was never killed properly: [ 3783.719419] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3784.049006] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3784.049190] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3784.448042] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3784.448186] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3784.792026] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3784.792179] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3785.162502] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3785.162633] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3785.461116] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3785.461247] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3785.764730] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3785.764859] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3786.042128] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3786.042259] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3786.464293] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3786.464423] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3786.818090] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3786.818217] Memory failure: 0x200c9742: recovery action for dax page: Recovered [ 3787.085297] mce: Uncorrected hardware memory error in user-access at 200c9742380 [ 3787.085424] Memory failure: 0x200c9742: recovery action for dax page: Recovered It took us several weeks to pinpoint this problem, but we eventually used bpftrace to trace the page fault and mce address and successfully identified the issue. Joao added: ; Likely we never reproduce in production because we always pin : device-dax regions in the region align they provide (Qemu does : similarly with prealloc in hugetlb/file backed memory). I think this : bug requires that we touch *unpinned* device-dax regions unaligned to : the device-dax selected alignment (page size i.e. 4K/2M/1G) | |
| Title | device-dax: correct pgoff align in dax_set_mapping() | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T20:43:59.526Z
Reserved: 2024-10-21T12:17:06.064Z
Link: CVE-2024-50022
Updated: 2025-11-03T22:24:33.602Z
Status : Modified
Published: 2024-10-21T20:15:15.690
Modified: 2025-11-03T23:16:41.263
Link: CVE-2024-50022
OpenCVE Enrichment
No data.
Debian DLA
Ubuntu USN