Description
In the Linux kernel, the following vulnerability has been resolved:
fsdax: dax_unshare_iter needs to copy entire blocks
The code that copies data from srcmap to iomap in dax_unshare_iter is
very very broken, which bfoster's recent fsx changes have exposed.
If the pos and len passed to dax_file_unshare are not aligned to an
fsblock boundary, the iter pos and length in the _iter function will
reflect this unalignment.
dax_iomap_direct_access always returns a pointer to the start of the
kmapped fsdax page, even if its pos argument is in the middle of that
page. This is catastrophic for data integrity when iter->pos is not
aligned to a page, because daddr/saddr do not point to the same byte in
the file as iter->pos. Hence we corrupt user data by copying it to the
wrong place.
If iter->pos + iomap_length() in the _iter function not aligned to a
page, then we fail to copy a full block, and only partially populate the
destination block. This is catastrophic for data confidentiality
because we expose stale pmem contents.
Fix both of these issues by aligning copy_pos/copy_len to a page
boundary (remember, this is fsdax so 1 fsblock == 1 base page) so that
we always copy full blocks.
We're not done yet -- there's no call to invalidate_inode_pages2_range,
so programs that have the file range mmap'd will continue accessing the
old memory mapping after the file metadata updates have completed.
Be careful with the return value -- if the unshare succeeds, we still
need to return the number of bytes that the iomap iter thinks we're
operating on.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.1.113 – < 6.1.116, 6.2 | 6.1.116 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.11.7-1 | — |
| Debian 13 | linux | 6.11.7-1 | — |
| Debian 12 | linux | 6.1.119-1 | DSA-5818-1 |
| Debian 11 | linux-6.1 | 6.1.119-1~deb11u1 | DLA-4008-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux | 6.8.0-58.60 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1027.29 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1027.32 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-azure-6.11 | 6.11.0-1012.12~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1014.15 | USN-7468-1 |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1028.30 | USN-7450-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.11 | 6.11.0-1011.11~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1023.27 | USN-7450-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1010.12 | USN-7450-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1024.24 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1026.29 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.11 | 6.11.0-1007.7 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1026.29.1 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1008.8 | — |
| Ubuntu 24.04 LTS | linux-oem-6.11 | 6.11.0-1015.15 | USN-7310-1 |
| Ubuntu 24.04 LTS | linux-oem-6.8 | 6.8.0-1026.26 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1024.25 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1028.32 | USN-7524-1 |
| Ubuntu 24.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv +1 | 6.8.0-58.60.1 | USN-7449-1 |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1017.18 | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1027.29~22.04.1 | USN-7451-1 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1027.32~22.04.1 | USN-7449-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1028.30~22.04.1 | USN-7452-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-58.60~22.04.1 | USN-7449-2 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1024.24~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1026.29~22.04.1 | USN-7449-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1024.25~22.04.1 | USN-7449-1 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 +1 | 6.8.0-58.60.1~22.04.1 | USN-7449-1 |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2023.24 | USN-7523-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1020.21 | USN-7453-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1020.21~22.04.1 | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-78.78+fips1 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.30.1 | SUSE-SU-2024:4318-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.20.1 | SUSE-SU-2024:4316-1 |
| SLES 15 SP6 | kernel-coco +3 | 6.4.0-15061.9.coco15sp6.1 | SUSE-SU-2024:4387-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.30.1.150600.12.12.6 | SUSE-SU-2024:4318-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.1 | kernel-default-base | 6.4.0-24.1.21.4 | SUSE-SU-2025:20247-1 |
| SLE Micro 6.1 | kernel-livepatch-MICRO-6-0-RT_Update_4 | 1-1.1 | SUSE-SU-2025:20246-1 |
| SLE Micro 6.1 | kernel-livepatch-MICRO-6-0_Update_2 +1 | 8-1.1 | SUSE-SU-2025:20544-1, SUSE-SU-2025:20540-1 |
| SLE Micro 6.1 | kernel-livepatch-MICRO-6-0_Update_4 | 1-1.2 | SUSE-SU-2025:20247-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-22.1 | SUSE-SU-2025:20246-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-24.1 | SUSE-SU-2025:20247-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-24.1.21.4 | SUSE-SU-2025:20164-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0-RT_Update_4 | 1-1.1 | SUSE-SU-2025:20163-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0_Update_2 +1 | 8-1.1 | SUSE-SU-2025:20525-1, SUSE-SU-2025:20517-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0_Update_3 +1 | 8-1.2 | SUSE-SU-2025:20526-1, SUSE-SU-2025:20518-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0_Update_4 | 1-1.2 | SUSE-SU-2025:20164-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-22.1 | SUSE-SU-2025:20163-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-24.1 | SUSE-SU-2025:20164-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.30.1 | SUSE-SU-2024:4318-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_0 | 18-150600.3.1 | SUSE-SU-2025:02390-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_1 | 17-150600.2.1 | SUSE-SU-2025:02388-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_4 | 12-150600.2.1 | SUSE-SU-2025:02411-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_5 | 11-150600.2.1 | SUSE-SU-2025:02412-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_6 | 1-150600.1.3.1 | SUSE-SU-2024:4314-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_0 | 19-150600.4.49.1 | SUSE-SU-2025:02440-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_4 +2 | 13-150600.2.1 | SUSE-SU-2025:02449-1, SUSE-SU-2025:02420-1, SUSE-SU-2025:02389-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_6 | 1-150600.13.3.5 | SUSE-SU-2024:4318-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.20.1 | SUSE-SU-2024:4314-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 6.11.8-1.1 | openSUSE-SU-2024:14500-1 |
| openSUSE Tumbleweed | kernel-source-longterm | 6.12.11-1.1 | openSUSE-SU-2025:14705-1 |
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.30.1 | SUSE-SU-2024:4318-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.20.1 | SUSE-SU-2024:4316-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.30.1.150600.12.12.6 | SUSE-SU-2024:4318-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.20.1 | SUSE-SU-2024:4314-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.64.2-1 | — |
Advisories 37
- WID-SEC-2024-3397 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 11, 2026
- USN-7449-1 linux, linux-aws, linux-azure, linux-azure-6.8, linux-ibm, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency, linux-oem-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7450-1 linux-gcp, linux-gke, linux-gkeop vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7468-1 linux-azure-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7453-1 linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7451-1 linux-aws-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7524-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7523-1 linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7310-1 linux-oem-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7452-1 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7449-2 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- SUSE-SU-2025:20163-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20525-1 Security update for kernel-livepatch-MICRO-6-0_Update_2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20526-1 Security update for kernel-livepatch-MICRO-6-0_Update_3 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20246-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20164-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:02440-1 Security update for the Linux Kernel (Live Patch 0 for SLE 15 SP6) SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:02389-1 Security update for the Linux Kernel RT (Live Patch 3 for SLE 15 SP6) SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20544-1 Security update for kernel-livepatch-MICRO-6-0-RT_Update_2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20518-1 Security update for kernel-livepatch-MICRO-6-0-RT_Update_3 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20247-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20517-1 Security update for kernel-livepatch-MICRO-6-0-RT_Update_2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20540-1 Security update for kernel-livepatch-MICRO-6-0_Update_2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:02390-1 Security update for the Linux Kernel RT (Live Patch 0 for SLE 15 SP6) SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:02420-1 Security update for the Linux Kernel RT (Live Patch 2 for SLE 15 SP6) SUSE / openSUSE Security Updates · Mar 23, 2026
- DLA-4008-1 linux-6.1 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-5818-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2025:02411-1 Security update for the Linux Kernel RT (Live Patch 4 for SLE 15 SP6) SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4318-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:02388-1 Security update for the Linux Kernel RT (Live Patch 1 for SLE 15 SP6) SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:02449-1 Security update for the Linux Kernel (Live Patch 4 for SLE 15 SP6) SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4316-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2025:14705-1 kernel-devel-longterm-6.12.11-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:02412-1 Security update for the Linux Kernel RT (Live Patch 5 for SLE 15 SP6) SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14500-1 kernel-devel-6.11.8-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4387-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:4314-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026