# CVE-2026-64158: linux: In the Linux kernel, the following vulnerability has been resolved:  netfs: Fix write streaming disablement if fd ope...

CVE-2026-64158 is fixed in 51 products on 1 platform, first by ALAS2023-2026-1894, released June 22, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-64158
- Priority: High
- CVSS: 7.3 (high)
- EPSS: n/a
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 22, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  netfs: Fix write streaming disablement if fd open O_RDWR  In netfs_perform_write(), "write streaming" (the caching of dirty data in dirty but !uptodate folios) is performed to avoid the need to read data that is just going to get immediately overwritten.  However, this is/will be disabled in three circumstances: if the fd is open O_RDWR, if fscache is in use (as we need to round out the blocks for DIO) or if content encryption is enabled (again for rounding out purposes).  The idea behind disabling it if the fd is open O_RDWR is that we'd need to flush the write-streaming page before we could read the data, particularly through mmap.  But netfs now fills in the gaps if ->read_folio() is called on the page, so that is unnecessary.  Further, this doesn't actually work if a separate fd is open for reading.  Fix this by removing the check for O_RDWR, thereby allowing streaming writes even when we might read.  This caused a number of problems with the generic/522 xfstest, but those are now fixed.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bpftool6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | bpftool6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-azure sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23237-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23237-1.md) | Aug 11, 2026 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.37.1.160000.2.19 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.37.1.160000.2.19 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-livepatch-6.12.92-122.166 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel-livepatch-6.18.35-68.127 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 |
| Linux | kernel6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-devel amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-headers amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-tools amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | kernel6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-devel amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-headers amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-tools amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.94-1 | [DEBIAN-CVE-2026-64158](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64158.md) | Jul 20, 2026 |
| Linux | linux Debian 14 | 7.0.12-1 | [DEBIAN-CVE-2026-64158](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64158.md) | Jul 20, 2026 |
| Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | perf6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | perf6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | python3-perf6.12 amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.92-122.166.amzn2023 | [ALAS2023-2026-1894](https://patchblox.com/security/data/fix/linux/alas2023-2026-1894.md) | Jun 22, 2026 |
| Linux | python3-perf6.18 amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |
| Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.35-68.127.amzn2023 | [ALAS2023-2026-1881](https://patchblox.com/security/data/fix/linux/alas2023-2026-1881.md) | Jun 22, 2026 |

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