# CVE-2026-74728: linux: In the Linux kernel, the following vulnerability has been resolved: xfs: handle NULL b_addr in xfs_buf_free When xf... CVE-2026-74728 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-74728, released September 4, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-74728 - Priority: High - CVSS: n/a (important) - EPSS: 0.0017 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Aug 22, 2026 ## Description In the Linux kernel, the following vulnerability has been resolved: xfs: handle NULL b_addr in xfs_buf_free When xfs_buf_alloc_backing_mem() fails, xfs_buf_free() is called with bp->b_addr still NULL. The code falls through to the folio_put path which calls virt_to_folio(NULL), dereferencing an invalid address and causing a kernel crash. Call Trace: xfs_buf_free+0x25f/0x510 xfs_buf_alloc+0xc98/0x19b0 xfs_buf_find_insert+0x55/0x14d0 xfs_buf_get_map+0x122b/0x17c0 xfbtree_init_leaf_block+0x11c/0x4a0 xfbtree_init+0x1bb/0x460 xrep_rmap_setup_scan+0x100/0x1f0 xrep_rmapbt+0x41/0xc0 Fix this by skipping folio_put() when bp->b_addr is NULL. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel-livepatch-6.18.48-107.148 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-74728](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74728.md) | Sep 4, 2026 | | Linux | linux Debian 14 | 7.1.9-1 | [DEBIAN-CVE-2026-74728](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74728.md) | Sep 4, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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