--- id: CVE-2026-45984 title: |- In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in iomap inline data write path The inline data buffer head (dibh) is being released prematurely in gfs2_iomap_begin() via release_metapath() … summary: |- In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in iomap inline data write path The inline data buffer head (dibh) is being released prematurely in gfs2_iomap_begin() via release_metapath() … severity: high cvss: 7.8 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H' cwe: - CWE-416 - CWE-826 vendor: linux product: linux_kernel affected: - 'linux_kernel >= 5.2, < 5.10.252' - 'linux_kernel >= 5.11, < 5.15.202' - 'linux_kernel >= 5.16, < 6.1.165' - 'linux_kernel >= 6.2, < 6.6.128' - 'linux_kernel >= 6.7, < 6.12.75' - 'linux_kernel >= 6.13, < 6.18.14' - 'linux_kernel >= 6.19, < 6.19.4' patched: - linux_kernel 6.19.4 published: '2026-05-27' updated: '2026-07-07' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45984' references: - url: 'https://git.kernel.org/stable/c/1403989d1b502f4a2c0d0b42ccf1c25748442eff' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/1cae1bafdf9caa9b462b19af06b1a06902e4e142' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/6d76febba07c40bcf358f63216d36ea68cf1c215' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/764c3c84b5683e608f43735c803a5f415046686c' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/815ddd27c0c7171a99fe802fdb19098ddef8b19d' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/87d4954b5c59735a99ea98cb208d47130f6dce7d' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/d87268326b277af3665237ac76a73dd9fa8e21b4' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/faddeb848305e79db89ee0479bb0e33380656321' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://access.redhat.com/errata/RHSA-2026:27789' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:33743' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:35894' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:36049' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/security/cve/CVE-2026-45984' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2481922' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45984.json label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://www.cve.org/CVERecord?id=CVE-2026-45984' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45984' - url: >- https://lore.kernel.org/linux-cve-announce/2026052739-CVE-2026-45984-107d@gregkh/T - url: 'https://access.redhat.com/errata/RHSA-2026:61692' - url: 'https://access.redhat.com/errata/RHSA-2026:63189' - url: 'https://access.redhat.com/errata/RHSA-2026:51603' - url: 'https://access.redhat.com/errata/RHSA-2026:36767' - url: 'https://access.redhat.com/errata/RHSA-2026:38902' - url: 'https://access.redhat.com/errata/RHSA-2026:59143' - url: 'https://access.redhat.com/errata/RHSA-2026:59146' - url: 'https://access.redhat.com/errata/RHSA-2026:55444' - url: 'https://access.redhat.com/errata/RHSA-2026:59142' - url: 'https://access.redhat.com/errata/RHSA-2026:59147' - url: 'https://access.redhat.com/errata/RHSA-2026:59145' - url: 'https://access.redhat.com/errata/RHSA-2026:59148' - url: 'https://access.redhat.com/errata/RHSA-2026:59149' - url: 'https://access.redhat.com/errata/RHSA-2026:51604' tags: - nvd - cve.org - csaf - vex - red-hat epss: 0.00474 epssPercentile: 0.38288 ingestedAt: '2026-07-07T12:52:59.608Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in iomap inline data write path The inline data buffer head (dibh) is being released prematurely in gfs2_iomap_begin() via release_metapath() while iomap->inline_data still points to dibh->b_data. This causes a use-after-free when iomap_write_end_inline() later attempts to write to the inline data area. The bug sequence: 1. gfs2_iomap_begin() calls gfs2_meta_inode_buffer() to read inode metadata into dibh 2. Sets iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode) 3. Calls release_metapath() which calls brelse(dibh), dropping refcount to 0 4. kswapd reclaims the page (~39ms later in the syzbot report) 5. iomap_write_end_inline() tries to memcpy() to iomap->inline_data 6. KASAN detects use-after-free write to freed memory Fix by storing dibh in iomap->private and incrementing its refcount with get_bh() in gfs2_iomap_begin(). The buffer is then properly released in gfs2_iomap_end() after the inline write completes, ensuring the page stays alive for the entire iomap operation. Note: A C reproducer is not available for this issue. The fix is based on analysis of the KASAN report and code review showing the buffer head is freed before use. [agruenba: Take buffer head reference in gfs2_iomap_begin() to avoid leaks in gfs2_iomap_get() and gfs2_iomap_alloc().] ## Affected - `linux_kernel >= 5.2, < 5.10.252` - `linux_kernel >= 5.11, < 5.15.202` - `linux_kernel >= 5.16, < 6.1.165` - `linux_kernel >= 6.2, < 6.6.128` - `linux_kernel >= 6.7, < 6.12.75` - `linux_kernel >= 6.13, < 6.18.14` - `linux_kernel >= 6.19, < 6.19.4` ## Remediation Upgrade past the affected range: - `linux_kernel 6.19.4` ## Vendor advisories - **RHSA-2026:61692** · Red Hat · fixed in: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61692) - **RHSA-2026:63189** · Red Hat · fixed in: Red Hat Enterprise Linux for Real Time (v. 7 ELS) · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63189) - **RHSA-2026:51603** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2) · released 2026-08-07 · [advisory](https://access.redhat.com/errata/RHSA-2026:51603) - **RHSA-2026:36767** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4) · released 2026-07-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:36767) - **RHSA-2026:38902** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6) · released 2026-07-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:38902) - **RHSA-2026:27789** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-06-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:27789) - **RHSA-2026:59143** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:59143) - **RHSA-2026:33743** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-06-30 · [advisory](https://access.redhat.com/errata/RHSA-2026:33743) - **RHSA-2026:59146** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:59146) - **RHSA-2026:35894** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) · released 2026-07-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:35894) - **RHSA-2026:55444** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS E4S (v.8.8), Red Hat Enterprise Linux BaseOS TUS (v.8.8) · released 2026-08-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:55444) - **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45984.json)