Yüksek CVSS 7.8

CVE-2026-45984: Linux Kernel: serbest bırakılmış belleğin kullanımı

Yayın: 27 Mayıs 2026 17:17 · Güncelleme: 6 Kasım 2026 10:19

Açıklama (NVD)

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().]

Özet bilgiler

Ürün: Linux Linux Kernel
CVSS v3.1: 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: %0,18 (yüzdelik 8)
CWE: CWE-416
Yama: Mevcut

Etkilenen sürümler

Ürün	Başlangıç	Bitiş	Düzeltildi
linux-linux-kernel	5.2	—	5.10.252
linux-linux-kernel	5.11	—	5.15.202
linux-linux-kernel	5.16	—	6.1.165
linux-linux-kernel	6.2	—	6.6.128
linux-linux-kernel	6.7	—	6.12.75
linux-linux-kernel	6.13	—	6.18.14
linux-linux-kernel	6.19	—	6.19.4

Kaynaklar

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