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().]
References
Configurations
Configuration 1 (hide)
|
History
16 Jun 2026, 02:39
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | CWE-416 | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| References | () https://git.kernel.org/stable/c/1403989d1b502f4a2c0d0b42ccf1c25748442eff - Patch | |
| References | () https://git.kernel.org/stable/c/1cae1bafdf9caa9b462b19af06b1a06902e4e142 - Patch | |
| References | () https://git.kernel.org/stable/c/6d76febba07c40bcf358f63216d36ea68cf1c215 - Patch | |
| References | () https://git.kernel.org/stable/c/764c3c84b5683e608f43735c803a5f415046686c - Patch | |
| References | () https://git.kernel.org/stable/c/815ddd27c0c7171a99fe802fdb19098ddef8b19d - Patch | |
| References | () https://git.kernel.org/stable/c/87d4954b5c59735a99ea98cb208d47130f6dce7d - Patch | |
| References | () https://git.kernel.org/stable/c/d87268326b277af3665237ac76a73dd9fa8e21b4 - Patch | |
| References | () https://git.kernel.org/stable/c/faddeb848305e79db89ee0479bb0e33380656321 - Patch |
30 May 2026, 11:17
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
27 May 2026, 14:17
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-27 14:17
Updated : 2026-06-17 10:52
NVD link : CVE-2026-45984
Mitre link : CVE-2026-45984
CVE.ORG link : CVE-2026-45984
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-416
Use After Free
