# CVE-2025-68261

## Summary

- **CVE ID:** CVE-2025-68261
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** N/A
- **Published:** Dec 16, 2025
- **Last Modified:** Sep 8, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

ext4: add i_data_sem protection in ext4_destroy_inline_data_nolock()

Fix a race between inline data destruction and block mapping.

The function ext4_destroy_inline_data_nolock() changes the inode data
layout by clearing EXT4_INODE_INLINE_DATA and setting EXT4_INODE_EXTENTS.
At the same time, another thread may execute ext4_map_blocks(), which
tests EXT4_INODE_EXTENTS to decide whether to call ext4_ext_map_blocks()
or ext4_ind_map_blocks().

Without i_data_sem protection, ext4_ind_map_blocks() may receive inode
with EXT4_INODE_EXTENTS flag and triggering assert.

kernel BUG at fs/ext4/indirect.c:546!
EXT4-fs (loop2): unmounting filesystem.
invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:ext4_ind_map_blocks.cold+0x2b/0x5a fs/ext4/indirect.c:546

Call Trace:
 <TASK>
 ext4_map_blocks+0xb9b/0x16f0 fs/ext4/inode.c:681
 _ext4_get_block+0x242/0x590 fs/ext4/inode.c:822
 ext4_block_write_begin+0x48b/0x12c0 fs/ext4/inode.c:1124
 ext4_write_begin+0x598/0xef0 fs/ext4/inode.c:1255
 ext4_da_write_begin+0x21e/0x9c0 fs/ext4/inode.c:3000
 generic_perform_write+0x259/0x5d0 mm/filemap.c:3846
 ext4_buffered_write_iter+0x15b/0x470 fs/ext4/file.c:285
 ext4_file_write_iter+0x8e0/0x17f0 fs/ext4/file.c:679
 call_write_iter include/linux/fs.h:2271 [inline]
 do_iter_readv_writev+0x212/0x3c0 fs/read_write.c:735
 do_iter_write+0x186/0x710 fs/read_write.c:861
 vfs_iter_write+0x70/0xa0 fs/read_write.c:902
 iter_file_splice_write+0x73b/0xc90 fs/splice.c:685
 do_splice_from fs/splice.c:763 [inline]
 direct_splice_actor+0x10f/0x170 fs/splice.c:950
 splice_direct_to_actor+0x33a/0xa10 fs/splice.c:896
 do_splice_direct+0x1a9/0x280 fs/splice.c:1002
 do_sendfile+0xb13/0x12c0 fs/read_write.c:1255
 __do_sys_sendfile64 fs/read_write.c:1323 [inline]
 __se_sys_sendfile64 fs/read_write.c:1309 [inline]
 __x64_sys_sendfile64+0x1cf/0x210 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x35/0x80 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

## Affected Products

- Linux — Linux (c755e251357a0cee0679081f08c3f4ba797a8009)
- Linux — Linux (3e96c3fdcfccb321a9e1623f78cc71b44593e965)
- Linux — Linux (5781ac24bbd998ebb1ff30143bb06244d847af48)
- Linux — Linux (9b06cce3ca4d60d442c39bfa7c058b71b1cee6c2)
- Linux — Linux (da1e40237f8f3516581b534c484c236a79ccfd14)
- Linux — Linux (7cf6b709b6412afd1d93b2c4b37163c3602e3b95)
- Linux — Linux (4.11)
- Linux — Linux (0)
- Linux — Linux (5.10.248)
- Linux — Linux (5.15.198)
- Linux — Linux (6.1.160)
- Linux — Linux (6.6.120)
- Linux — Linux (6.12.62)
- Linux — Linux (6.17.12)
- Linux — Linux (6.18.1)
- Linux — Linux (6.19)
- Linux — Linux (3.16.44)
- Linux — Linux (3.18.107)
- Linux — Linux (4.4.129)
- Linux — Linux (4.9.14)
- Linux — Linux (4.10.2)

## References

- [CNA](https://git.kernel.org/stable/c/b322bac9f01d03190b5abc52be5d9dd9f22a2b41)
- [CNA](https://git.kernel.org/stable/c/61e03dc3794ebf77a706b85e5a36c9c6d70be6de)
- [CNA](https://git.kernel.org/stable/c/5b266cf6851ce72b11b067fe02adf5a8687104ad)
- [CNA](https://git.kernel.org/stable/c/144c48da33a01d92995aeccd8208eb47d2a8e659)
- [CNA](https://git.kernel.org/stable/c/22a76b0861ae61a299c8e126c1aca8c4fda820fd)
- [CNA](https://git.kernel.org/stable/c/ba8aeff294ac7ff6dfe293663d815c54c5ee218c)
- [CNA](https://git.kernel.org/stable/c/5cad18e527ba8a9ca5463cc170073eeb5a4826f4)
- [CNA](https://git.kernel.org/stable/c/0cd8feea8777f8d9b9a862b89c688b049a5c8475)
- [siemens-SADP](https://cert-portal.siemens.com/productcert/html/ssa-019113.html)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.54%
- **EPSS Percentile:** 43.9

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._