CVE-2024-44942

2024-08-2612:15:06

Linux

web.nvd.nist.gov

linux kernel

vulnerability

resolution

f2fs

inline data

inode

sanity check

CVSS3

7.8

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

AI Score

6.4

Confidence

Low

EPSS

Percentile

5.0%

JSON

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

f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC

syzbot reports a f2fs bug as below:

------------[ cut here ]------------
kernel BUG at fs/f2fs/inline.c:258!
CPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0
RIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258
Call Trace:
f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834
f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline]
__f2fs_write_data_pages fs/f2fs/data.c:3288 [inline]
f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315
do_writepages+0x35b/0x870 mm/page-writeback.c:2612
__writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650
writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941
wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117
wb_do_writeback fs/fs-writeback.c:2264 [inline]
wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f2/0x390 kernel/kthread.c:388
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The root cause is: inline_data inode can be fuzzed, so that there may
be valid blkaddr in its direct node, once f2fs triggers background GC
to migrate the block, it will hit f2fs_bug_on() during dirty page
writeback.

Let’s add sanity check on F2FS_INLINE_DATA flag in inode during GC,
so that, it can forbid migrating inline_data inode’s data block for
fixing.

Affected configurations

Nvd

Vulners

Node

linuxlinux_kernelRange<6.6.47

linuxlinux_kernelRange6.7–6.10.6

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/f2fs/gc.c"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "ae00e6536a2d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "26c07775fb5d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "fc01008c92f4",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/f2fs/gc.c"
    ],
    "versions": [
      {
        "version": "6.6.47",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10.6",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]