# CVE-2022-50546: ext4: fix uninititialized value in 'ext4_evict_inode'

> A local attacker can trigger an uninitialized value bug in the ext4 filesystem to potentially disclose sensitive kernel memory contents.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 7 Oct 2025
- **Updated:** 23 May 2026
- **Also known as:** DEBIAN-CVE-2022-50546, GHSA-g2jp-ch4j-rcfr, UBUNTU-CVE-2022-50546

## What is CVE-2022-50546?

CVE-2022-50546 is a high-severity vulnerability in Linux kernel, published on 7 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

ext4: fix uninititialized value in 'ext4_evict_inode'

Syzbot found the following issue:
=====================================================
BUG: KMSAN: uninit-value in ext4_evict_inode+0xdd/0x26b0 fs/ext4/inode.c:180
 ext4_evict_inode+0xdd/0x26b0 fs/ext4/inode.c:180
 evict+0x365/0x9a0 fs/inode.c:664
 iput_final fs/inode.c:1747 [inline]
 iput+0x985/0xdd0 fs/inode.c:1773
 __ext4_new_inode+0xe54/0x7ec0 fs/ext4/ialloc.c:1361
 ext4_mknod+0x376/0x840 fs/ext4/namei.c:2844
 vfs_mknod+0x79d/0x830 fs/namei.c:3914
 do_mknodat+0x47d/0xaa0
 __do_sys_mknodat fs/namei.c:3992 [inline]
 __se_sys_mknodat fs/namei.c:3989 [inline]
 __ia32_sys_mknodat+0xeb/0x150 fs/namei.c:3989
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 __alloc_pages+0x9f1/0xe80 mm/page_alloc.c:5578
 alloc_pages+0xaae/0xd80 mm/mempolicy.c:2285
 alloc_slab_page mm/slub.c:1794 [inline]
 allocate_slab+0x1b5/0x1010 mm/slub.c:1939
 new_slab mm/slub.c:1992 [inline]
 ___slab_alloc+0x10c3/0x2d60 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc_lru+0x6f3/0xb30 mm/slub.c:3429
 alloc_inode_sb include/linux/fs.h:3117 [inline]
 ext4_alloc_inode+0x5f/0x860 fs/ext4/super.c:1321
 alloc_inode+0x83/0x440 fs/inode.c:259
 new_inode_pseudo fs/inode.c:1018 [inline]
 new_inode+0x3b/0x430 fs/inode.c:1046
 __ext4_new_inode+0x2a7/0x7ec0 fs/ext4/ialloc.c:959
 ext4_mkdir+0x4d5/0x1560 fs/ext4/namei.c:2992
 vfs_mkdir+0x62a/0x870 fs/namei.c:4035
 do_mkdirat+0x466/0x7b0 fs/namei.c:4060
 __do_sys_mkdirat fs/namei.c:4075 [inline]
 __se_sys_mkdirat fs/namei.c:4073 [inline]
 __ia32_sys_mkdirat+0xc4/0x120 fs/namei.c:4073
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1b/0x20 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

CPU: 1 PID: 4625 Comm: syz-executor.2 Not tainted 6.1.0-rc4-syzkaller-62821-gcb231e2f67ec #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
=====================================================

Now, 'ext4_alloc_inode()' didn't init 'ei->i_flags'. If new inode failed
before set 'ei->i_flags' in '__ext4_new_inode()', then do 'iput()'. As after
6bc0d63dad7f commit will access 'ei->i_flags' in 'ext4_evict_inode()' which
will lead to access uninit-value.
To solve above issue just init 'ei->i_flags' in 'ext4_alloc_inode()'.

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2022-50546?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-50546?

Apply the vendor's patch.

## Is CVE-2022-50546 being exploited?

There is no known exploitation of CVE-2022-50546 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50546 and fix it if it is affected.

What it is: CVE-2022-50546 is a high-severity vulnerability in Linux kernel, published on 7 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-50546 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-50546/ (Markdown: https://insights.sbomify.com/CVE-2022-50546/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50546
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50546
- OSV: https://osv.dev/vulnerability/CVE-2022-50546

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50546/
Summaries are generated and may contain mistakes; the official description above is the record.
