CVE-2022-50546 — linux / linux_kernel
Use of Uninitialized ResourceIn 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()'.
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 5.15.61 | 5.15.87 |
| linux / linux_kernel | 5.18.18 | 5.19 |
| linux / linux_kernel | 5.19.2 | 6.0.18 |
| linux / linux_kernel | 6.1 | 6.1.4 |
| linux / linux_kernel | 5.10.163 | 5.10.163.x |
- https://git.kernel.org/stable/c/091f85db4c3fb1734a6d7fb4777a2b2831da6631
- https://git.kernel.org/stable/c/3c31d8d3ad95aef8cc17a4fcf317e46217148439
- https://git.kernel.org/stable/c/56491d60ddca9c697d885394cb0173675b9ab81f
- https://git.kernel.org/stable/c/7ea71af94eaaaf6d9aed24bc94a05b977a741cb9
- https://git.kernel.org/stable/c/9f966e021c20caae639dd0e404c8761e8281a2c4
- https://git.kernel.org/stable/c/e431b4fb1fb8c2654b808086e9747a000adb9655
- https://git.kernel.org/stable/c/f0bffdcc7cb14598af2aa706f1e0f2a9054154ba
Deep Security Visibility Without the Complexity
SynScan provides clear, real-time security insights so you can monitor your attack surface, spot risks early, and act fast—without extra complexity.
- No setup fees
- 5-min deployment
- Cancel anytime
Frequently Asked Questions
A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.
CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.
A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.
Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.
Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.
SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.