Linux KernelOperating system · Linux
CVE-2022-49058
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: cifs: potential buffer overflow in handling symlinks Smatch printed a warning: arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error: __memcpy() 'dctx->buf' too small (16 vs u32max) It's caused because Smatch marks 'link_len' as untrusted since it comes from sscanf(). Add a check to ensure that 'link_len' is not larger than the size of the 'link_str' buffer.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisA fixed-size buffer is filled without checking the length of the incoming data, so it overflows into neighbouring memory. This is the classic overflow attackers use to overwrite return addresses and hijack execution. The fix is strict length checks and safe, bounded string and memory functions.
General guidance for the classic buffer overflow class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Linux KernelOperating system
>= 2.6.37, < 4.9.311>= 4.10, < 4.14.276>= 4.15, < 4.19.239>= 4.20, < 5.4.190>= 5.5, < 5.10.112>= 5.11, < 5.15.35>= 5.16, < 5.17.4= 5.18CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.9.3114.14.2764.19.239
Linux kernel 4.9.311, 4.14.276, 4.19.239, or 5.4.190 (or any later stable release)
- Identify the currently running Linux kernel version using 'uname -r'
- Determine which version branch your current kernel belongs to (4.9.x, 4.14.x, 4.19.x, or 5.4.x)
- Obtain and install a kernel version with the security fix: upgrade to 4.9.311 or later for 4.9.x systems, 4.14.276 or later for 4.14.x systems, 4.19.239 or later for 4.19.x systems, or 5.4.190 or later for 5.4.x systems
- Use your distribution's package manager (apt, yum, dnf) or compile from source to apply the updated kernel
- Reboot the system to load the patched kernel
- Verify the fix is applied by checking the kernel version and confirming the CIFS symlink handling code includes the bounds check
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-49058 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-49058 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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