Linux KernelOperating system · Linux
CVE-2024-56755
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: netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING In fscache_create_volume(), there is a missing memory barrier between the bit-clearing operation and the wake-up operation. This may cause a situation where, after a wake-up, the bit-clearing operation hasn't been detected yet, leading to an indefinite wait. The triggering process is as follows: [cookie1] [cookie2] [volume_work] fscache_perform_lookup fscache_create_volume fscache_perform_lookup fscache_create_volume fscache_create_volume_work cachefiles_acquire_volume clear_and_wake_up_bit test_and_set_bit test_and_set_bit goto maybe_wait goto no_wait In the above process, cookie1 and cookie2 has the same volume. When cookie1 enters the -no_wait- process, it will clear the bit and wake up the waiting process. If a barrier is missing, it may cause cookie2 to remain in the -wait- process indefinitely. In commit 3288666c7256 ("fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work()"), barriers were added to similar operations in fscache_create_volume_work(), but fscache_create_volume() was missed. By combining the clear and wake operations into clear_and_wake_up_bit() to fix this issue.
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 analysisAllocated memory is never released on some path, so a long-running service or a repeatedly triggered request steadily consumes memory until performance degrades or the process crashes. Attackers exploit it by simply driving the leaking path. Remediation is pairing every allocation with a release and using ownership patterns or tooling to catch what leaks.
General guidance for the memory leak 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
>= 5.17, < 6.1.120>= 6.2, < 6.6.64>= 6.7, < 6.11.11>= 6.12, < 6.12.2CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 · scoped6.1.1206.6.646.11.11
Linux Kernel 6.1.120+ / 6.6.64+ / 6.11.11+ / 6.12.2+ (depending on which major version branch you are on)
- Identify the current running kernel version using `uname -r`
- Determine which version range your current kernel falls into (6.1.x, 6.2-6.6.x, 6.7-6.11.x, or 6.12.x)
- Upgrade to a fixed kernel version: for 6.1.x series upgrade to 6.1.120 or later; for 6.2-6.6.x series upgrade to 6.6.64 or later; for 6.7-6.11.x series upgrade to 6.11.11 or later; for 6.12.x series upgrade to 6.12.2 or later
- Apply the upgrade via your distribution's package manager (e.g., `apt-get dist-upgrade`, `yum update`, or `dnf upgrade`)
- Reboot the system to load the fixed kernel
- Verify the fix is applied by checking the kernel version matches or exceeds the fixed version
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-2024-56755 — 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-2024-56755 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
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- Version or environment caveats, and links to real fixes
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