high CVSS 7.1

CVE-2021-47039·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: ataflop: potential out of bounds in do_format() The function uses "type" as an array index: q = unit[drive].disk[type]->queue; Unfortunately the bounds check on "type" isn't done until later in the function. Fix this by moving the bounds check to the start.

Severity
high
Software
Kernel
Fixed in
5.12.4
Published
2024-02-28

Affected versions

From: 5.12

Until: 5.12.4

Fixed in: 5.12.4

How to fix this CVE

Update your Linux kernel to version 5.12.4 or later to patch the out-of-bounds array access vulnerability in the ataflop disk driver. This flaw could allow a local privileged user to trigger memory corruption or denial of service. Kernel updates should be applied immediately followed by a system reboot to take effect.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your current kernel version by running: uname -r
  2. Step 2: Verify if you are affected by checking if your version is between 5.12.0 and 5.12.3: grep VERSION /proc/version
  3. Step 3: Search kernel logs for ataflop-related errors or crashes: sudo dmesg | grep -i ataflop
  4. Step 4: After patching, confirm the new kernel is active: uname -r should show version 5.12.4 or higher

FAQ

What is CVE-2021-47039?

This vulnerability exists in the Linux kernel's ataflop (Atari floppy disk driver) where an array bounds check is performed too late in the do_format() function, allowing an out-of-bounds memory access via the 'type' parameter.

Is CVE-2021-47039 being actively exploited?

No, there is no evidence of active exploitation in the wild, and no public exploits are available for this vulnerability.

What versions of Kernel are affected by CVE-2021-47039?

Linux kernel versions 5.12.0 through 5.12.3 are affected. Version 5.12.4 and later contain the fix.

How do I check if my server is vulnerable to CVE-2021-47039?

Run 'uname -r' and check if the output shows a kernel version between 5.12.0 and 5.12.3; if so, your system is vulnerable and requires a kernel update.

Does Defensia detect CVE-2021-47039?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2021-47039 will appear in your dashboard with remediation steps.

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CVE-2026-64033CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs: Fix use-after-free in path file creation cleanup In the error path of rtrs_srv_create_path_files(), the sysfs root folders may already have been created and srv_path->kobj may already have been initialized. If a later step fails, the cleanup currently calls kobject_put(&srv_path->kobj) before rtrs_srv_destroy_once_sysfs_root_folders(srv_path). kobject_put() may drop the last reference to srv_path->kobj and invoke the release callback, rtrs_srv_release(), which frees srv_path. The following call to rtrs_srv_destroy_once_sysfs_root_folders(srv_path) then dereferences srv_path internally to access srv_path->srv, resulting in a use-after-free. This failure path is reached before rtrs_srv_create_path_files() returns success, so the successful-path lifetime handling is not involved. Fix this by destroying the sysfs root folders before calling kobject_put(&srv_path->kobj), so srv_path is still valid while the helper accesses it. This issue was found by a static analysis tool I am developing.
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References

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