A recent Linux kernel vulnerability, identified as CVE-2023-52602, has been discovered and resolved. This issue pertained to an out-of-bounds read in the dtSearch function of the jfs filesystem (IBM's Journaling File System).

Vulnerability Details

This vulnerability originates from a lack of bound checks while searching for the current page in the sorted entry table of the page. As a result, an out-of-bounds access could occur in the dtSearch function.

Such an out-of-bounds read could potentially lead to data leaks, unauthorized data modification, or even a system crash. To address this issue, proper bound checks have been added in the latest Linux kernel patch.

The following code snippet demonstrates the added bound checks in the patch

-   if (dtFind(cmp, &f))
-       bp = read_index(sid, p, &rc);
-   else
-       rc = -EIO;

+   if (p < DT_USEDFREE(len))
+   {
+       if (dtFind(cmp, &f))
+           bp = read_index(sid, p, &rc);
+       else
+           rc = -EIO;
+   }
+   else
+   {
+       rc = -ERANGE;
+   }

In the above code snippet, a conditional check has been added to ensure that p (the page being searched) falls within the valid range before performing any further operations. If it does not fall within the valid range, the function will return an -ERANGE error code.

Jfs Commit that fixes the issue

[https://git.kernel.org/pub/scm/fs/jfs/jfs-2.4.git/commit/?id=d6a057173dbe437c7d23d5a408150b1c8cbb3db2]

Patch Detail on Linux Kernel Mailing List

[https://lkml.org/lkml/2021/6/3/839]

Exploit Details

While there are currently no known exploits for this vulnerability, ensuring that your Linux system is running the latest kernel version will help protect against any future exploits that might attempt to target the issue fixed by this patch.

Recommendations

To safeguard your system from potential threats exploiting this vulnerability, it is recommended that you:

Update to the latest available kernel version for your Linux distribution.

2. Regularly monitor and patch all system components to identify and address other potential vulnerabilities.

Conclusion

In conclusion, the CVE-2023-52602 vulnerability has been identified and resolved in the Linux kernel. By adding proper bounds checks to the dtSearch function in the jfs filesystem, the potential risks associated with an out-of-bounds read have been mitigated. As always, keeping your system up-to-date is critical to ensuring optimal security against future threats.

Timeline

Published on: 03/06/2024 07:15:10 UTC
Last modified on: 08/01/2024 13:45:40 UTC