Linux Kernel up to 6.11.5 sync_linked_regs random values

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.11.5 and classified as problematic. This affects the function sync_linked_regs. The manipulation leads to random values. This vulnerability is uniquely identified as CVE-2024-53125. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Linux Kernel up to 6.11.5. This issue affects the function sync_linked_regs. The manipulation with an unknown input leads to a random values vulnerability. Using CWE to declare the problem leads to CWE-330. The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. Impacted is confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: bpf: sync_linked_regs() must preserve subreg_def Range propagation must not affect subreg_def marks, otherwise the following example is rewritten by verifier incorrectly when BPF_F_TEST_RND_HI32 flag is set: 0: call bpf_ktime_get_ns call bpf_ktime_get_ns 1: r0 &= 0x7fffffff after verifier r0 &= 0x7fffffff 2: w1 = w0 rewrites w1 = w0 3: if w0 r11 = 0x2f5674a6 (r) 4: r1 >>= 32 r11 <<= 32 (r) 5: r0 = r1 r1 |= r11 (r) 6: exit; if w0 < 0xa goto pc+0 r1 >>= 32 r0 = r1 exit (or zero extension of w1 at (2) is missing for architectures that require zero extension for upper register half). The following happens w/o this patch: - r0 is marked as not a subreg at (0); - w1 is marked as subreg at (2); - w1 subreg_def is overridden at (3) by copy_register_state(); - w1 is read at (5) but mark_insn_zext() does not mark (2) for zero extension, because w1 subreg_def is not set; - because of BPF_F_TEST_RND_HI32 flag verifier inserts random value for hi32 bits of (2) (marked (r)); - this random value is read at (5).

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2024-53125 since 11/19/2024. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1600.001 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 214250 (SUSE SLES15 / openSUSE 15 Security Update : kernel (SUSE-SU-2025:0117-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.11.6 eliminates this vulnerability. Applying the patch e2ef0f317a52/e9bd9c498cb0 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (214250) and CERT Bund (WID-SEC-2024-3608). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Open Source eCryptfs
• Dell NetWorker
• Dell Avamar

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.11.0
• 6.11.1
• 6.11.2
• 6.11.3
• 6.11.4
• 6.11.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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