Linux Kernel up to 6.12.24 filter.c bpf_skb_pull_data state issue

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.24. It has been rated as problematic. Impacted is the function bpf_skb_pull_data of the file filter.c. The manipulation leads to state issue. This vulnerability is listed as CVE-2024-58098. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Linux Kernel up to 6.12.24. This issue affects the function bpf_skb_pull_data of the file filter.c. The manipulation with an unknown input leads to a state issue vulnerability. Using CWE to declare the problem leads to CWE-371. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: bpf: track changes_pkt_data property for global functions When processing calls to certain helpers, verifier invalidates all packet pointers in a current state. For example, consider the following program: __attribute__((__noinline__)) long skb_pull_data(struct __sk_buff *sk, __u32 len) { return bpf_skb_pull_data(sk, len); } SEC("tc") int test_invalidate_checks(struct __sk_buff *sk) { int *p = (void *)(long)sk->data; if ((void *)(p + 1) > (void *)(long)sk->data_end) return TCX_DROP; skb_pull_data(sk, 0); *p = 42; return TCX_PASS; } After a call to bpf_skb_pull_data() the pointer 'p' can't be used safely. See function filter.c:bpf_helper_changes_pkt_data() for a list of such helpers. At the moment verifier invalidates packet pointers when processing helper function calls, and does not traverse global sub-programs when processing calls to global sub-programs. This means that calls to helpers done from global sub-programs do not invalidate pointers in the caller state. E.g. the program above is unsafe, but is not rejected by verifier. This commit fixes the omission by computing field bpf_subprog_info->changes_pkt_data for each sub-program before main verification pass. changes_pkt_data should be set if: - subprogram calls helper for which bpf_helper_changes_pkt_data returns true; - subprogram calls a global function, for which bpf_subprog_info->changes_pkt_data should be set. The verifier.c:check_cfg() pass is modified to compute this information. The commit relies on depth first instruction traversal done by check_cfg() and absence of recursive function calls: - check_cfg() would eventually visit every call to subprogram S in a state when S is fully explored; - when S is fully explored: - every direct helper call within S is explored (and thus changes_pkt_data is set if needed); - every call to subprogram S1 called by S was visited with S1 fully explored (and thus S inherits changes_pkt_data from S1). The downside of such approach is that dead code elimination is not taken into account: if a helper call inside global function is dead because of current configuration, verifier would conservatively assume that the call occurs for the purpose of the changes_pkt_data computation.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2024-58098 since 03/06/2025. The exploitation is known to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/10/2025).

The vulnerability scanner Nessus provides a plugin with the ID 249192 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-1993)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.25 eliminates this vulnerability. Applying the patch 1d572c60488b52882b719ed273767ee3b280413d/51081a3f25c742da5a659d7fc6fd77ebfdd555be 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 vulnerability database at Tenable (249192). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24

License

• open-source

Website

• Vendor: https://www.kernel.org/

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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