Vulnerabilities

Vulnerability · CVE-2024-58098

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 inv

Published May 5, 2025 · catalog updated Oct 15, 2026 · Linux Linux

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CVE-2024-58098 is not in CISA KEV. FIRST estimates a 20.00% chance of exploitation in the next 30 days. Check whether you run Linux Linux.

Severity

High7.8

Known exploitation

Not in CISA/VulnCheck KEV

EPSS

20.00%

Remediation

Version ranges on file

Affected products

cpe linux/linux kernel · vendor Linux Linux 51c39bb1d5d105a02e29aa7960f0a395086e6342 <51081a3f25c742da5a659d7fc6fd77ebfdd555be

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).