CVE-2026-53095
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A vulnerability in the Linux kernel regarding abuse of kprobe_write_ctx via freplace programs. Uprobe programs can modify struct pt_regs, and through kprobe+freplace they can affect kernel function arguments. The fix disallows attaching freplace programs to kprobe with different kprobe_write_ctx values.
Risk Assessment
The risk involves potential modification of kernel function arguments by unauthorized BPF programs, which could compromise system integrity.
Recommendation
Update the Linux kernel to a patched version and restrict permissions for loading BPF programs.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix abuse of kprobe_write_ctx via freplace uprobe programs are allowed to modify struct pt_regs. Since the actual program type of uprobe is KPROBE, it can be abused to modify struct pt_regs via kprobe+freplace when the kprobe attaches to kernel functions. For example, SEC("?kprobe") int kprobe(struct pt_regs *regs) { return 0; } SEC("?freplace") int freplace_kprobe(struct pt_regs *regs) { regs->di = 0; return 0; } freplace_kprobe prog will attach to kprobe prog. kprobe prog will attach to a kernel function. Without this patch, when the kernel function runs, its first arg will always be set as 0 via the freplace_kprobe prog. To fix the abuse of kprobe_write_ctx=true via kprobe+freplace, disallow attaching freplace programs on kprobe programs with different kprobe_write_ctx values.