CVE-2023-52928
bpf: Skip invalid kfunc call in backtrack_insn
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bpf: Skip invalid kfunc call in backtrack_insn
In the Linux kernel, the following vulnerability has been resolved: bpf: Skip invalid kfunc call in backtrack_insn The verifier skips invalid kfunc call in check_kfunc_call(), which would be captured in fixup_kfunc_call() if such insn is not eliminated by dead code elimination. However, this can lead to the following warning in backtrack_insn(), also see [1]: ------------[ cut here ]------------ verifier backtracking bug WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn kernel/bpf/verifier.c:2756 __mark_chain_precision kernel/bpf/verifier.c:3065 mark_chain_precision kernel/bpf/verifier.c:3165 adjust_reg_min_max_vals kernel/bpf/verifier.c:10715 check_alu_op kernel/bpf/verifier.c:10928 do_check kernel/bpf/verifier.c:13821 [inline] do_check_common kernel/bpf/verifier.c:16289 [...] So make backtracking conservative with this by returning ENOTSUPP. [1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/
Reserved 2024-08-21 | Published 2025-03-27 | Updated 2025-05-04 | Assigner Linuxgit.kernel.org/...c/6e2fac197de2c4c041bdd8982cffb104689113f1
git.kernel.org/...c/74eec8266f37aff609db6a2f2b093e56a11c28c4
git.kernel.org/...c/d3178e8a434b58678d99257c0387810a24042fb6
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