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| author | Yauheni Kaliuta <ykaliuta@redhat.com> | 2022-09-05 12:01:49 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-09-16 22:11:57 +0200 |
| commit | bfeb7e399bacae4ee46ad978f5fce3e47f0978d6 (patch) | |
| tree | 0ee3057e1cda838babe5b1fcbe198c3fa377f3b1 | |
| parent | a02c118ee9e898612cbae42121b9e8663455b515 (diff) | |
| download | lwn-bfeb7e399bacae4ee46ad978f5fce3e47f0978d6.tar.gz lwn-bfeb7e399bacae4ee46ad978f5fce3e47f0978d6.zip | |
bpf: Use bpf_capable() instead of CAP_SYS_ADMIN for blinding decision
The full CAP_SYS_ADMIN requirement for blinding looks too strict nowadays.
These days given unprivileged BPF is disabled by default, the main users
for constant blinding coming from unprivileged in particular via cBPF -> eBPF
migration (e.g. old-style socket filters).
Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220831090655.156434-1-ykaliuta@redhat.com
Link: https://lore.kernel.org/bpf/20220905090149.61221-1-ykaliuta@redhat.com
| -rw-r--r-- | Documentation/admin-guide/sysctl/net.rst | 3 | ||||
| -rw-r--r-- | include/linux/filter.h | 2 |
2 files changed, 4 insertions, 1 deletions
diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 555681ef6195..6394f5dc2303 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -102,6 +102,9 @@ Values: - 1 - enable JIT hardening for unprivileged users only - 2 - enable JIT hardening for all users +where "privileged user" in this context means a process having +CAP_BPF or CAP_SYS_ADMIN in the root user name space. + bpf_jit_kallsyms ---------------- diff --git a/include/linux/filter.h b/include/linux/filter.h index 527ae1d64e27..75335432fcbc 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -1099,7 +1099,7 @@ static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog) return false; if (!bpf_jit_harden) return false; - if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN)) + if (bpf_jit_harden == 1 && bpf_capable()) return false; return true; |