Description: BPF protection against Speculative Store Bypass can be bypassed to disclose arbitrary kernel memory
References:
 https://www.openwall.com/lists/oss-security/2021/08/01/3
 https://lore.kernel.org/stable/20210913153537.2162465-1-ovidiu.panait@windriver.com/
Notes:
 bwh> I think this can be ignored. Privileged users can generally read
 bwh> kernel memory through kprobes/tracepoints. Unprivileged use of
 bwh> eBPF is now disabled by default in all Debian suites.
Bugs:
upstream: released (5.14-rc4) [f5e81d1117501546b7be050c5fbafa6efd2c722c, 2039f26f3aca5b0e419b98f65dd36481337b86ee]
5.10-upstream-stable: released (5.10.56) [bea9e2fd180892eba2574711b05b794f1d0e7b73, 0e9280654aa482088ee6ef3deadef331f5ac5fb0]
4.19-upstream-stable: released (4.19.207) [91cdb5b36234e6af69d6280f1510e4453707a2b8, 872968502114d68c21419cf7eb5ab97717e7b803]
4.9-upstream-stable: needed
sid: released (5.10.46-4) [bugfix/all/bpf-introduce-bpf-nospec-instruction-for-mitigating-.patch, bugfix/all/bpf-fix-leakage-due-to-insufficient-speculative-stor.patch]
5.10-bullseye-security: N/A "Fixed before branching point"
4.19-buster-security: released (4.19.208-1)
4.9-stretch-security: ignored "Too risky to backport, and mitigated by default"