FAILED: patch "[PATCH] arm64: proton-pack: Include unprivileged eBPF status in" failed to apply to 5.4-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 58c9a5060cb7cd529d49c93954cdafe81c1d642a Mon Sep 17 00:00:00 2001
From: James Morse <[email protected]>
Date: Thu, 3 Mar 2022 16:53:56 +0000
Subject: [PATCH] arm64: proton-pack: Include unprivileged eBPF status in
Spectre v2 mitigation reporting
The mitigations for Spectre-BHB are only applied when an exception is taken from user-space. The mitigation status is reported via the spectre_v2 sysfs vulnerabilities file.
When unprivileged eBPF is enabled the mitigation in the exception vectors can be avoided by an eBPF program.
When unprivileged eBPF is enabled, print a warning and report vulnerable via the sysfs vulnerabilities file.
arch/arm64/kernel/proton-pack.c +26 -0
@@ -18,6 +18,7 @@*/ #include <linux/arm-smccc.h> +#include <linux/bpf.h> #include <linux/cpu.h> #include <linux/device.h> #include <linux/nospec.h>
@@ -111,6 +112,15 @@ static const char *get_bhb_affected_string(enum mitigation_state bhb_state) } } +static bool _unprivileged_ebpf_enabled (void ) +{ +#ifdef CONFIG_BPF_SYSCALL +return !sysctl_unprivileged_bpf_disabled; +#else +return false; +#endif +} +ssize_t cpu_show_spectre_v2 (struct device *dev,struct device_attribute *attr,char *buf) {
@@ -130,6 +140,9 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, v2_str ="CSV2" ; fallthrough;case SPECTRE_MITIGATED : +if (bhb_state ==SPECTRE_MITIGATED &&_unprivileged_ebpf_enabled ()) +return sprintf (buf,"Vulnerable: Unprivileged eBPF enabled\n" ); +return sprintf (buf,"Mitigation: %s%s\n" , v2_str, bhb_str);case SPECTRE_VULNERABLE : fallthrough;
@@ -1125,3 +1138,16 @@ void __init spectre_bhb_patch_clearbhb(struct alt_instr *alt, *updptr++ =cpu_to_le32 (aarch64_insn_gen_nop ()); *updptr++ =cpu_to_le32 (aarch64_insn_gen_nop ()); } + +#ifdef CONFIG_BPF_SYSCALL +#define EBPF_WARN "Unprivileged eBPF is enabled, data leaks possible via Spectre v2 BHB attacks!\n" +void unpriv_ebpf_notify (int new_state) +{ +if (spectre_v2_state ==SPECTRE_VULNERABLE || + spectre_bhb_state !=SPECTRE_MITIGATED ) +return ; + +if (!new_state) +pr_err ("WARNING: %s" ,EBPF_WARN ); +} +#endif
Hi Greg,
arch/arm64/kernel/proton-pack.c
Quoted 28 lines · On 09/03/2022 12:05, [email protected] wrote:
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.------------------ original commit in Linus's tree ------------------
From
58c9a5060cb7cd529d49c93954cdafe81c1d642aMon Sep 17 00:00:00 2001
From: James Morse <[email protected]>
Date: Thu, 3 Mar 2022 16:53:56 +0000
Subject: [PATCH] arm64: proton-pack: Include unprivileged eBPF status in
Spectre v2 mitigation reportingThe mitigations for Spectre-BHB are only applied when an exception is taken from user-space. The mitigation status is reported via the
spectre_v2sysfs vulnerabilities file.When unprivileged eBPF is enabled the mitigation in the exception vectors can be avoided by an eBPF program.
When unprivileged eBPF is enabled, print a warning and report vulnerable via the sysfs vulnerabilities file.
arch/arm64/kernel/proton-pack.c +0
-0
Yup, this far back the code lives in cpu_errata.c, as it hadn't been centralised. I'll look at what is involved in backporting the whole lot...
Thanks,
James