On Wed, Mar 04, 2020 at 09:47:02AM +0100, Greg Kroah-Hartman wrote: > On Wed, Mar 04, 2020 at 09:11:28AM +0100, Greg Kroah-Hartman wrote: > > On Wed, Mar 04, 2020 at 12:43:42PM +0530, Naresh Kamboju wrote: > > > On Tue, 3 Mar 2020 at 23:16, Greg Kroah-Hartman > > > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > This is the start of the stable review cycle for the 5.5.8 release. > > > > There are 176 patches in this series, all will be posted as a response > > > > to this one. If anyone has any issues with these being applied, please > > > > let me know. > > > > > > > > Responses should be made by Thu, 05 Mar 2020 17:42:06 +0000. > > > > Anything received after that time might be too late. > > > > > > > > The whole patch series can be found in one patch at: > > > > https://www.kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.5.8-rc1.gz > > > > or in the git tree and branch at: > > > > git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.5.y > > > > and the diffstat can be found below. > > > > > > > > thanks, > > > > > > > > greg k-h > > > > > > > > > > Results from Linaro’s test farm. > > > Regressions detected on x86_64 and i386. > > > > > > Test failure output: > > > CVE-2017-5715: VULN (IBRS+IBPB or retpoline+IBPB+RSB filling, is > > > needed to mitigate the vulnerability) > > > > > > Test description: > > > CVE-2017-5715 branch target injection (Spectre Variant 2) > > > > > > Impact: Kernel > > > Mitigation 1: new opcode via microcode update that should be used by > > > up to date compilers to protect the BTB (by flushing indirect branch > > > predictors) > > > Mitigation 2: introducing "retpoline" into compilers, and recompile > > > software/OS with it > > > Performance impact of the mitigation: high for mitigation 1, medium > > > for mitigation 2, depending on your CPU > > > > So these are regressions or just new tests? > > > > If regressions, can you do 'git bisect' to find the offending commit? > > > > Also, are you sure you have an updated microcode on these machines and a > > proper compiler for retpoline? > > As an example of just how crazy that script is, here's the output of my > machine for that first CVE issue: > > CVE-2017-5715 aka 'Spectre Variant 2, branch target injection' > * Mitigated according to the /sys interface: YES (Mitigation: Full generic retpoline, IBPB: conditional, IBRS_FW, STIBP: conditional, RSB filling) > * Mitigation 1 > * Kernel is compiled with IBRS support: YES > * IBRS enabled and active: YES (for firmware code only) > * Kernel is compiled with IBPB support: YES > * IBPB enabled and active: YES > * Mitigation 2 > * Kernel has branch predictor hardening (arm): NO > * Kernel compiled with retpoline option: YES > * Kernel compiled with a retpoline-aware compiler: YES (kernel reports full retpoline compilation) > * Kernel supports RSB filling: UNKNOWN (couldn't check (couldn't find your kernel image in /boot, if you used netboot, this is normal)) > > STATUS: VULNERABLE (IBRS+IBPB or retpoline+IBPB+RSB filling, is needed to mitigate > > So why is this "Vulnerable"? Because it didn't think it could find my > kernel image for some odd reason, despite it really being in /boot/ (I > don't use netboot) > > So please verify that this really is a real issue, and not just the > script doing foolish things. And, if I tell the script where my kernel image is, suddenly all is good: CVE-2017-5715 aka 'Spectre Variant 2, branch target injection' * Mitigation 1 * Kernel is compiled with IBRS support: YES * IBRS enabled and active: N/A (not testable in offline mode) * Kernel is compiled with IBPB support: YES * IBPB enabled and active: N/A (not testable in offline mode) * Mitigation 2 * Kernel has branch predictor hardening (arm): UNKNOWN * Kernel compiled with retpoline option: UNKNOWN (couldn't read your kernel configuration) * Kernel supports RSB filling: YES > STATUS: NOT VULNERABLE (offline mode: kernel supports IBRS + IBPB to mitigate the vulnerability)
