[add security & dhowells] On 11/13/23 18:23, Kelvie Wong wrote: > This allows the user to tell the kernel that they know better (namely, > they secured their swap properly), and that it can enable hibernation. > > I've been using this for about a year now, as it doesn't seem like > proper secure hibernation was going to be implemented back then, and > it's now been a year since I've been building my own kernels with this > patch, so getting this upstreamed would save some CO2 from me building > my own kernels every upgrade. > > Some other not-me users have also tested the patch: > > https://community.frame.work/t/guide-fedora-36-hibernation-with-enabled-secure-boot-and-full-disk-encryption-fde-decrypting-over-tpm2/25474/17 > > Signed-off-by: Kelvie Wong <kelvie@xxxxxxxxx> > --- > Documentation/admin-guide/kernel-parameters.txt | 5 +++++ > kernel/power/hibernate.c | 10 +++++++++- > 2 files changed, 14 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 426fa892d311..54785faba9e0 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2804,6 +2804,11 @@ > to extract confidential information from the kernel > are also disabled. > > + lockdown_hibernate [HIBERNATION] > + Enable hibernation even if lockdown is enabled. Enable this only if > + your swap is encrypted and secured properly, as an attacker can > + modify the kernel offline during hibernation. > + > locktorture.nreaders_stress= [KNL] > Set the number of locking read-acquisition kthreads. > Defaults to being automatically set based on the > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c > index 89c71fce225d..2221c531d54c 100644 > --- a/kernel/power/hibernate.c > +++ b/kernel/power/hibernate.c > @@ -36,6 +36,7 @@ > #include "power.h" > > > +static int lockdown_hibernate; > static int nocompress; > static int noresume; > static int nohibernate; > @@ -82,7 +83,7 @@ void hibernate_release(void) > bool hibernation_available(void) > { > return nohibernate == 0 && > - !security_locked_down(LOCKDOWN_HIBERNATION) && > + (lockdown_hibernate || !security_locked_down(LOCKDOWN_HIBERNATION)) && > !secretmem_active() && !cxl_mem_active(); > } > > @@ -1340,6 +1341,12 @@ static int __init nohibernate_setup(char *str) > return 1; > } > > +static int __init lockdown_hibernate_setup(char *str) > +{ > + lockdown_hibernate = 1; > + return 1; > +} > + > __setup("noresume", noresume_setup); > __setup("resume_offset=", resume_offset_setup); > __setup("resume=", resume_setup); > @@ -1347,3 +1354,4 @@ __setup("hibernate=", hibernate_setup); > __setup("resumewait", resumewait_setup); > __setup("resumedelay=", resumedelay_setup); > __setup("nohibernate", nohibernate_setup); > +__setup("lockdown_hibernate", lockdown_hibernate_setup); -- ~Randy
