| Message ID | c3fee3c8-c808-e2ae-b885-d24e785989f6@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | libxl: slightly correct JSON generation of CPU policy | expand |
On Tue, Aug 15, 2023 at 02:35:55PM +0200, Jan Beulich wrote: > The "cpuid_empty" label is also (in principle; maybe only for rubbish > input) reachable in the "cpuid_only" case. Hence the label needs to live > ahead of the check of the variable. > > Fixes: 5b80cecb747b ("libxl: introduce MSR data in libxl_cpuid_policy") > Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Thanks,
On 15/08/2023 3:26 pm, Anthony PERARD wrote: > On Tue, Aug 15, 2023 at 02:35:55PM +0200, Jan Beulich wrote: >> The "cpuid_empty" label is also (in principle; maybe only for rubbish >> input) reachable in the "cpuid_only" case. Hence the label needs to live >> ahead of the check of the variable. >> >> Fixes: 5b80cecb747b ("libxl: introduce MSR data in libxl_cpuid_policy") >> Signed-off-by: Jan Beulich <jbeulich@suse.com> > Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> Hmm - this was included in the security backports. I guess it ought to go back to 4.15 (now that 4.14 is properly dead). ~Andrew
On 15.08.2023 16:28, Andrew Cooper wrote: > On 15/08/2023 3:26 pm, Anthony PERARD wrote: >> On Tue, Aug 15, 2023 at 02:35:55PM +0200, Jan Beulich wrote: >>> The "cpuid_empty" label is also (in principle; maybe only for rubbish >>> input) reachable in the "cpuid_only" case. Hence the label needs to live >>> ahead of the check of the variable. >>> >>> Fixes: 5b80cecb747b ("libxl: introduce MSR data in libxl_cpuid_policy") >>> Signed-off-by: Jan Beulich <jbeulich@suse.com> >> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> > > Hmm - this was included in the security backports. I guess it ought to > go back to 4.15 (now that 4.14 is properly dead). Depends on whether this is just a theoretical issue, I would say. Can legacy format input legitimately be empty? If not, I wouldn't bother putting this onto the security-only branches. (Guess how I found it. For the 4.13 backport much of this needed quite a bit of adjustment. Pulling in more stuff from 4.14 isn't really an option, not the least since I will need to [at least try to] go further back.) Jan
On Tue, Aug 15, 2023 at 04:44:57PM +0200, Jan Beulich wrote: > On 15.08.2023 16:28, Andrew Cooper wrote: > > On 15/08/2023 3:26 pm, Anthony PERARD wrote: > >> On Tue, Aug 15, 2023 at 02:35:55PM +0200, Jan Beulich wrote: > >>> The "cpuid_empty" label is also (in principle; maybe only for rubbish > >>> input) reachable in the "cpuid_only" case. Hence the label needs to live > >>> ahead of the check of the variable. > >>> > >>> Fixes: 5b80cecb747b ("libxl: introduce MSR data in libxl_cpuid_policy") > >>> Signed-off-by: Jan Beulich <jbeulich@suse.com> > >> Reviewed-by: Anthony PERARD <anthony.perard@citrix.com> > > > > Hmm - this was included in the security backports. I guess it ought to > > go back to 4.15 (now that 4.14 is properly dead). > > Depends on whether this is just a theoretical issue, I would say. Can > legacy format input legitimately be empty? If not, I wouldn't bother > putting this onto the security-only branches. I don't think libxl would generate an empty array. libxl calls libxl__cpuid_policy_is_empty() before calling libxl_cpuid_policy_list_gen_json(), so no empty array. Then, without this fix, I think it would just mean that libxl would return an error on something that was ok to do before. So backporting the patch would be a nice to have.
--- a/tools/libs/light/libxl_cpuid.c +++ b/tools/libs/light/libxl_cpuid.c @@ -710,10 +710,11 @@ parse_cpuid: libxl__strdup(NOGC, libxl__json_object_get_string(r)); } } + +cpuid_empty: if (cpuid_only) return 0; -cpuid_empty: co = libxl__json_map_get("msr", o, JSON_ARRAY); if (!libxl__json_object_is_array(co)) return ERROR_FAIL;
The "cpuid_empty" label is also (in principle; maybe only for rubbish input) reachable in the "cpuid_only" case. Hence the label needs to live ahead of the check of the variable. Fixes: 5b80cecb747b ("libxl: introduce MSR data in libxl_cpuid_policy") Signed-off-by: Jan Beulich <jbeulich@suse.com>