Hi Miroslav, On 1/11/21 12:30 PM, mreza...@redhat.com wrote: > From: Miroslav Rezanina <mreza...@redhat.com> > > There are two cases when vm name is copied but closing \0 can be lost > in case name is too long (>=256 characters). > > Updating length to copy so there is space for closing \0. > > Signed-off-by: Miroslav Rezanina <mreza...@redhat.com> > --- > target/s390x/kvm.c | 2 +- > target/s390x/misc_helper.c | 4 +++- > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > index b8385e6b95..2313b5727e 100644 > --- a/target/s390x/kvm.c > +++ b/target/s390x/kvm.c > @@ -1918,7 +1918,7 @@ static void insert_stsi_3_2_2(S390CPU *cpu, __u64 addr, > uint8_t ar) > */ > if (qemu_name) { > strncpy((char *)sysib.ext_names[0], qemu_name, > - sizeof(sysib.ext_names[0])); > + sizeof(sysib.ext_names[0]) - 1); > } else { > strcpy((char *)sysib.ext_names[0], "KVMguest"); > }
What about using strpadcpy() instead? strpadcpy((char *)sysib.sysib_322.ext_names[0], sizeof(sysib.sysib_322.ext_names[0]), qemu_name ?: "KVMguest", '\0'); > diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c > index 58dbc023eb..7c478b9e58 100644 > --- a/target/s390x/misc_helper.c > +++ b/target/s390x/misc_helper.c > @@ -369,8 +369,10 @@ uint32_t HELPER(stsi)(CPUS390XState *env, uint64_t a0, > uint64_t r0, uint64_t r1) > ebcdic_put(sysib.sysib_322.vm[0].name, qemu_name, > MIN(sizeof(sysib.sysib_322.vm[0].name), > strlen(qemu_name))); > + memset((char *)sysib.sysib_322.ext_names[0], 0, > + sizeof(sysib.sysib_322.ext_names[0])); > strncpy((char *)sysib.sysib_322.ext_names[0], qemu_name, > - sizeof(sysib.sysib_322.ext_names[0])); > + sizeof(sysib.sysib_322.ext_names[0]) - 1); And here: strpadcpy((char *)sysib.sysib_322.ext_names[0], sizeof(sysib.sysib_322.ext_names[0]), qemu_name, '\0'); > } else { > ebcdic_put(sysib.sysib_322.vm[0].name, "TCGguest", 8); > strcpy((char *)sysib.sysib_322.ext_names[0], "TCGguest"); >