| Message ID | 20240507025010.1968881-2-mii@sfc.wide.ad.jp (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,1/1] accel/kvm: Fix segmentation fault | expand |
on 5/7/2024 10:50 AM, Masato Imai wrote: > When the KVM acceleration parameter is not set, executing calc_dirty_rate > with the -r or -b option results in a segmentation fault due to accessing > a null kvm_state pointer in the kvm_dirty_ring_enabled function. This > commit adds a null check for kvm_status to prevent segmentation faults. > > Signed-off-by: Masato Imai <mii@sfc.wide.ad.jp> LGTM, Tested-by: Li Zhijian <lizhijian@fujitsu.com> > --- > accel/kvm/kvm-all.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index c0be9f5eed..544293be8a 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -2329,7 +2329,7 @@ bool kvm_vcpu_id_is_valid(int vcpu_id) > > bool kvm_dirty_ring_enabled(void) > { > - return kvm_state->kvm_dirty_ring_size ? true : false; > + return kvm_state && kvm_state->kvm_dirty_ring_size; > } > > static void query_stats_cb(StatsResultList **result, StatsTarget target,
Hi Masato, On 7/5/24 04:50, Masato Imai wrote: > When the KVM acceleration parameter is not set, executing calc_dirty_rate > with the -r or -b option results in a segmentation fault due to accessing > a null kvm_state pointer in the kvm_dirty_ring_enabled function. This > commit adds a null check for kvm_status to prevent segmentation faults. > > Signed-off-by: Masato Imai <mii@sfc.wide.ad.jp> > --- > accel/kvm/kvm-all.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index c0be9f5eed..544293be8a 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -2329,7 +2329,7 @@ bool kvm_vcpu_id_is_valid(int vcpu_id) > > bool kvm_dirty_ring_enabled(void) > { > - return kvm_state->kvm_dirty_ring_size ? true : false; > + return kvm_state && kvm_state->kvm_dirty_ring_size; I missed the previous iterations of this patch. I disagree with this approach, we shouldn't call kvm_dirty_ring_enabled() if kvm_state is NULL, this is a bad API usage. So I'd rather assert(kvm_state) here and force the callers to check for kvm_enabled() before calling. > } > > static void query_stats_cb(StatsResultList **result, StatsTarget target,
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index c0be9f5eed..544293be8a 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -2329,7 +2329,7 @@ bool kvm_vcpu_id_is_valid(int vcpu_id) bool kvm_dirty_ring_enabled(void) { - return kvm_state->kvm_dirty_ring_size ? true : false; + return kvm_state && kvm_state->kvm_dirty_ring_size; } static void query_stats_cb(StatsResultList **result, StatsTarget target,
When the KVM acceleration parameter is not set, executing calc_dirty_rate with the -r or -b option results in a segmentation fault due to accessing a null kvm_state pointer in the kvm_dirty_ring_enabled function. This commit adds a null check for kvm_status to prevent segmentation faults. Signed-off-by: Masato Imai <mii@sfc.wide.ad.jp> --- accel/kvm/kvm-all.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)