* [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table
@ 2017-10-13 13:17 Christoffer Dall
2017-10-13 13:38 ` Marc Zyngier
2017-10-13 14:00 ` Andrew Jones
0 siblings, 2 replies; 4+ messages in thread
From: Christoffer Dall @ 2017-10-13 13:17 UTC (permalink / raw)
To: linux-arm-kernel
We currently allocate an entry dynamically, but we never check if the
allocation actually succeeded. We actually don't need a dynamic
allocation, because we know the maximum size of an ITS table entry, so
we can simply use an allocation on the stack.
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
virt/kvm/arm/vgic/vgic-its.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index f51c1e1..1d2668b 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1801,37 +1801,33 @@ typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry,
static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
int start_id, entry_fn_t fn, void *opaque)
{
- void *entry = kzalloc(esz, GFP_KERNEL);
struct kvm *kvm = its->dev->kvm;
unsigned long len = size;
int id = start_id;
gpa_t gpa = base;
+ char entry[esz]
int ret;
+ memset(entry, 0, esz);
+
while (len > 0) {
int next_offset;
size_t byte_offset;
ret = kvm_read_guest(kvm, gpa, entry, esz);
if (ret)
- goto out;
+ return ret;
next_offset = fn(its, id, entry, opaque);
- if (next_offset <= 0) {
- ret = next_offset;
- goto out;
- }
+ if (next_offset <= 0)
+ return next_offset;
byte_offset = next_offset * esz;
id += next_offset;
gpa += byte_offset;
len -= byte_offset;
}
- ret = 1;
-
-out:
- kfree(entry);
- return ret;
+ return 1;
}
/**
--
2.9.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table
2017-10-13 13:17 [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table Christoffer Dall
@ 2017-10-13 13:38 ` Marc Zyngier
2017-10-13 14:00 ` Andrew Jones
1 sibling, 0 replies; 4+ messages in thread
From: Marc Zyngier @ 2017-10-13 13:38 UTC (permalink / raw)
To: linux-arm-kernel
On 13/10/17 14:17, Christoffer Dall wrote:
> We currently allocate an entry dynamically, but we never check if the
> allocation actually succeeded. We actually don't need a dynamic
> allocation, because we know the maximum size of an ITS table entry, so
> we can simply use an allocation on the stack.
>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
> ---
> virt/kvm/arm/vgic/vgic-its.c | 18 +++++++-----------
> 1 file changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index f51c1e1..1d2668b 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1801,37 +1801,33 @@ typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry,
> static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
> int start_id, entry_fn_t fn, void *opaque)
> {
> - void *entry = kzalloc(esz, GFP_KERNEL);
> struct kvm *kvm = its->dev->kvm;
> unsigned long len = size;
> int id = start_id;
> gpa_t gpa = base;
> + char entry[esz]
> int ret;
>
> + memset(entry, 0, esz);
> +
> while (len > 0) {
> int next_offset;
> size_t byte_offset;
>
> ret = kvm_read_guest(kvm, gpa, entry, esz);
> if (ret)
> - goto out;
> + return ret;
>
> next_offset = fn(its, id, entry, opaque);
> - if (next_offset <= 0) {
> - ret = next_offset;
> - goto out;
> - }
> + if (next_offset <= 0)
> + return next_offset;
>
> byte_offset = next_offset * esz;
> id += next_offset;
> gpa += byte_offset;
> len -= byte_offset;
> }
> - ret = 1;
> -
> -out:
> - kfree(entry);
> - return ret;
> + return 1;
> }
>
> /**
>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table
2017-10-13 13:17 [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table Christoffer Dall
2017-10-13 13:38 ` Marc Zyngier
@ 2017-10-13 14:00 ` Andrew Jones
2017-10-13 17:49 ` Christoffer Dall
1 sibling, 1 reply; 4+ messages in thread
From: Andrew Jones @ 2017-10-13 14:00 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Oct 13, 2017 at 03:17:34PM +0200, Christoffer Dall wrote:
> We currently allocate an entry dynamically, but we never check if the
> allocation actually succeeded. We actually don't need a dynamic
> allocation, because we know the maximum size of an ITS table entry, so
> we can simply use an allocation on the stack.
>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
> ---
> virt/kvm/arm/vgic/vgic-its.c | 18 +++++++-----------
> 1 file changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index f51c1e1..1d2668b 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -1801,37 +1801,33 @@ typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry,
> static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
> int start_id, entry_fn_t fn, void *opaque)
> {
> - void *entry = kzalloc(esz, GFP_KERNEL);
> struct kvm *kvm = its->dev->kvm;
> unsigned long len = size;
> int id = start_id;
> gpa_t gpa = base;
> + char entry[esz]
Might want a semicolon here :-)
drew
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table
2017-10-13 14:00 ` Andrew Jones
@ 2017-10-13 17:49 ` Christoffer Dall
0 siblings, 0 replies; 4+ messages in thread
From: Christoffer Dall @ 2017-10-13 17:49 UTC (permalink / raw)
To: linux-arm-kernel
On Fri, Oct 13, 2017 at 04:00:18PM +0200, Andrew Jones wrote:
> On Fri, Oct 13, 2017 at 03:17:34PM +0200, Christoffer Dall wrote:
> > We currently allocate an entry dynamically, but we never check if the
> > allocation actually succeeded. We actually don't need a dynamic
> > allocation, because we know the maximum size of an ITS table entry, so
> > we can simply use an allocation on the stack.
> >
> > Cc: <stable@vger.kernel.org>
> > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
> > ---
> > virt/kvm/arm/vgic/vgic-its.c | 18 +++++++-----------
> > 1 file changed, 7 insertions(+), 11 deletions(-)
> >
> > diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> > index f51c1e1..1d2668b 100644
> > --- a/virt/kvm/arm/vgic/vgic-its.c
> > +++ b/virt/kvm/arm/vgic/vgic-its.c
> > @@ -1801,37 +1801,33 @@ typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry,
> > static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
> > int start_id, entry_fn_t fn, void *opaque)
> > {
> > - void *entry = kzalloc(esz, GFP_KERNEL);
> > struct kvm *kvm = its->dev->kvm;
> > unsigned long len = size;
> > int id = start_id;
> > gpa_t gpa = base;
> > + char entry[esz]
>
> Might want a semicolon here :-)
>
Duh, yeah, left out the '-a' in my 'git commit --amend'...
Thanks!
-Christoffer
^ permalink raw reply [flat|nested] 4+ messages in thread
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2017-10-13 13:17 [PATCH v2] KVM: arm64: its: Fix missing dynamic allocation check in scan_its_table Christoffer Dall
2017-10-13 13:38 ` Marc Zyngier
2017-10-13 14:00 ` Andrew Jones
2017-10-13 17:49 ` Christoffer Dall
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