* [PATCH] x86/hyperv: Fix error pointer dereference
@ 2026-02-18 19:09 Ethan Tidmore
2026-02-18 19:11 ` Ethan Tidmore
0 siblings, 1 reply; 3+ messages in thread
From: Ethan Tidmore @ 2026-02-18 19:09 UTC (permalink / raw)
To: K . Y . Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li,
Saurabh Sengar
Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
H . Peter Anvin, Michael Kelley, x86, linux-hyperv, linux-kernel,
Ethan Tidmore
The function idle_thread_get() can return an error pointer and is not
checked for it. Add check for error pointer.
Detected by Smatch:
arch/x86/hyperv/hv_vtl.c:126 hv_vtl_bringup_vcpu() error:
'idle' dereferencing possible ERR_PTR()
Fixes: 2b4b90e053a29 ("x86/hyperv: Use per cpu initial stack for vtl context")
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
---
v2:
- Fixed typo.
arch/x86/hyperv/hv_vtl.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/hyperv/hv_vtl.c b/arch/x86/hyperv/hv_vtl.c
index c0edaed0efb3..9b6a9bc4ab76 100644
--- a/arch/x86/hyperv/hv_vtl.c
+++ b/arch/x86/hyperv/hv_vtl.c
@@ -110,7 +110,7 @@ static void hv_vtl_ap_entry(void)
static int hv_vtl_bringup_vcpu(u32 target_vp_index, int cpu, u64 eip_ignored)
{
- u64 status;
+ u64 status, rsp, rip;
int ret = 0;
struct hv_enable_vp_vtl *input;
unsigned long irq_flags;
@@ -123,9 +123,11 @@ static int hv_vtl_bringup_vcpu(u32 target_vp_index, int cpu, u64 eip_ignored)
struct desc_struct *gdt;
struct task_struct *idle = idle_thread_get(cpu);
- u64 rsp = (unsigned long)idle->thread.sp;
+ if (IS_ERR(idle))
+ return PTR_ERR(idle);
- u64 rip = (u64)&hv_vtl_ap_entry;
+ rsp = (unsigned long)idle->thread.sp;
+ rip = (u64)&hv_vtl_ap_entry;
native_store_gdt(&gdt_ptr);
store_idt(&idt_ptr);
--
2.53.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/hyperv: Fix error pointer dereference
2026-02-18 19:09 [PATCH] x86/hyperv: Fix error pointer dereference Ethan Tidmore
@ 2026-02-18 19:11 ` Ethan Tidmore
2026-02-18 23:22 ` Wei Liu
0 siblings, 1 reply; 3+ messages in thread
From: Ethan Tidmore @ 2026-02-18 19:11 UTC (permalink / raw)
To: Ethan Tidmore, K . Y . Srinivasan, Haiyang Zhang, Wei Liu,
Dexuan Cui, Long Li, Saurabh Sengar
Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen,
H . Peter Anvin, Michael Kelley, x86, linux-hyperv, linux-kernel
On Wed Feb 18, 2026 at 1:09 PM CST, Ethan Tidmore wrote:
> The function idle_thread_get() can return an error pointer and is not
> checked for it. Add check for error pointer.
>
> Detected by Smatch:
> arch/x86/hyperv/hv_vtl.c:126 hv_vtl_bringup_vcpu() error:
> 'idle' dereferencing possible ERR_PTR()
>
> Fixes: 2b4b90e053a29 ("x86/hyperv: Use per cpu initial stack for vtl context")
> Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
> ---
Oops, forgot v2 header this is the v2.
Thanks,
ET
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86/hyperv: Fix error pointer dereference
2026-02-18 19:11 ` Ethan Tidmore
@ 2026-02-18 23:22 ` Wei Liu
0 siblings, 0 replies; 3+ messages in thread
From: Wei Liu @ 2026-02-18 23:22 UTC (permalink / raw)
To: Ethan Tidmore
Cc: K . Y . Srinivasan, Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li,
Saurabh Sengar, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, H . Peter Anvin, Michael Kelley, x86, linux-hyperv,
linux-kernel
On Wed, Feb 18, 2026 at 01:11:18PM -0600, Ethan Tidmore wrote:
> On Wed Feb 18, 2026 at 1:09 PM CST, Ethan Tidmore wrote:
> > The function idle_thread_get() can return an error pointer and is not
> > checked for it. Add check for error pointer.
> >
> > Detected by Smatch:
> > arch/x86/hyperv/hv_vtl.c:126 hv_vtl_bringup_vcpu() error:
> > 'idle' dereferencing possible ERR_PTR()
> >
> > Fixes: 2b4b90e053a29 ("x86/hyperv: Use per cpu initial stack for vtl context")
> > Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
> > ---
>
> Oops, forgot v2 header this is the v2.
Applied. Thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-02-18 19:11 ` Ethan Tidmore
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