[Xen-devel] [PATCH] x86/irq: Fix undefined behaviour in irq_move_cleanup_interrupt()

Andrew Cooper posted 1 patch 2 weeks ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/xen tags/patchew/1559831189-26103-1-git-send-email-andrew.cooper3@citrix.com
xen/arch/x86/irq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

[Xen-devel] [PATCH] x86/irq: Fix undefined behaviour in irq_move_cleanup_interrupt()

Posted by Andrew Cooper 2 weeks ago
UBSAN reports:

  (XEN) ================================================================================
  (XEN) UBSAN: Undefined behaviour in irq.c:682:22
  (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
  (XEN) ----[ Xen-4.13-unstable  x86_64  debug=y   Not tainted ]----
  (XEN) CPU:    16
  (XEN) RIP:    e008:[<ffff82d0802a54ce>] ubsan.c#ubsan_epilogue+0xa/0xc2
  <snip>
  (XEN) Xen call trace:
  (XEN)    [<ffff82d0802a54ce>] ubsan.c#ubsan_epilogue+0xa/0xc2
  (XEN)    [<ffff82d0802a6009>] __ubsan_handle_shift_out_of_bounds+0x15d/0x16c
  (XEN)    [<ffff82d08031ae77>] irq_move_cleanup_interrupt+0x25c/0x4a0
  (XEN)    [<ffff82d08031b585>] do_IRQ+0x19d/0x104c
  (XEN)    [<ffff82d08050c8ba>] common_interrupt+0x10a/0x120
  (XEN)    [<ffff82d0803b13a6>] cpu_idle.c#acpi_idle_do_entry+0x1de/0x24b
  (XEN)    [<ffff82d0803b1d83>] cpu_idle.c#acpi_processor_idle+0x5c8/0x94e
  (XEN)    [<ffff82d0802fa8d6>] domain.c#idle_loop+0xee/0x101
  (XEN)
  (XEN) ================================================================================

Switch to an unsigned shift, and correct the surrounding style.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
---
 xen/arch/x86/irq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index d6451a9..6847fb4 100644
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -679,7 +679,8 @@ void irq_move_cleanup_interrupt(struct cpu_user_regs *regs)
          * next attempt by sending another IRQ_MOVE_CLEANUP_VECTOR
          * to myself.
          */
-        if (irr  & (1 << (vector % 32))) {
+        if ( irr & (1u << (vector % 32)) )
+        {
             send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
             TRACE_3D(TRC_HW_IRQ_MOVE_CLEANUP_DELAY,
                      irq, vector, smp_processor_id());
-- 
2.1.4


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Re: [Xen-devel] [PATCH] x86/irq: Fix undefined behaviour in irq_move_cleanup_interrupt()

Posted by Roger Pau Monné 2 weeks ago
On Thu, Jun 06, 2019 at 03:26:29PM +0100, Andrew Cooper wrote:
> UBSAN reports:
> 
>   (XEN) ================================================================================
>   (XEN) UBSAN: Undefined behaviour in irq.c:682:22
>   (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
>   (XEN) ----[ Xen-4.13-unstable  x86_64  debug=y   Not tainted ]----
>   (XEN) CPU:    16
>   (XEN) RIP:    e008:[<ffff82d0802a54ce>] ubsan.c#ubsan_epilogue+0xa/0xc2
>   <snip>
>   (XEN) Xen call trace:
>   (XEN)    [<ffff82d0802a54ce>] ubsan.c#ubsan_epilogue+0xa/0xc2
>   (XEN)    [<ffff82d0802a6009>] __ubsan_handle_shift_out_of_bounds+0x15d/0x16c
>   (XEN)    [<ffff82d08031ae77>] irq_move_cleanup_interrupt+0x25c/0x4a0
>   (XEN)    [<ffff82d08031b585>] do_IRQ+0x19d/0x104c
>   (XEN)    [<ffff82d08050c8ba>] common_interrupt+0x10a/0x120
>   (XEN)    [<ffff82d0803b13a6>] cpu_idle.c#acpi_idle_do_entry+0x1de/0x24b
>   (XEN)    [<ffff82d0803b1d83>] cpu_idle.c#acpi_processor_idle+0x5c8/0x94e
>   (XEN)    [<ffff82d0802fa8d6>] domain.c#idle_loop+0xee/0x101
>   (XEN)
>   (XEN) ================================================================================
> 
> Switch to an unsigned shift, and correct the surrounding style.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks.

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Re: [Xen-devel] [PATCH] x86/irq: Fix undefined behaviour in irq_move_cleanup_interrupt()

Posted by Jan Beulich 2 weeks ago
>>> On 06.06.19 at 16:31, <roger.pau@citrix.com> wrote:
> On Thu, Jun 06, 2019 at 03:26:29PM +0100, Andrew Cooper wrote:
>> UBSAN reports:
>> 
>>   (XEN) 
> =============================================================================
> ===
>>   (XEN) UBSAN: Undefined behaviour in irq.c:682:22
>>   (XEN) left shift of 1 by 31 places cannot be represented in type 'int'
>>   (XEN) ----[ Xen-4.13-unstable  x86_64  debug=y   Not tainted ]----
>>   (XEN) CPU:    16
>>   (XEN) RIP:    e008:[<ffff82d0802a54ce>] ubsan.c#ubsan_epilogue+0xa/0xc2
>>   <snip>
>>   (XEN) Xen call trace:
>>   (XEN)    [<ffff82d0802a54ce>] ubsan.c#ubsan_epilogue+0xa/0xc2
>>   (XEN)    [<ffff82d0802a6009>] __ubsan_handle_shift_out_of_bounds+0x15d/0x16c
>>   (XEN)    [<ffff82d08031ae77>] irq_move_cleanup_interrupt+0x25c/0x4a0
>>   (XEN)    [<ffff82d08031b585>] do_IRQ+0x19d/0x104c
>>   (XEN)    [<ffff82d08050c8ba>] common_interrupt+0x10a/0x120
>>   (XEN)    [<ffff82d0803b13a6>] cpu_idle.c#acpi_idle_do_entry+0x1de/0x24b
>>   (XEN)    [<ffff82d0803b1d83>] cpu_idle.c#acpi_processor_idle+0x5c8/0x94e
>>   (XEN)    [<ffff82d0802fa8d6>] domain.c#idle_loop+0xee/0x101
>>   (XEN)
>>   (XEN) 
> =============================================================================
> ===
>> 
>> Switch to an unsigned shift, and correct the surrounding style.
>> 
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> 
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Acked-by: Jan Beulich <jbeulich@suse.com>


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