[PATCH -next 1/2] kho: fix missing early_memunmap() call in kho_populate()

[PATCH -next 1/2] kho: fix missing early_memunmap() call in kho_populate()

[ranxiaokai627]

From: Ran Xiaokai <ran.xiaokai@zte.com.cn>

kho_populate() returns without calling early_memunmap() on success
path, this will cause early ioremap virtual address space leak.

Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
---

b50634c5e84a ("kho: cleanup error handling in kho_populate()")
has not landed in upstream, so
Cc: <stable@vger.kernel.org> is unnecessary?

 kernel/liveupdate/kexec_handover.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index fb3a7b67676e..76b714db175d 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -1463,6 +1463,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 	struct kho_scratch *scratch = NULL;
 	phys_addr_t mem_map_phys;
 	void *fdt = NULL;
+	int populated = 0;
 	int err;
 
 	/* Validate the input FDT */
@@ -1529,16 +1530,17 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
 	kho_in.scratch_phys = scratch_phys;
 	kho_in.mem_map_phys = mem_map_phys;
 	kho_scratch_cnt = scratch_cnt;
-	pr_info("found kexec handover data.\n");
 
-	return;
+	populated = 1;
+	pr_info("found kexec handover data.\n");
 
 err_unmap_scratch:
 	early_memunmap(scratch, scratch_len);
 err_unmap_fdt:
 	early_memunmap(fdt, fdt_len);
 err_report:
-	pr_warn("disabling KHO revival\n");
+	if (!populated)
+		pr_warn("disabling KHO revival\n");
 }
 
 /* Helper functions for kexec_file_load */
-- 
2.25.1

Re: [PATCH -next 1/2] kho: fix missing early_memunmap() call in kho_populate()

[Pratyush Yadav]

Hi Ran,

Thanks for the fix.

On Fri, Feb 06 2026, ranxiaokai627@163.com wrote:

> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>
> kho_populate() returns without calling early_memunmap() on success
> path, this will cause early ioremap virtual address space leak.
>
> Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
> ---
>
> b50634c5e84a ("kho: cleanup error handling in kho_populate()")
> has not landed in upstream, so
> Cc: <stable@vger.kernel.org> is unnecessary?
>
>  kernel/liveupdate/kexec_handover.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
> index fb3a7b67676e..76b714db175d 100644
> --- a/kernel/liveupdate/kexec_handover.c
> +++ b/kernel/liveupdate/kexec_handover.c
> @@ -1463,6 +1463,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>  	struct kho_scratch *scratch = NULL;
>  	phys_addr_t mem_map_phys;
>  	void *fdt = NULL;
> +	int populated = 0;

Nit: Please use a bool and true/false. I think it reads much nicer.

>  	int err;
>  
>  	/* Validate the input FDT */
> @@ -1529,16 +1530,17 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>  	kho_in.scratch_phys = scratch_phys;
>  	kho_in.mem_map_phys = mem_map_phys;
>  	kho_scratch_cnt = scratch_cnt;
> -	pr_info("found kexec handover data.\n");
>  
> -	return;
> +	populated = 1;
> +	pr_info("found kexec handover data.\n");
>  
>  err_unmap_scratch:
>  	early_memunmap(scratch, scratch_len);
>  err_unmap_fdt:
>  	early_memunmap(fdt, fdt_len);
>  err_report:

Nit: now that this code can be reached by non-error paths, we should
re-name the labels. I think dropping the "err_" prefix should be enough.

With these fixed,

Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

> -	pr_warn("disabling KHO revival\n");
> +	if (!populated)
> +		pr_warn("disabling KHO revival\n");
>  }
>  
>  /* Helper functions for kexec_file_load */

-- 
Regards,
Pratyush Yadav

Re: [PATCH -next 1/2] kho: fix missing early_memunmap() call in kho_populate()

[ranxiaokai627]

>Hi Ran,
>
>Thanks for the fix.
>
>On Fri, Feb 06 2026, ranxiaokai627@163.com wrote:
>
>> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>>
>> kho_populate() returns without calling early_memunmap() on success
>> path, this will cause early ioremap virtual address space leak.
>>
>> Fixes: b50634c5e84a ("kho: cleanup error handling in kho_populate()")
>> Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>> ---
>>
>> b50634c5e84a ("kho: cleanup error handling in kho_populate()")
>> has not landed in upstream, so
>> Cc: <stable@vger.kernel.org> is unnecessary?
>>
>>  kernel/liveupdate/kexec_handover.c | 8 +++++---
>>  1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
>> index fb3a7b67676e..76b714db175d 100644
>> --- a/kernel/liveupdate/kexec_handover.c
>> +++ b/kernel/liveupdate/kexec_handover.c
>> @@ -1463,6 +1463,7 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>>  	struct kho_scratch *scratch = NULL;
>>  	phys_addr_t mem_map_phys;
>>  	void *fdt = NULL;
>> +	int populated = 0;
>
>Nit: Please use a bool and true/false. I think it reads much nicer.

yes.

>>  	int err;
>>  
>>  	/* Validate the input FDT */
>> @@ -1529,16 +1530,17 @@ void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
>>  	kho_in.scratch_phys = scratch_phys;
>>  	kho_in.mem_map_phys = mem_map_phys;
>>  	kho_scratch_cnt = scratch_cnt;
>> -	pr_info("found kexec handover data.\n");
>>  
>> -	return;
>> +	populated = 1;
>> +	pr_info("found kexec handover data.\n");
>>  
>>  err_unmap_scratch:
>>  	early_memunmap(scratch, scratch_len);
>>  err_unmap_fdt:
>>  	early_memunmap(fdt, fdt_len);
>>  err_report:
>
>Nit: now that this code can be reached by non-error paths, we should
>re-name the labels. I think dropping the "err_" prefix should be enough.

Thanks for your review.
Very helpful suggestion. I will send a v2.

>With these fixed,
>
>Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
>
>> -	pr_warn("disabling KHO revival\n");
>> +	if (!populated)
>> +		pr_warn("disabling KHO revival\n");
>>  }
>>  
>>  /* Helper functions for kexec_file_load */