Re: [PATCH v2 1/2] powerpc: Free fdt on error in elf64_load()

[Rob Herring]

On Wed, 21 Apr 2021 09:36:09 -0700, Lakshmi Ramasubramanian wrote:
> There are a few "goto out;" statements before the local variable "fdt"
> is initialized through the call to of_kexec_alloc_and_setup_fdt() in
> elf64_load().  This will result in an uninitialized "fdt" being passed
> to kvfree() in this function if there is an error before the call to
> of_kexec_alloc_and_setup_fdt().
> 
> If there is any error after fdt is allocated, but before it is
> saved in the arch specific kimage struct, free the fdt.
> 
> Reported-by: kernel test robot 
> Reported-by: Dan Carpenter 
> Signed-off-by: Michael Ellerman 
> Signed-off-by: Lakshmi Ramasubramanian 
> ---
>  arch/powerpc/kexec/elf_64.c | 16 ++--
>  1 file changed, 6 insertions(+), 10 deletions(-)
> 

Applied, thanks!

Re: [PATCH v2 1/2] powerpc: Free fdt on error in elf64_load()

[Lakshmi Ramasubramanian]

On 4/21/21 9:36 AM, Lakshmi Ramasubramanian wrote:

Hi Dan,


There are a few "goto out;" statements before the local variable "fdt"
is initialized through the call to of_kexec_alloc_and_setup_fdt() in
elf64_load().  This will result in an uninitialized "fdt" being passed
to kvfree() in this function if there is an error before the call to
of_kexec_alloc_and_setup_fdt().

If there is any error after fdt is allocated, but before it is
saved in the arch specific kimage struct, free the fdt.

Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Signed-off-by: Michael Ellerman 
Signed-off-by: Lakshmi Ramasubramanian 
---
  arch/powerpc/kexec/elf_64.c | 16 ++--
  1 file changed, 6 insertions(+), 10 deletions(-)



Please review this patch and Patch 2/2.

thanks,
 -lakshmi


diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 5a569bb51349..02662e72c53d 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -114,7 +114,7 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
  initrd_len, cmdline);
if (ret)
-   goto out;
+   goto out_free_fdt;
  
  	fdt_pack(fdt);
  
@@ -125,7 +125,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf,

kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
ret = kexec_add_buffer();
if (ret)
-   goto out;
+   goto out_free_fdt;
  
  	/* FDT will be freed in arch_kimage_file_post_load_cleanup */

image->arch.fdt = fdt;
@@ -140,18 +140,14 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
if (ret)
pr_err("Error setting up the purgatory.\n");
  
+	goto out;

+
+out_free_fdt:
+   kvfree(fdt);
  out:
kfree(modified_cmdline);
kexec_free_elf_info(_info);
  
-	/*

-* Once FDT buffer has been successfully passed to kexec_add_buffer(),
-* the FDT buffer address is saved in image->arch.fdt. In that case,
-* the memory cannot be freed here in case of any other error.
-*/
-   if (ret && !image->arch.fdt)
-   kvfree(fdt);
-
return ret ? ERR_PTR(ret) : NULL;
  }
  

[PATCH v2 1/2] powerpc: Free fdt on error in elf64_load()

[Lakshmi Ramasubramanian]

There are a few "goto out;" statements before the local variable "fdt"
is initialized through the call to of_kexec_alloc_and_setup_fdt() in
elf64_load().  This will result in an uninitialized "fdt" being passed
to kvfree() in this function if there is an error before the call to
of_kexec_alloc_and_setup_fdt().

If there is any error after fdt is allocated, but before it is
saved in the arch specific kimage struct, free the fdt.

Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Signed-off-by: Michael Ellerman 
Signed-off-by: Lakshmi Ramasubramanian 
---
 arch/powerpc/kexec/elf_64.c | 16 ++--
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c
index 5a569bb51349..02662e72c53d 100644
--- a/arch/powerpc/kexec/elf_64.c
+++ b/arch/powerpc/kexec/elf_64.c
@@ -114,7 +114,7 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr,
  initrd_len, cmdline);
if (ret)
-   goto out;
+   goto out_free_fdt;
 
fdt_pack(fdt);
 
@@ -125,7 +125,7 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
ret = kexec_add_buffer();
if (ret)
-   goto out;
+   goto out_free_fdt;
 
/* FDT will be freed in arch_kimage_file_post_load_cleanup */
image->arch.fdt = fdt;
@@ -140,18 +140,14 @@ static void *elf64_load(struct kimage *image, char 
*kernel_buf,
if (ret)
pr_err("Error setting up the purgatory.\n");
 
+   goto out;
+
+out_free_fdt:
+   kvfree(fdt);
 out:
kfree(modified_cmdline);
kexec_free_elf_info(_info);
 
-   /*
-* Once FDT buffer has been successfully passed to kexec_add_buffer(),
-* the FDT buffer address is saved in image->arch.fdt. In that case,
-* the memory cannot be freed here in case of any other error.
-*/
-   if (ret && !image->arch.fdt)
-   kvfree(fdt);
-
return ret ? ERR_PTR(ret) : NULL;
 }
 
-- 
2.31.0