Hi Lakshmi,
Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx> writes:
> 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.
>
> Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> ---
> 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;
Shouldn't there be a goto out_free_fdt if fdt_open_into fails?
>
> 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(&kbuf);
> 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);
Can just use kfree here?
Thanks,
Santosh
> out:
> kfree(modified_cmdline);
> kexec_free_elf_info(&elf_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
