Re: [PATCH linux-next] kunit: tool: use absolute path for wget

From: David Gow
Date: Thu Sep 22 2022 - 06:10:16 EST


On Thu, Sep 22, 2022 at 4:36 PM <cgel.zte@xxxxxxxxx> wrote:
>
> From: Xu Panda <xu.panda@xxxxxxxxxx>
>
> Not using absolute path when invoking wget can lead to serious
> security issues.
>
> Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
> Signed-off-by: Xu Panda <xu.panda@xxxxxxxxxx>
> ---

This seems mostly okay to me -- we'd be abandoning people who have
wget in an unusual location, but I don't think there are many people
who want to run KUnit under RISC-V, have wget in a non-standard
location, and can't acquire the bios file themselves.

So this is:
Reviewed-by: David Gow <davidgow@xxxxxxxxxx>

However, would a patch like this make _more_ sense? It looks like (at
least on Debian and Arch), the OpenSBI bios is installed as part of
the appropriate qemu package anyway, into a standard location.
---
diff --git a/tools/testing/kunit/qemu_configs/riscv.py
b/tools/testing/kunit/qemu_configs/riscv.py
index 6207be146d26..12a1d525978a 100644
--- a/tools/testing/kunit/qemu_configs/riscv.py
+++ b/tools/testing/kunit/qemu_configs/riscv.py
@@ -3,17 +3,13 @@ import os
import os.path
import sys

-GITHUB_OPENSBI_URL =
'https://github.com/qemu/qemu/raw/master/pc-bios/opensbi-riscv64-generic-fw_dynamic.bin'
-OPENSBI_FILE = os.path.basename(GITHUB_OPENSBI_URL)
+OPENSBI_FILE = 'opensbi-riscv64-generic-fw_dynamic.bin'
+OPENSBI_PATH = '/usr/share/qemu/' + OPENSBI_FILE

-if not os.path.isfile(OPENSBI_FILE):
- print('\n\nOpenSBI file is not in the current working directory.\n'
- 'Would you like me to download it for you from:\n' +
GITHUB_OPENSBI_URL + ' ?\n')
- response = input('yes/[no]: ')
- if response.strip() == 'yes':
- os.system('wget ' + GITHUB_OPENSBI_URL)
- else:
- sys.exit()
+if not os.path.isfile(OPENSBI_PATH):
+ print('\n\nOpenSBI bios was not found in "' + OPENSBI_PATH + '".\n'
+ 'Please ensure that qemu-system-riscv is installed, or
edit the path in "qemu_configs/riscv.py"\n')
+ sys.exit()

QEMU_ARCH = QemuArchParams(linux_arch='riscv',
kconfig='''
@@ -29,4 +25,4 @@ CONFIG_SERIAL_EARLYCON_RISCV_SBI=y''',
extra_qemu_params=[
'-machine', 'virt',
'-cpu', 'rv64',
- '-bios',
'opensbi-riscv64-generic-fw_dynamic.bin'])
+ '-bios', OPENSBI_PATH])
---

That way, we could avoid using wget at all. (I did confirm that this
is the only use of it anywhere in kunit_tool.)

The other options would be to use some python library to download it?

Thoughts?
-- David

> tools/testing/kunit/qemu_configs/riscv.py | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/kunit/qemu_configs/riscv.py b/tools/testing/kunit/qemu_configs/riscv.py
> index 6207be146d26..c3dcd654ca15 100644
> --- a/tools/testing/kunit/qemu_configs/riscv.py
> +++ b/tools/testing/kunit/qemu_configs/riscv.py
> @@ -11,7 +11,7 @@ if not os.path.isfile(OPENSBI_FILE):
> 'Would you like me to download it for you from:\n' + GITHUB_OPENSBI_URL + ' ?\n')
> response = input('yes/[no]: ')
> if response.strip() == 'yes':
> - os.system('wget ' + GITHUB_OPENSBI_URL)
> + os.system('/usr/bin/wget ' + GITHUB_OPENSBI_URL)
> else:
> sys.exit()
>
> --
> 2.15.2
>
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