diff mbox series

soc: fsl: qe: Replace all non-returning strlcpy with strscpy

Message ID 20230523021425.2406309-1-azeemshaikh38@gmail.com (mailing list archive)
State Handled Elsewhere
Headers show
Series soc: fsl: qe: Replace all non-returning strlcpy with strscpy | expand

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Commit Message

Azeem Shaikh May 23, 2023, 2:14 a.m. UTC
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
 drivers/soc/fsl/qe/qe.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Kees Cook May 23, 2023, 5:20 p.m. UTC | #1
On Tue, May 23, 2023 at 02:14:25AM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>

Reviewed-by: Kees Cook <keescook@chromium.org>
Azeem Shaikh July 10, 2023, 2:35 a.m. UTC | #2
On Tue, May 23, 2023 at 1:20 PM Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, May 23, 2023 at 02:14:25AM +0000, Azeem Shaikh wrote:
> > strlcpy() reads the entire source buffer first.
> > This read may exceed the destination size limit.
> > This is both inefficient and can lead to linear read
> > overflows if a source string is not NUL-terminated [1].
> > In an effort to remove strlcpy() completely [2], replace
> > strlcpy() here with strscpy().
> > No return values were used, so direct replacement is safe.
> >
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> > [2] https://github.com/KSPP/linux/issues/89
> >
> > Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>

Friendly ping on this.
Leo Li July 10, 2023, 4:46 p.m. UTC | #3
> -----Original Message-----
> From: Azeem Shaikh <azeemshaikh38@gmail.com>
> Sent: Sunday, July 9, 2023 9:36 PM
> To: Kees Cook <keescook@chromium.org>
> Cc: Qiang Zhao <qiang.zhao@nxp.com>; linux-hardening@vger.kernel.org;
> linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org; Leo Li
> <leoyang.li@nxp.com>; linux-arm-kernel@lists.infradead.org
> Subject: Re: [PATCH] soc: fsl: qe: Replace all non-returning strlcpy with
> strscpy
> 
> On Tue, May 23, 2023 at 1:20 PM Kees Cook <keescook@chromium.org>
> wrote:
> >
> > On Tue, May 23, 2023 at 02:14:25AM +0000, Azeem Shaikh wrote:
> > > strlcpy() reads the entire source buffer first.
> > > This read may exceed the destination size limit.
> > > This is both inefficient and can lead to linear read overflows if a
> > > source string is not NUL-terminated [1].
> > > In an effort to remove strlcpy() completely [2], replace
> > > strlcpy() here with strscpy().
> > > No return values were used, so direct replacement is safe.
> > >
> > > [1]
> > >
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fww
> > >
> w.kernel.org%2Fdoc%2Fhtml%2Flatest%2Fprocess%2Fdeprecated.html%23s
> tr
> > >
> lcpy&data=05%7C01%7Cleoyang.li%40nxp.com%7C11f9df1df1b5440e4ec108
> db8
> > >
> 0ee64de%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63824553360
> 3780
> > >
> 889%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2lu
> MzIiLCJB
> > >
> TiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=jcTy3IF37wqC1
> MWsSuF
> > > %2F51Z1trQEMaow7BHkPSh3hzI%3D&reserved=0
> > > [2]
> > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgi
> > >
> thub.com%2FKSPP%2Flinux%2Fissues%2F89&data=05%7C01%7Cleoyang.li%
> 40nx
> > >
> p.com%7C11f9df1df1b5440e4ec108db80ee64de%7C686ea1d3bc2b4c6fa92cd
> 99c5
> > >
> c301635%7C0%7C0%7C638245533603780889%7CUnknown%7CTWFpbGZsb3d
> 8eyJWIjo
> > >
> iMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C30
> 00%7
> > >
> C%7C%7C&sdata=Blr0W1oYPIw5uDu7HqlEkU7xOuAo4bQNkk%2Bt%2BAuFqc
> s%3D&res
> > > erved=0
> > >
> > > Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> >
> > Reviewed-by: Kees Cook <keescook@chromium.org>
> >
> 
> Friendly ping on this.

Sorry for the late response.  But I found some old discussions with the conclusion to be not converting old users.  Has this been changed later on?
https://lwn.net/Articles/659214/

Regards,
Leo
Azeem Shaikh July 11, 2023, 11:55 p.m. UTC | #4
> Sorry for the late response.  But I found some old discussions with the conclusion to be not converting old users.  Has this been changed later on?
> https://lwn.net/Articles/659214/
>

@Kees Cook what's your advice here?
Kees Cook July 13, 2023, 12:06 a.m. UTC | #5
On Mon, Jul 10, 2023 at 04:46:50PM +0000, Leo Li wrote:
> 
> 
> > -----Original Message-----
> > From: Azeem Shaikh <azeemshaikh38@gmail.com>
> > Sent: Sunday, July 9, 2023 9:36 PM
> > To: Kees Cook <keescook@chromium.org>
> > Cc: Qiang Zhao <qiang.zhao@nxp.com>; linux-hardening@vger.kernel.org;
> > linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org; Leo Li
> > <leoyang.li@nxp.com>; linux-arm-kernel@lists.infradead.org
> > Subject: Re: [PATCH] soc: fsl: qe: Replace all non-returning strlcpy with
> > strscpy
> > 
> > On Tue, May 23, 2023 at 1:20 PM Kees Cook <keescook@chromium.org>
> > wrote:
> > >
> > > On Tue, May 23, 2023 at 02:14:25AM +0000, Azeem Shaikh wrote:
> > > > strlcpy() reads the entire source buffer first.
> > > > This read may exceed the destination size limit.
> > > > This is both inefficient and can lead to linear read overflows if a
> > > > source string is not NUL-terminated [1].
> > > > In an effort to remove strlcpy() completely [2], replace
> > > > strlcpy() here with strscpy().
> > > > No return values were used, so direct replacement is safe.
> > > >
> > > > [1]
> > > >
> > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fww
> > > >
> > w.kernel.org%2Fdoc%2Fhtml%2Flatest%2Fprocess%2Fdeprecated.html%23s
> > tr
> > > >
> > lcpy&data=05%7C01%7Cleoyang.li%40nxp.com%7C11f9df1df1b5440e4ec108
> > db8
> > > >
> > 0ee64de%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C63824553360
> > 3780
> > > >
> > 889%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2lu
> > MzIiLCJB
> > > >
> > TiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=jcTy3IF37wqC1
> > MWsSuF
> > > > %2F51Z1trQEMaow7BHkPSh3hzI%3D&reserved=0
> > > > [2]
> > > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgi
> > > >
> > thub.com%2FKSPP%2Flinux%2Fissues%2F89&data=05%7C01%7Cleoyang.li%
> > 40nx
> > > >
> > p.com%7C11f9df1df1b5440e4ec108db80ee64de%7C686ea1d3bc2b4c6fa92cd
> > 99c5
> > > >
> > c301635%7C0%7C0%7C638245533603780889%7CUnknown%7CTWFpbGZsb3d
> > 8eyJWIjo
> > > >
> > iMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C30
> > 00%7
> > > >
> > C%7C%7C&sdata=Blr0W1oYPIw5uDu7HqlEkU7xOuAo4bQNkk%2Bt%2BAuFqc
> > s%3D&res
> > > > erved=0
> > > >
> > > > Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
> > >
> > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > >
> > 
> > Friendly ping on this.
> 
> Sorry for the late response.  But I found some old discussions with the conclusion to be not converting old users.  Has this been changed later on?
> https://lwn.net/Articles/659214/

The objection was with _mass_ conversions due to the risk of regressions
being introduced in a way that makes it hard to revert/bisect, etc.
We've being long on the road to doing these conversions to eliminate
strlcpy(), which continues to get introduced into the kernel, even
though it is risky.
Kees Cook July 26, 2023, 9:53 p.m. UTC | #6
On Tue, 23 May 2023 02:14:25 +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [...]

Applied, thanks!

[1/1] soc: fsl: qe: Replace all non-returning strlcpy with strscpy
      (no commit info)

Best regards,
diff mbox series

Patch

diff --git a/drivers/soc/fsl/qe/qe.c b/drivers/soc/fsl/qe/qe.c
index b3c226eb5292..58746e570d14 100644
--- a/drivers/soc/fsl/qe/qe.c
+++ b/drivers/soc/fsl/qe/qe.c
@@ -524,7 +524,7 @@  int qe_upload_firmware(const struct qe_firmware *firmware)
 	 * saved microcode information and put in the new.
 	 */
 	memset(&qe_firmware_info, 0, sizeof(qe_firmware_info));
-	strlcpy(qe_firmware_info.id, firmware->id, sizeof(qe_firmware_info.id));
+	strscpy(qe_firmware_info.id, firmware->id, sizeof(qe_firmware_info.id));
 	qe_firmware_info.extended_modes = be64_to_cpu(firmware->extended_modes);
 	memcpy(qe_firmware_info.vtraps, firmware->vtraps,
 		sizeof(firmware->vtraps));
@@ -599,7 +599,7 @@  struct qe_firmware_info *qe_get_firmware_info(void)
 	/* Copy the data into qe_firmware_info*/
 	sprop = of_get_property(fw, "id", NULL);
 	if (sprop)
-		strlcpy(qe_firmware_info.id, sprop,
+		strscpy(qe_firmware_info.id, sprop,
 			sizeof(qe_firmware_info.id));
 
 	of_property_read_u64(fw, "extended-modes",