* [PATCH] eeprom: at25: Restore missing allocation
@ 2022-01-07 23:24 Kees Cook
2022-01-08 11:36 ` Andy Shevchenko
0 siblings, 1 reply; 3+ messages in thread
From: Kees Cook @ 2022-01-07 23:24 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Kees Cook, Andy Shevchenko, Arnd Bergmann, Jiri Prchal,
Ralph Siemsen, Mark Brown, linux-kernel, linux-hardening
Building under CONFIG_FORTIFY_SOURCE=y and -Warray-bounds complained about
strncpy() being used against an empty object. It turns out this was due to
the at25 allocation going missing during a conflict resolution. Restore
this, and while we're here take the opportunity to do another strncpy()
replacement, since it's use is deprecated[1].
Seen as:
In function 'strncpy',
inlined from 'at25_fw_to_chip.constprop' at drivers/misc/eeprom/at25.c:312:2:
./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
48 | #define __underlying_strncpy __builtin_strncpy
| ^
./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
59 | return __underlying_strncpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~~
In function 'strncpy',
inlined from 'at25_fram_to_chip' at drivers/misc/eeprom/at25.c:373:2,
inlined from 'at25_probe' at drivers/misc/eeprom/at25.c:453:10:
./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
48 | #define __underlying_strncpy __builtin_strncpy
| ^
./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
59 | return __underlying_strncpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~~
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Fixes: af40d16042d6 ("Merge v5.15-rc5 into char-misc-next")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Prchal <jiri.prchal@aksignal.cz>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/misc/eeprom/at25.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index c3305bdda69c..1a19fa5728c8 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -309,7 +309,7 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
u32 val;
int err;
- strncpy(chip->name, "at25", sizeof(chip->name));
+ strscpy(chip->name, "at25", sizeof(chip->name));
err = device_property_read_u32(dev, "size", &val);
if (err)
@@ -370,7 +370,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip)
u8 id[FM25_ID_LEN];
int i;
- strncpy(chip->name, "fm25", sizeof(chip->name));
+ strscpy(chip->name, "fm25", sizeof(chip->name));
/* Get ID of chip */
fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN);
@@ -440,6 +440,10 @@ static int at25_probe(struct spi_device *spi)
return -ENXIO;
}
+ at25 = devm_kzalloc(&spi->dev, sizeof(struct at25_data), GFP_KERNEL);
+ if (!at25)
+ return -ENOMEM;
+
mutex_init(&at25->lock);
at25->spi = spi;
spi_set_drvdata(spi, at25);
--
2.30.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] eeprom: at25: Restore missing allocation
2022-01-07 23:24 [PATCH] eeprom: at25: Restore missing allocation Kees Cook
@ 2022-01-08 11:36 ` Andy Shevchenko
2022-01-12 20:41 ` Kees Cook
0 siblings, 1 reply; 3+ messages in thread
From: Andy Shevchenko @ 2022-01-08 11:36 UTC (permalink / raw)
To: Kees Cook
Cc: Greg Kroah-Hartman, Andy Shevchenko, Arnd Bergmann, Jiri Prchal,
Ralph Siemsen, Mark Brown, Linux Kernel Mailing List,
linux-hardening
On Sat, Jan 8, 2022 at 1:01 PM Kees Cook <keescook@chromium.org> wrote:
>
> Building under CONFIG_FORTIFY_SOURCE=y and -Warray-bounds complained about
> strncpy() being used against an empty object. It turns out this was due to
> the at25 allocation going missing during a conflict resolution. Restore
> this, and while we're here take the opportunity to do another strncpy()
> replacement, since it's use is deprecated[1].
>
> Seen as:
>
> In function 'strncpy',
> inlined from 'at25_fw_to_chip.constprop' at drivers/misc/eeprom/at25.c:312:2:
> ./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
> 48 | #define __underlying_strncpy __builtin_strncpy
> | ^
> ./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
> 59 | return __underlying_strncpy(p, q, size);
> | ^~~~~~~~~~~~~~~~~~~~
> In function 'strncpy',
> inlined from 'at25_fram_to_chip' at drivers/misc/eeprom/at25.c:373:2,
> inlined from 'at25_probe' at drivers/misc/eeprom/at25.c:453:10:
> ./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
> 48 | #define __underlying_strncpy __builtin_strncpy
> | ^
> ./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
> 59 | return __underlying_strncpy(p, q, size);
> | ^~~~~~~~~~~~~~~~~~~~
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Thanks!
With or without the below comment being addressed
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Fixes: af40d16042d6 ("Merge v5.15-rc5 into char-misc-next")
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Jiri Prchal <jiri.prchal@aksignal.cz>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> drivers/misc/eeprom/at25.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
> index c3305bdda69c..1a19fa5728c8 100644
> --- a/drivers/misc/eeprom/at25.c
> +++ b/drivers/misc/eeprom/at25.c
> @@ -309,7 +309,7 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
> u32 val;
> int err;
>
> - strncpy(chip->name, "at25", sizeof(chip->name));
> + strscpy(chip->name, "at25", sizeof(chip->name));
>
> err = device_property_read_u32(dev, "size", &val);
> if (err)
> @@ -370,7 +370,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip)
> u8 id[FM25_ID_LEN];
> int i;
>
> - strncpy(chip->name, "fm25", sizeof(chip->name));
> + strscpy(chip->name, "fm25", sizeof(chip->name));
>
> /* Get ID of chip */
> fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN);
> @@ -440,6 +440,10 @@ static int at25_probe(struct spi_device *spi)
> return -ENXIO;
> }
>
> + at25 = devm_kzalloc(&spi->dev, sizeof(struct at25_data), GFP_KERNEL);
I would use sizeof(*at25) but I think you restored the exact context.
> + if (!at25)
> + return -ENOMEM;
> +
> mutex_init(&at25->lock);
> at25->spi = spi;
> spi_set_drvdata(spi, at25);
> --
> 2.30.2
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] eeprom: at25: Restore missing allocation
2022-01-08 11:36 ` Andy Shevchenko
@ 2022-01-12 20:41 ` Kees Cook
0 siblings, 0 replies; 3+ messages in thread
From: Kees Cook @ 2022-01-12 20:41 UTC (permalink / raw)
To: Andy Shevchenko
Cc: Greg Kroah-Hartman, Andy Shevchenko, Arnd Bergmann, Jiri Prchal,
Ralph Siemsen, Mark Brown, Linux Kernel Mailing List,
linux-hardening
On Sat, Jan 08, 2022 at 01:36:12PM +0200, Andy Shevchenko wrote:
> On Sat, Jan 8, 2022 at 1:01 PM Kees Cook <keescook@chromium.org> wrote:
> >
> > Building under CONFIG_FORTIFY_SOURCE=y and -Warray-bounds complained about
> > strncpy() being used against an empty object. It turns out this was due to
> > the at25 allocation going missing during a conflict resolution. Restore
> > this, and while we're here take the opportunity to do another strncpy()
> > replacement, since it's use is deprecated[1].
> >
> > Seen as:
> >
> > In function 'strncpy',
> > inlined from 'at25_fw_to_chip.constprop' at drivers/misc/eeprom/at25.c:312:2:
> > ./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
> > 48 | #define __underlying_strncpy __builtin_strncpy
> > | ^
> > ./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
> > 59 | return __underlying_strncpy(p, q, size);
> > | ^~~~~~~~~~~~~~~~~~~~
> > In function 'strncpy',
> > inlined from 'at25_fram_to_chip' at drivers/misc/eeprom/at25.c:373:2,
> > inlined from 'at25_probe' at drivers/misc/eeprom/at25.c:453:10:
> > ./include/linux/fortify-string.h:48:33: warning: '__builtin_strncpy' offset [0, 9] is out of the bounds [0, 0] [-Warray-bounds]
> > 48 | #define __underlying_strncpy __builtin_strncpy
> > | ^
> > ./include/linux/fortify-string.h:59:16: note: in expansion of macro '__underlying_strncpy'
> > 59 | return __underlying_strncpy(p, q, size);
> > | ^~~~~~~~~~~~~~~~~~~~
> >
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
>
> Thanks!
> With or without the below comment being addressed
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Thanks!
>
> > Fixes: af40d16042d6 ("Merge v5.15-rc5 into char-misc-next")
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Jiri Prchal <jiri.prchal@aksignal.cz>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> > drivers/misc/eeprom/at25.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
> > index c3305bdda69c..1a19fa5728c8 100644
> > --- a/drivers/misc/eeprom/at25.c
> > +++ b/drivers/misc/eeprom/at25.c
> > @@ -309,7 +309,7 @@ static int at25_fw_to_chip(struct device *dev, struct spi_eeprom *chip)
> > u32 val;
> > int err;
> >
> > - strncpy(chip->name, "at25", sizeof(chip->name));
> > + strscpy(chip->name, "at25", sizeof(chip->name));
> >
> > err = device_property_read_u32(dev, "size", &val);
> > if (err)
> > @@ -370,7 +370,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip)
> > u8 id[FM25_ID_LEN];
> > int i;
> >
> > - strncpy(chip->name, "fm25", sizeof(chip->name));
> > + strscpy(chip->name, "fm25", sizeof(chip->name));
> >
> > /* Get ID of chip */
> > fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN);
> > @@ -440,6 +440,10 @@ static int at25_probe(struct spi_device *spi)
> > return -ENXIO;
> > }
> >
> > + at25 = devm_kzalloc(&spi->dev, sizeof(struct at25_data), GFP_KERNEL);
>
> I would use sizeof(*at25) but I think you restored the exact context.
Yeah, I just restore the chunk exactly as it was.
Greg, should I send a v2 with this adjusted?
-Kees
>
> > + if (!at25)
> > + return -ENOMEM;
> > +
> > mutex_init(&at25->lock);
> > at25->spi = spi;
> > spi_set_drvdata(spi, at25);
> > --
> > 2.30.2
> >
>
>
> --
> With Best Regards,
> Andy Shevchenko
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-01-08 11:36 ` Andy Shevchenko
2022-01-12 20:41 ` Kees Cook
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