* [PATCH v3 09/11] powerpc/papr_scm: Return the string length from the sysfs show functions [not found] <20260930235231.out.387-kees@kernel.org> @ 2026-09-30 23:52 ` Kees Cook 2026-10-01 4:17 ` Madhavan Srinivasan 0 siblings, 1 reply; 3+ messages in thread From: Kees Cook @ 2026-09-30 23:52 UTC (permalink / raw) To: Bill Wendling Cc: Kees Cook, Christophe Leroy (CS GROUP), Uwe Kleine-König, linuxppc-dev, Madhavan Srinivasan, Michael Ellerman, Nicholas Piggin, Shivaprasad G Bhat, Thorsten Blum, Andy Shevchenko, Steven Rostedt, nikitash.mariiaw, Greg KH, linux-kernel, linux-hardening perf_stats_show() and flags_show() build their output with a seq_buf and return seq_buf_used(), which may include the trailing NUL byte when the seq_buf has overflowed. Use seq_buf_strlen() instead. Build tested ARCH=powerpc ppc64_defconfig with GCC powerpc64-linux-gnu 16.1.0: arch/powerpc/platforms/pseries/papr_scm.o Assisted-by: LLM Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Kees Cook <kees@kernel.org> --- arch/powerpc/platforms/pseries/papr_scm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index 75da96c08cdd..b03cfd8528f5 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -1108,7 +1108,7 @@ static ssize_t perf_stats_show(struct device *dev, free_stats: kfree(stats); - return rc ? rc : (ssize_t)seq_buf_used(&s); + return rc ?: (ssize_t)seq_buf_strlen(&s); } static DEVICE_ATTR_ADMIN_RO(perf_stats); @@ -1150,7 +1150,7 @@ static ssize_t flags_show(struct device *dev, if (seq_buf_used(&s)) seq_buf_printf(&s, "\n"); - return seq_buf_used(&s); + return seq_buf_strlen(&s); } DEVICE_ATTR_RO(flags); -- 2.34.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v3 09/11] powerpc/papr_scm: Return the string length from the sysfs show functions 2026-09-30 23:52 ` [PATCH v3 09/11] powerpc/papr_scm: Return the string length from the sysfs show functions Kees Cook @ 2026-10-01 4:17 ` Madhavan Srinivasan 2026-10-02 7:54 ` Kees Cook 0 siblings, 1 reply; 3+ messages in thread From: Madhavan Srinivasan @ 2026-10-01 4:17 UTC (permalink / raw) To: Kees Cook, Bill Wendling Cc: Christophe Leroy (CS GROUP), Uwe Kleine-König, linuxppc-dev, Michael Ellerman, Nicholas Piggin, Shivaprasad G Bhat, Thorsten Blum, Andy Shevchenko, Steven Rostedt, nikitash.mariiaw, Greg KH, linux-kernel, linux-hardening On 10/1/26 5:22 AM, Kees Cook wrote: > perf_stats_show() and flags_show() build their output with a seq_buf > and return seq_buf_used(), which may include the trailing NUL byte > when the seq_buf has overflowed. Use seq_buf_strlen() instead. > > Build tested ARCH=powerpc ppc64_defconfig with GCC powerpc64-linux-gnu > 16.1.0: > arch/powerpc/platforms/pseries/papr_scm.o > > Assisted-by: LLM > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Kees Cook <kees@kernel.org> > --- > arch/powerpc/platforms/pseries/papr_scm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c > index 75da96c08cdd..b03cfd8528f5 100644 > --- a/arch/powerpc/platforms/pseries/papr_scm.c > +++ b/arch/powerpc/platforms/pseries/papr_scm.c > @@ -1108,7 +1108,7 @@ static ssize_t perf_stats_show(struct device *dev, > > free_stats: > kfree(stats); > - return rc ? rc : (ssize_t)seq_buf_used(&s); > + return rc ?: (ssize_t)seq_buf_strlen(&s); > } > static DEVICE_ATTR_ADMIN_RO(perf_stats); > > @@ -1150,7 +1150,7 @@ static ssize_t flags_show(struct device *dev, > if (seq_buf_used(&s)) this can also be seq_buf_strlen instead > seq_buf_printf(&s, "\n"); > > - return seq_buf_used(&s); > + return seq_buf_strlen(&s); > } > DEVICE_ATTR_RO(flags); > ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3 09/11] powerpc/papr_scm: Return the string length from the sysfs show functions 2026-10-01 4:17 ` Madhavan Srinivasan @ 2026-10-02 7:54 ` Kees Cook 0 siblings, 0 replies; 3+ messages in thread From: Kees Cook @ 2026-10-02 7:54 UTC (permalink / raw) To: Madhavan Srinivasan Cc: Bill Wendling, Christophe Leroy (CS GROUP), Uwe Kleine-König, linuxppc-dev, Michael Ellerman, Nicholas Piggin, Shivaprasad G Bhat, Thorsten Blum, Andy Shevchenko, Steven Rostedt, nikitash.mariiaw, Greg KH, linux-kernel, linux-hardening On Thu, Oct 01, 2026 at 09:47:56AM +0530, Madhavan Srinivasan wrote: > > On 10/1/26 5:22 AM, Kees Cook wrote: > > perf_stats_show() and flags_show() build their output with a seq_buf > > and return seq_buf_used(), which may include the trailing NUL byte > > when the seq_buf has overflowed. Use seq_buf_strlen() instead. > > > > Build tested ARCH=powerpc ppc64_defconfig with GCC powerpc64-linux-gnu > > 16.1.0: > > arch/powerpc/platforms/pseries/papr_scm.o > > > > Assisted-by: LLM > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > Signed-off-by: Kees Cook <kees@kernel.org> > > --- > > arch/powerpc/platforms/pseries/papr_scm.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c > > index 75da96c08cdd..b03cfd8528f5 100644 > > --- a/arch/powerpc/platforms/pseries/papr_scm.c > > +++ b/arch/powerpc/platforms/pseries/papr_scm.c > > @@ -1108,7 +1108,7 @@ static ssize_t perf_stats_show(struct device *dev, > > free_stats: > > kfree(stats); > > - return rc ? rc : (ssize_t)seq_buf_used(&s); > > + return rc ?: (ssize_t)seq_buf_strlen(&s); > > } > > static DEVICE_ATTR_ADMIN_RO(perf_stats); > > @@ -1150,7 +1150,7 @@ static ssize_t flags_show(struct device *dev, > > if (seq_buf_used(&s)) > > this can also be seq_buf_strlen instead It could be, yeah. I left it because it seemed be more about "did we touch this at all?" But it's honestly all the same. I will respin with it changed too. > > > seq_buf_printf(&s, "\n"); > > - return seq_buf_used(&s); > > + return seq_buf_strlen(&s); > > } > > DEVICE_ATTR_RO(flags); -- Kees Cook ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-10-02 7:54 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <20260930235231.out.387-kees@kernel.org>
2026-09-30 23:52 ` [PATCH v3 09/11] powerpc/papr_scm: Return the string length from the sysfs show functions Kees Cook
2026-10-01 4:17 ` Madhavan Srinivasan
2026-10-02 7:54 ` Kees Cook
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox