* [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read @ 2015-04-17 6:04 Heinrich Schuchardt 2015-04-21 1:32 ` Peter Chen 0 siblings, 1 reply; 7+ messages in thread From: Heinrich Schuchardt @ 2015-04-17 6:04 UTC (permalink / raw) To: Peter Chen Cc: Greg Kroah-Hartman, linux-usb, linux-kernel, Heinrich Schuchardt A string written by the user may not be zero terminated. sscanf may read memory beyond the buffer if no zero byte is found. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> --- drivers/usb/chipidea/debug.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c index dfb05ed..ef08af3 100644 --- a/drivers/usb/chipidea/debug.c +++ b/drivers/usb/chipidea/debug.c @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, char buf[32]; int ret; - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) + count = min_t(size_t, sizeof(buf) - 1, count); + if (copy_from_user(buf, ubuf, count)) return -EFAULT; + /* sscanf requires a zero terminated string */ + buf[count] = 0; + if (sscanf(buf, "%u", &mode) != 1) return -EINVAL; -- 2.1.4 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read 2015-04-17 6:04 [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read Heinrich Schuchardt @ 2015-04-21 1:32 ` Peter Chen 2015-04-21 19:25 ` Heinrich Schuchardt 0 siblings, 1 reply; 7+ messages in thread From: Peter Chen @ 2015-04-21 1:32 UTC (permalink / raw) To: Heinrich Schuchardt; +Cc: Greg Kroah-Hartman, linux-usb, linux-kernel On Fri, Apr 17, 2015 at 08:04:13AM +0200, Heinrich Schuchardt wrote: > A string written by the user may not be zero terminated. > > sscanf may read memory beyond the buffer if no zero byte > is found. > > Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > --- > drivers/usb/chipidea/debug.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c > index dfb05ed..ef08af3 100644 > --- a/drivers/usb/chipidea/debug.c > +++ b/drivers/usb/chipidea/debug.c > @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, > char buf[32]; > int ret; > > - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) > + count = min_t(size_t, sizeof(buf) - 1, count); > + if (copy_from_user(buf, ubuf, count)) > return -EFAULT; Any reasons to change above? > > + /* sscanf requires a zero terminated string */ > + buf[count] = 0; > + I prefer using '\0' > if (sscanf(buf, "%u", &mode) != 1) > return -EINVAL; > > -- > 2.1.4 > -- Best Regards, Peter Chen ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read 2015-04-21 1:32 ` Peter Chen @ 2015-04-21 19:25 ` Heinrich Schuchardt 2015-04-22 1:26 ` Peter Chen 0 siblings, 1 reply; 7+ messages in thread From: Heinrich Schuchardt @ 2015-04-21 19:25 UTC (permalink / raw) To: Peter Chen; +Cc: Greg Kroah-Hartman, linux-usb, linux-kernel Hello Peter, thanks for reviewing. On 21.04.2015 03:32, Peter Chen wrote: > On Fri, Apr 17, 2015 at 08:04:13AM +0200, Heinrich Schuchardt wrote: >> A string written by the user may not be zero terminated. >> >> sscanf may read memory beyond the buffer if no zero byte >> is found. >> >> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> >> --- >> drivers/usb/chipidea/debug.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c >> index dfb05ed..ef08af3 100644 >> --- a/drivers/usb/chipidea/debug.c >> +++ b/drivers/usb/chipidea/debug.c >> @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, >> char buf[32]; >> int ret; >> >> - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) >> + count = min_t(size_t, sizeof(buf) - 1, count); >> + if (copy_from_user(buf, ubuf, count)) >> return -EFAULT; > > Any reasons to change above? Otherwise we would have two lines with the term min_t(size_t, sizeof(buf) - 1, count). This would make the code harder to read. >> >> + /* sscanf requires a zero terminated string */ >> + buf[count] = 0; >> + > > I prefer using '\0' If you confirm the rest of the patch is ok, I will send an updated patch. Best regards Heinrich > >> if (sscanf(buf, "%u", &mode) != 1) >> return -EINVAL; >> ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read 2015-04-21 19:25 ` Heinrich Schuchardt @ 2015-04-22 1:26 ` Peter Chen 2015-04-27 18:25 ` Heinrich Schuchardt 0 siblings, 1 reply; 7+ messages in thread From: Peter Chen @ 2015-04-22 1:26 UTC (permalink / raw) To: Heinrich Schuchardt; +Cc: Greg Kroah-Hartman, linux-usb, linux-kernel On Tue, Apr 21, 2015 at 09:25:41PM +0200, Heinrich Schuchardt wrote: > Hello Peter, > > thanks for reviewing. > > On 21.04.2015 03:32, Peter Chen wrote: > > On Fri, Apr 17, 2015 at 08:04:13AM +0200, Heinrich Schuchardt wrote: > >> A string written by the user may not be zero terminated. > >> > >> sscanf may read memory beyond the buffer if no zero byte > >> is found. > >> > >> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > >> --- > >> drivers/usb/chipidea/debug.c | 6 +++++- > >> 1 file changed, 5 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c > >> index dfb05ed..ef08af3 100644 > >> --- a/drivers/usb/chipidea/debug.c > >> +++ b/drivers/usb/chipidea/debug.c > >> @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, > >> char buf[32]; > >> int ret; > >> > >> - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) > >> + count = min_t(size_t, sizeof(buf) - 1, count); > >> + if (copy_from_user(buf, ubuf, count)) > >> return -EFAULT; > > > > Any reasons to change above? > > Otherwise we would have two lines with the term > min_t(size_t, sizeof(buf) - 1, count). Sorry, two lines of min_t(..)? Why I can't find it? > > This would make the code harder to read. > > >> > >> + /* sscanf requires a zero terminated string */ > >> + buf[count] = 0; > >> + > > > > I prefer using '\0' > > If you confirm the rest of the patch is ok, I will send an updated patch. > > Best regards > > Heinrich > > > > >> if (sscanf(buf, "%u", &mode) != 1) > >> return -EINVAL; > >> > -- Best Regards, Peter Chen ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read 2015-04-22 1:26 ` Peter Chen @ 2015-04-27 18:25 ` Heinrich Schuchardt 2015-04-28 8:22 ` Peter Chen 0 siblings, 1 reply; 7+ messages in thread From: Heinrich Schuchardt @ 2015-04-27 18:25 UTC (permalink / raw) To: Peter Chen; +Cc: Greg Kroah-Hartman, linux-usb, linux-kernel On 22.04.2015 03:26, Peter Chen wrote: > On Tue, Apr 21, 2015 at 09:25:41PM +0200, Heinrich Schuchardt wrote: >> Hello Peter, >> >> thanks for reviewing. >> >> On 21.04.2015 03:32, Peter Chen wrote: >>> On Fri, Apr 17, 2015 at 08:04:13AM +0200, Heinrich Schuchardt wrote: >>>> A string written by the user may not be zero terminated. >>>> >>>> sscanf may read memory beyond the buffer if no zero byte >>>> is found. >>>> >>>> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> >>>> --- >>>> drivers/usb/chipidea/debug.c | 6 +++++- >>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c >>>> index dfb05ed..ef08af3 100644 >>>> --- a/drivers/usb/chipidea/debug.c >>>> +++ b/drivers/usb/chipidea/debug.c >>>> @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, >>>> char buf[32]; >>>> int ret; >>>> >>>> - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) >>>> + count = min_t(size_t, sizeof(buf) - 1, count); >>>> + if (copy_from_user(buf, ubuf, count)) >>>> return -EFAULT; >>> >>> Any reasons to change above? >> >> Otherwise we would have two lines with the term >> min_t(size_t, sizeof(buf) - 1, count). > > Sorry, two lines of min_t(..)? Why I can't find it? Hello Peter, in my patch I write: count = min_t(size_t, sizeof(buf) - 1, count); if (copy_from_user(buf, ubuf, count)) return -EFAULT; /* sscanf requires a zero terminated string */ buf[count] = 0; Without the first part of the change I would have had to write: if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) return -EFAULT; /* sscanf requires a zero terminated string */ buf[min_t(size_t, sizeof(buf) - 1, count)] = 0; We should do the same calculation "min_t(size_t, sizeof(buf) - 1, count)" only once in the coding. Best regards Heinrich > > >> >> This would make the code harder to read. >> >>>> >>>> + /* sscanf requires a zero terminated string */ >>>> + buf[count] = 0; >>>> + >>> >>> I prefer using '\0' >> >> If you confirm the rest of the patch is ok, I will send an updated patch. >> >> Best regards >> >> Heinrich >> >>> >>>> if (sscanf(buf, "%u", &mode) != 1) >>>> return -EINVAL; >>>> >> > ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read 2015-04-27 18:25 ` Heinrich Schuchardt @ 2015-04-28 8:22 ` Peter Chen 2015-04-28 17:30 ` [PATCH 1/1 v2] " Heinrich Schuchardt 0 siblings, 1 reply; 7+ messages in thread From: Peter Chen @ 2015-04-28 8:22 UTC (permalink / raw) To: Heinrich Schuchardt; +Cc: Greg Kroah-Hartman, linux-usb, linux-kernel On Mon, Apr 27, 2015 at 08:25:12PM +0200, Heinrich Schuchardt wrote: > On 22.04.2015 03:26, Peter Chen wrote: > > On Tue, Apr 21, 2015 at 09:25:41PM +0200, Heinrich Schuchardt wrote: > >> Hello Peter, > >> > >> thanks for reviewing. > >> > >> On 21.04.2015 03:32, Peter Chen wrote: > >>> On Fri, Apr 17, 2015 at 08:04:13AM +0200, Heinrich Schuchardt wrote: > >>>> A string written by the user may not be zero terminated. > >>>> > >>>> sscanf may read memory beyond the buffer if no zero byte > >>>> is found. > >>>> > >>>> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > >>>> --- > >>>> drivers/usb/chipidea/debug.c | 6 +++++- > >>>> 1 file changed, 5 insertions(+), 1 deletion(-) > >>>> > >>>> diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c > >>>> index dfb05ed..ef08af3 100644 > >>>> --- a/drivers/usb/chipidea/debug.c > >>>> +++ b/drivers/usb/chipidea/debug.c > >>>> @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, > >>>> char buf[32]; > >>>> int ret; > >>>> > >>>> - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) > >>>> + count = min_t(size_t, sizeof(buf) - 1, count); > >>>> + if (copy_from_user(buf, ubuf, count)) > >>>> return -EFAULT; > >>> > >>> Any reasons to change above? > >> > >> Otherwise we would have two lines with the term > >> min_t(size_t, sizeof(buf) - 1, count). > > > > Sorry, two lines of min_t(..)? Why I can't find it? > > Hello Peter, > > in my patch I write: > > count = min_t(size_t, sizeof(buf) - 1, count); > if (copy_from_user(buf, ubuf, count)) > return -EFAULT; > > /* sscanf requires a zero terminated string */ > buf[count] = 0; > > Without the first part of the change I would have had to write: > > if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) > return -EFAULT; > > /* sscanf requires a zero terminated string */ > buf[min_t(size_t, sizeof(buf) - 1, count)] = 0; > > We should do the same calculation > "min_t(size_t, sizeof(buf) - 1, count)" > only once in the coding. Oh, yeah. Send your v2 with '\0' change, thanks. Peter > > Best regards > > Heinrich > > > > > > > >> > >> This would make the code harder to read. > >> > >>>> > >>>> + /* sscanf requires a zero terminated string */ > >>>> + buf[count] = 0; > >>>> + > >>> > >>> I prefer using '\0' > >> > >> If you confirm the rest of the patch is ok, I will send an updated patch. > >> > >> Best regards > >> > >> Heinrich > >> > >>> > >>>> if (sscanf(buf, "%u", &mode) != 1) > >>>> return -EINVAL; > >>>> > >> > > > -- Best Regards, Peter Chen ^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH 1/1 v2] drivers/usb/chipidea/debuc.c: avoid out of bound read 2015-04-28 8:22 ` Peter Chen @ 2015-04-28 17:30 ` Heinrich Schuchardt 0 siblings, 0 replies; 7+ messages in thread From: Heinrich Schuchardt @ 2015-04-28 17:30 UTC (permalink / raw) To: Peter Chen Cc: Greg Kroah-Hartman, linux-usb, linux-kernel, Heinrich Schuchardt A string written by the user may not be zero terminated. sscanf may read memory beyond the buffer if no zero byte is found. For testing build with CONFIG_USB_CHIPIDEA=y, CONFIG_USB_CHIPIDEA_DEBUG=y. Version 2: Use '\0' for char constant. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> --- drivers/usb/chipidea/debug.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c index dfb05ed..ef08af3 100644 --- a/drivers/usb/chipidea/debug.c +++ b/drivers/usb/chipidea/debug.c @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, char buf[32]; int ret; - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) + count = min_t(size_t, sizeof(buf) - 1, count); + if (copy_from_user(buf, ubuf, count)) return -EFAULT; + /* sscanf requires a zero terminated string */ + buf[count] = '\0'; + if (sscanf(buf, "%u", &mode) != 1) return -EINVAL; -- 2.1.4 ^ permalink raw reply related [flat|nested] 7+ messages in thread
end of thread, other threads:[~2015-04-28 17:32 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-04-17 6:04 [PATCH 1/1] drivers/usb/chipidea/debuc.c: avoid out of bound read Heinrich Schuchardt 2015-04-21 1:32 ` Peter Chen 2015-04-21 19:25 ` Heinrich Schuchardt 2015-04-22 1:26 ` Peter Chen 2015-04-27 18:25 ` Heinrich Schuchardt 2015-04-28 8:22 ` Peter Chen 2015-04-28 17:30 ` [PATCH 1/1 v2] " Heinrich Schuchardt
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