| Message ID | 20200821010333.20436-1-mmayer@broadcom.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | memory: brcmstb_dpfe: fix array index out of bounds | expand |
On 8/20/2020 6:03 PM, Markus Mayer wrote: > We would overrun the error_text array if we hit a TIMEOUT condition, > because we were using the error code "ETIMEDOUT" (which is 110) as an > array index. > > We fix the problem by correcting the array index and by providing a > function to retrieve error messages rather than accessing the array > directly. The function includes a bounds check that prevents the array > from being overrun. > > Signed-off-by: Markus Mayer <mmayer@broadcom.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Fixes: 2f330caff577 ("memory: brcmstb: Add driver for DPFE") Reported-by: Colin Ian King <colin.king@canonical.com> (Colin, was there a specific coverity ID you wanted to use?)
Hi Markus,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.9-rc1 next-20200820]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Markus-Mayer/memory-brcmstb_dpfe-fix-array-index-out-of-bounds/20200821-090533
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git da2968ff879b9e74688cdc658f646971991d2c56
config: arm-defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> drivers/memory/brcmstb_dpfe.c:305:8: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
305 | static const char * const get_error_text(unsigned int i)
| ^~~~~
# https://github.com/0day-ci/linux/commit/a2de88715f98369b7e4478457a6455c3e2c72725
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Markus-Mayer/memory-brcmstb_dpfe-fix-array-index-out-of-bounds/20200821-090533
git checkout a2de88715f98369b7e4478457a6455c3e2c72725
vim +305 drivers/memory/brcmstb_dpfe.c
304
> 305 static const char * const get_error_text(unsigned int i)
306 {
307 static const char * const error_text[] = {
308 "Success", "Header code incorrect",
309 "Unknown command or argument", "Incorrect checksum",
310 "Malformed command", "Timed out", "Unknown error",
311 };
312
313 if (unlikely(i >= ARRAY_SIZE(error_text)))
314 i = ARRAY_SIZE(error_text) - 1;
315
316 return error_text[i];
317 }
318
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
On Thu, Aug 20, 2020 at 06:03:33PM -0700, Markus Mayer wrote: > We would overrun the error_text array if we hit a TIMEOUT condition, > because we were using the error code "ETIMEDOUT" (which is 110) as an > array index. > > We fix the problem by correcting the array index and by providing a > function to retrieve error messages rather than accessing the array > directly. The function includes a bounds check that prevents the array > from being overrun. > > Signed-off-by: Markus Mayer <mmayer@broadcom.com> > --- > > This patch was prepared in response to https://lkml.org/lkml/2020/8/18/505. > > drivers/memory/brcmstb_dpfe.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) > > diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c > index 81abc4a98a27..a986a849f58e 100644 > --- a/drivers/memory/brcmstb_dpfe.c > +++ b/drivers/memory/brcmstb_dpfe.c > @@ -190,11 +190,6 @@ struct brcmstb_dpfe_priv { > struct mutex lock; > }; > > -static const char * const error_text[] = { > - "Success", "Header code incorrect", "Unknown command or argument", > - "Incorrect checksum", "Malformed command", "Timed out", > -}; > - > /* > * Forward declaration of our sysfs attribute functions, so we can declare the > * attribute data structures early. > @@ -307,6 +302,20 @@ static const struct dpfe_api dpfe_api_v3 = { > }, > }; > > +static const char * const get_error_text(unsigned int i) The pointer itself is returned by value and you cannot return a const value. I mean, you can but it does not have an effect. Only pointed memory should be const (const const char*). Best regards, Krzysztof > +{ > + static const char * const error_text[] = { > + "Success", "Header code incorrect", > + "Unknown command or argument", "Incorrect checksum", > + "Malformed command", "Timed out", "Unknown error", > + }; > + > + if (unlikely(i >= ARRAY_SIZE(error_text))) > + i = ARRAY_SIZE(error_text) - 1; > + > + return error_text[i]; > +} > + > static bool is_dcpu_enabled(struct brcmstb_dpfe_priv *priv) > { > u32 val; > @@ -446,7 +455,7 @@ static int __send_command(struct brcmstb_dpfe_priv *priv, unsigned int cmd, > } > if (resp != 0) { > mutex_unlock(&priv->lock); > - return -ETIMEDOUT; > + return -ffs(DCPU_RET_ERR_TIMEDOUT); > } > > /* Compute checksum over the message */ > @@ -695,7 +704,7 @@ static ssize_t generic_show(unsigned int command, u32 response[], > > ret = __send_command(priv, command, response); > if (ret < 0) > - return sprintf(buf, "ERROR: %s\n", error_text[-ret]); > + return sprintf(buf, "ERROR: %s\n", get_error_text(-ret)); > > return 0; > } > -- > 2.17.1 >
On Thu, 20 Aug 2020 at 22:40, Krzysztof Kozlowski <krzk@kernel.org> wrote: > > On Thu, Aug 20, 2020 at 06:03:33PM -0700, Markus Mayer wrote: > > We would overrun the error_text array if we hit a TIMEOUT condition, > > because we were using the error code "ETIMEDOUT" (which is 110) as an > > array index. > > > > We fix the problem by correcting the array index and by providing a > > function to retrieve error messages rather than accessing the array > > directly. The function includes a bounds check that prevents the array > > from being overrun. > > > > Signed-off-by: Markus Mayer <mmayer@broadcom.com> > > --- > > > > This patch was prepared in response to https://lkml.org/lkml/2020/8/18/505. > > > > drivers/memory/brcmstb_dpfe.c | 23 ++++++++++++++++------- > > 1 file changed, 16 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c > > index 81abc4a98a27..a986a849f58e 100644 > > --- a/drivers/memory/brcmstb_dpfe.c > > +++ b/drivers/memory/brcmstb_dpfe.c > > @@ -190,11 +190,6 @@ struct brcmstb_dpfe_priv { > > struct mutex lock; > > }; > > > > -static const char * const error_text[] = { > > - "Success", "Header code incorrect", "Unknown command or argument", > > - "Incorrect checksum", "Malformed command", "Timed out", > > -}; > > - > > /* > > * Forward declaration of our sysfs attribute functions, so we can declare the > > * attribute data structures early. > > @@ -307,6 +302,20 @@ static const struct dpfe_api dpfe_api_v3 = { > > }, > > }; > > > > +static const char * const get_error_text(unsigned int i) > > The pointer itself is returned by value and you cannot return a const > value. I mean, you can but it does not have an effect. Only pointed > memory should be const (const const char*). v2 is on the way. Regards, -Markus > > +{ > > + static const char * const error_text[] = { > > + "Success", "Header code incorrect", > > + "Unknown command or argument", "Incorrect checksum", > > + "Malformed command", "Timed out", "Unknown error", > > + }; > > + > > + if (unlikely(i >= ARRAY_SIZE(error_text))) > > + i = ARRAY_SIZE(error_text) - 1; > > + > > + return error_text[i]; > > +} > > + > > static bool is_dcpu_enabled(struct brcmstb_dpfe_priv *priv) > > { > > u32 val; > > @@ -446,7 +455,7 @@ static int __send_command(struct brcmstb_dpfe_priv *priv, unsigned int cmd, > > } > > if (resp != 0) { > > mutex_unlock(&priv->lock); > > - return -ETIMEDOUT; > > + return -ffs(DCPU_RET_ERR_TIMEDOUT); > > } > > > > /* Compute checksum over the message */ > > @@ -695,7 +704,7 @@ static ssize_t generic_show(unsigned int command, u32 response[], > > > > ret = __send_command(priv, command, response); > > if (ret < 0) > > - return sprintf(buf, "ERROR: %s\n", error_text[-ret]); > > + return sprintf(buf, "ERROR: %s\n", get_error_text(-ret)); > > > > return 0; > > } > > -- > > 2.17.1 > >
diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c index 81abc4a98a27..a986a849f58e 100644 --- a/drivers/memory/brcmstb_dpfe.c +++ b/drivers/memory/brcmstb_dpfe.c @@ -190,11 +190,6 @@ struct brcmstb_dpfe_priv { struct mutex lock; }; -static const char * const error_text[] = { - "Success", "Header code incorrect", "Unknown command or argument", - "Incorrect checksum", "Malformed command", "Timed out", -}; - /* * Forward declaration of our sysfs attribute functions, so we can declare the * attribute data structures early. @@ -307,6 +302,20 @@ static const struct dpfe_api dpfe_api_v3 = { }, }; +static const char * const get_error_text(unsigned int i) +{ + static const char * const error_text[] = { + "Success", "Header code incorrect", + "Unknown command or argument", "Incorrect checksum", + "Malformed command", "Timed out", "Unknown error", + }; + + if (unlikely(i >= ARRAY_SIZE(error_text))) + i = ARRAY_SIZE(error_text) - 1; + + return error_text[i]; +} + static bool is_dcpu_enabled(struct brcmstb_dpfe_priv *priv) { u32 val; @@ -446,7 +455,7 @@ static int __send_command(struct brcmstb_dpfe_priv *priv, unsigned int cmd, } if (resp != 0) { mutex_unlock(&priv->lock); - return -ETIMEDOUT; + return -ffs(DCPU_RET_ERR_TIMEDOUT); } /* Compute checksum over the message */ @@ -695,7 +704,7 @@ static ssize_t generic_show(unsigned int command, u32 response[], ret = __send_command(priv, command, response); if (ret < 0) - return sprintf(buf, "ERROR: %s\n", error_text[-ret]); + return sprintf(buf, "ERROR: %s\n", get_error_text(-ret)); return 0; }
We would overrun the error_text array if we hit a TIMEOUT condition, because we were using the error code "ETIMEDOUT" (which is 110) as an array index. We fix the problem by correcting the array index and by providing a function to retrieve error messages rather than accessing the array directly. The function includes a bounds check that prevents the array from being overrun. Signed-off-by: Markus Mayer <mmayer@broadcom.com> --- This patch was prepared in response to https://lkml.org/lkml/2020/8/18/505. drivers/memory/brcmstb_dpfe.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-)