| Message ID | 20200822205000.15841-1-mmayer@broadcom.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] memory: brcmstb_dpfe: fix array index out of bounds | expand |
On Sat, Aug 22, 2020 at 01:50:00PM -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. > > This patch was prepared in response to > https://lkml.org/lkml/2020/8/18/505. > > 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> > --- > > Changes since v2: > - Added "Fixes:" and "Reported-by:" > - Fixed "From" address > - No changes to the code > > Changes since v1: > - Added link of the coverity report to the commit message. > - Added Florian's ack. > - Removed second "const" from get_error_text() return type > (thanks to the kernel test robot). > > drivers/memory/brcmstb_dpfe.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) "From" and SoB look good now. Thanks, applied. Best regards, Krzysztof
diff --git a/drivers/memory/brcmstb_dpfe.c b/drivers/memory/brcmstb_dpfe.c index e08528b12cbd..dcf50bb8dd69 100644 --- a/drivers/memory/brcmstb_dpfe.c +++ b/drivers/memory/brcmstb_dpfe.c @@ -188,11 +188,6 @@ 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 *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; @@ -445,7 +454,7 @@ 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. This patch was prepared in response to https://lkml.org/lkml/2020/8/18/505. 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> --- Changes since v2: - Added "Fixes:" and "Reported-by:" - Fixed "From" address - No changes to the code Changes since v1: - Added link of the coverity report to the commit message. - Added Florian's ack. - Removed second "const" from get_error_text() return type (thanks to the kernel test robot). drivers/memory/brcmstb_dpfe.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-)