| Message ID | 20210727205855.411487-4-keescook@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce strict memcpy() bounds checking | expand |
On Tue, Jul 27, 2021 at 01:57:54PM -0700, Kees Cook wrote: > The use of strncpy() is considered deprecated for NUL-terminated > strings[1]. Replace strncpy() with strscpy_pad() (as it seems this case > expects the NUL padding to fill the allocation following the flexible > array). This additionally silences a warning seen when building under > -Warray-bounds: > > ./include/linux/fortify-string.h:38:30: warning: '__builtin_strncpy' offset 24 from the object at '__mptr' is out of the bounds of referenced subobject 'data' with type 'u8[]' {aka 'unsigned char[]'} at offset 24 [-Warray-bounds] > 38 | #define __underlying_strncpy __builtin_strncpy > | ^ > ./include/linux/fortify-string.h:50:9: note: in expansion of macro '__underlying_strncpy' > 50 | return __underlying_strncpy(p, q, size); > | ^~~~~~~~~~~~~~~~~~~~ > drivers/rpmsg/qcom_glink_native.c: In function 'qcom_glink_work': > drivers/rpmsg/qcom_glink_native.c:36:5: note: subobject 'data' declared here > 36 | u8 data[]; > | ^~~~ > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings > > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Thanks -- Gustavo > --- > drivers/rpmsg/qcom_glink_native.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c > index 05533c71b10e..c7b9de655080 100644 > --- a/drivers/rpmsg/qcom_glink_native.c > +++ b/drivers/rpmsg/qcom_glink_native.c > @@ -1440,7 +1440,7 @@ static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid, > } > > rpdev->ept = &channel->ept; > - strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE); > + strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE); > rpdev->src = RPMSG_ADDR_ANY; > rpdev->dst = RPMSG_ADDR_ANY; > rpdev->ops = &glink_device_ops; > -- > 2.30.2 >
diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c index 05533c71b10e..c7b9de655080 100644 --- a/drivers/rpmsg/qcom_glink_native.c +++ b/drivers/rpmsg/qcom_glink_native.c @@ -1440,7 +1440,7 @@ static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid, } rpdev->ept = &channel->ept; - strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE); + strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE); rpdev->src = RPMSG_ADDR_ANY; rpdev->dst = RPMSG_ADDR_ANY; rpdev->ops = &glink_device_ops;
The use of strncpy() is considered deprecated for NUL-terminated strings[1]. Replace strncpy() with strscpy_pad() (as it seems this case expects the NUL padding to fill the allocation following the flexible array). This additionally silences a warning seen when building under -Warray-bounds: ./include/linux/fortify-string.h:38:30: warning: '__builtin_strncpy' offset 24 from the object at '__mptr' is out of the bounds of referenced subobject 'data' with type 'u8[]' {aka 'unsigned char[]'} at offset 24 [-Warray-bounds] 38 | #define __underlying_strncpy __builtin_strncpy | ^ ./include/linux/fortify-string.h:50:9: note: in expansion of macro '__underlying_strncpy' 50 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ drivers/rpmsg/qcom_glink_native.c: In function 'qcom_glink_work': drivers/rpmsg/qcom_glink_native.c:36:5: note: subobject 'data' declared here 36 | u8 data[]; | ^~~~ [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/rpmsg/qcom_glink_native.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)