From: Kees Cook <keescook@xxxxxxxxxxxx>
In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally reading across neighboring array fields.
Add a wrapping struct to serve as the memcpy() source so the compiler
can perform appropriate bounds checking, avoiding this future warning:
In function '__fortify_memcpy',
inlined from 'iucv_message_pending' at net/iucv/iucv.c:1663:4:
./include/linux/fortify-string.h:246:4: error: call to '__read_overflow2_field' declared with attribute error: detected read beyond size of field (2nd parameter)
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
---
net/iucv/iucv.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index 349c6ac3313f..e6795d5a546a 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -1635,14 +1635,16 @@ struct iucv_message_pending {
u8 iptype;
u32 ipmsgid;
u32 iptrgcls;
- union {
- u32 iprmmsg1_u32;
- u8 iprmmsg1[4];
- } ln1msg1;
- union {
- u32 ipbfln1f;
- u8 iprmmsg2[4];
- } ln1msg2;
+ struct {
+ union {
+ u32 iprmmsg1_u32;
+ u8 iprmmsg1[4];
+ } ln1msg1;
+ union {
+ u32 ipbfln1f;
+ u8 iprmmsg2[4];
+ } ln1msg2;
+ } rmmsg;
u32 res1[3];
u32 ipbfln2f;
u8 ippollfg;
@@ -1660,10 +1662,10 @@ static void iucv_message_pending(struct iucv_irq_data *data)
msg.id = imp->ipmsgid;
msg.class = imp->iptrgcls;
if (imp->ipflags1 & IUCV_IPRMDATA) {
- memcpy(msg.rmmsg, imp->ln1msg1.iprmmsg1, 8);
+ memcpy(msg.rmmsg, &imp->rmmsg, 8);
msg.length = 8;
} else
- msg.length = imp->ln1msg2.ipbfln1f;
+ msg.length = imp->rmmsg.ln1msg2.ipbfln1f;
msg.reply_size = imp->ipbfln2f;
path->handler->message_pending(path, &msg);
}
--
2.25.1
