4.9-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook keescook@chromium.org
commit 4c93496f18ce5044d78e4f7f9e018682a4f44b3d upstream.
This fixes a over-read condition detected by FORTIFY_SOURCE for this line:
memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(skb->cb));
The error was:
In file included from ./include/linux/bitmap.h:8:0, from ./include/linux/cpumask.h:11, from ./include/linux/mm_types_task.h:13, from ./include/linux/mm_types.h:4, from ./include/linux/kmemcheck.h:4, from ./include/linux/skbuff.h:18, from drivers/infiniband/sw/rxe/rxe_resp.c:34: In function 'memcpy', inlined from 'send_atomic_ack.constprop' at drivers/infiniband/sw/rxe/rxe_resp.c:998:2, inlined from 'acknowledge' at drivers/infiniband/sw/rxe/rxe_resp.c:1026:3, inlined from 'rxe_responder' at drivers/infiniband/sw/rxe/rxe_resp.c:1286:10: ./include/linux/string.h:309:4: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter __read_overflow2();
Daniel Micay noted that struct rxe_pkt_info is 32 bytes on 32-bit architectures, but skb->cb is still 64. The memcpy() over-reads 32 bytes. This fixes it by zeroing the unused bytes in skb->cb.
Link: http://lkml.kernel.org/r/1497903987-21002-5-git-send-email-keescook@chromium... Signed-off-by: Kees Cook keescook@chromium.org Cc: Moni Shoua monis@mellanox.com Cc: Doug Ledford dledford@redhat.com Cc: Sean Hefty sean.hefty@intel.com Cc: Daniel Micay danielmicay@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Amit Pundir amit.pundir@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/sw/rxe/rxe_resp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -978,7 +978,9 @@ static int send_atomic_ack(struct rxe_qp free_rd_atomic_resource(qp, res); rxe_advance_resp_resource(qp);
- memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(skb->cb)); + memcpy(SKB_TO_PKT(skb), &ack_pkt, sizeof(ack_pkt)); + memset((unsigned char *)SKB_TO_PKT(skb) + sizeof(ack_pkt), 0, + sizeof(skb->cb) - sizeof(ack_pkt));
res->type = RXE_ATOMIC_MASK; res->atomic.skb = skb;