From: Kees Cook <keescook@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>,
Moni Shoua <monis@mellanox.com>,
Doug Ledford <dledford@redhat.com>,
Sean Hefty <sean.hefty@intel.com>,
Daniel Micay <danielmicay@gmail.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 6/6] IB/rxe: Do not copy extra stack memory to skb
Date: Mon, 5 Jun 2017 21:52:35 -0700 [thread overview]
Message-ID: <1496724755-104187-7-git-send-email-keescook@chromium.org> (raw)
In-Reply-To: <1496724755-104187-1-git-send-email-keescook@chromium.org>
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.
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>
---
drivers/infiniband/sw/rxe/rxe_resp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index 23039768f541..be944d5aa9af 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -995,7 +995,9 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
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;
--
2.7.4
prev parent reply other threads:[~2017-06-06 4:53 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-06 4:52 [PATCH] FORTIFY_SOURCE build fixes Kees Cook
2017-06-06 4:52 ` [PATCH 1/6] arm64, vdso: Define vdso_{start,end} as array Kees Cook
2017-06-06 9:43 ` Catalin Marinas
2017-06-06 9:49 ` Will Deacon
2017-06-06 16:11 ` Kees Cook
2017-06-06 4:52 ` [PATCH 2/6] efi: Avoid fortify checks in EFI stub Kees Cook
2017-06-06 17:13 ` Ard Biesheuvel
2017-06-06 17:17 ` Mark Rutland
2017-06-07 3:12 ` Kees Cook
2017-06-07 8:54 ` Ard Biesheuvel
2017-06-08 2:37 ` Kees Cook
2017-06-09 9:01 ` Ard Biesheuvel
2017-06-16 9:14 ` Ard Biesheuvel
2017-06-07 9:27 ` Mark Rutland
2017-06-06 4:52 ` [PATCH 3/6] x86/power/64: Use char arrays for asm function names Kees Cook
2017-06-06 4:52 ` [PATCH 4/6] kexec_file: Adjust declaration of kexec_purgatory Kees Cook
2017-06-06 4:52 ` [PATCH 5/6] staging/rts5208: Fix read overflow in memcpy Kees Cook
2017-06-06 4:52 ` Kees Cook [this message]
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