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From:   Andi Kleen <andi@firstfloor.org>
To:     x86@kernel.org
Cc:     akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
        Andi Kleen <ak@linux.intel.com>, hugues.fruchet@st.com,
        mchehab@s-opensource.com
Subject: [PATCH 10/17] delta: Fix buffer overrun in delta_ipc_open
Date:   Thu, 21 Mar 2019 15:00:02 -0700
Message-Id: <20190321220009.29334-11-andi@firstfloor.org>
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From: Andi Kleen <ak@linux.intel.com>

delta_ipc_open is always called with a single constant string
as name, but it uses a longer memcpy to copy the string to
a different structure. The memcpy would read outside the bounds
of the string, potentially accessing unmapped memory.

Just use strcpy instead after clearing the area.

This fixes a build error with LTO, which can detect this.

Cc: hugues.fruchet@st.com
Cc: mchehab@s-opensource.com
Fixes: 91c83f395fbe [media] st-delta: rpmsg ipc support
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 drivers/media/platform/sti/delta/delta-ipc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/sti/delta/delta-ipc.c b/drivers/media/platform/sti/delta/delta-ipc.c
index a4603d573c34..bd1bbbeedec3 100644
--- a/drivers/media/platform/sti/delta/delta-ipc.c
+++ b/drivers/media/platform/sti/delta/delta-ipc.c
@@ -175,8 +175,8 @@ int delta_ipc_open(struct delta_ctx *pctx, const char *name,
 	msg.ipc_buf_size = ipc_buf_size;
 	msg.ipc_buf_paddr = ctx->ipc_buf->paddr;
 
-	memcpy(msg.name, name, sizeof(msg.name));
-	msg.name[sizeof(msg.name) - 1] = 0;
+	memset(msg.name, 0, sizeof(msg.name));
+	strcpy(msg.name, name);
 
 	msg.param_size = param->size;
 	memcpy(ctx->ipc_buf->vaddr, param->data, msg.param_size);
-- 
2.20.1