From: Finn Thain <fthain@telegraphics.com.au>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 04/10] via-cuda: Prevent read buffer overflow
Date: Thu, 1 Dec 2016 01:09:33 -0500 (EST) [thread overview]
Message-ID: <99a2b46bcc2885ee9ad790bb2fc3305ac1bbc81c.1480572271.git.fthain@telegraphics.com.au> (raw)
In-Reply-To: <cover.1480572271.git.fthain@telegraphics.com.au>
If the Cuda driver does not enter the 'read_done' state for some
reason, it may continue in the 'reading' state until the buffer
overflows. Add a bounds check to prevent this.
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
drivers/macintosh/via-cuda.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c
index 64626d2..acf3a95 100644
--- a/drivers/macintosh/via-cuda.c
+++ b/drivers/macintosh/via-cuda.c
@@ -470,6 +470,8 @@ cuda_poll(void)
}
EXPORT_SYMBOL(cuda_poll);
+#define ARRAY_FULL(a, p) ((p) - (a) == ARRAY_SIZE(a))
+
static irqreturn_t
cuda_interrupt(int irq, void *arg)
{
@@ -558,7 +560,11 @@ cuda_interrupt(int irq, void *arg)
break;
case reading:
- *reply_ptr++ = in_8(&via[SR]);
+ if (reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr)
+ : ARRAY_FULL(cuda_rbuf, reply_ptr))
+ (void)in_8(&via[SR]);
+ else
+ *reply_ptr++ = in_8(&via[SR]);
if (!TREQ_asserted(status)) {
/* that's all folks */
negate_TIP_and_TACK();
--
2.7.3
next prev parent reply other threads:[~2016-12-01 6:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-01 6:09 [PATCH 00/10] Replace via-maciisi with via-cuda driver Finn Thain
2016-12-01 6:09 ` [PATCH 05/10] via-cuda: Fix re-initialization of reply_ptr and reading_reply Finn Thain
2016-12-01 6:09 ` [PATCH 03/10] via-cuda: Add TREQ, TIP and TACK signal helpers Finn Thain
2016-12-01 6:09 ` [PATCH 07/10] via-cuda: Use spinlock_irq_save/restore instead of enable/disable_irq Finn Thain
2016-12-01 6:09 ` [PATCH 02/10] via-cuda: Remove redundant temporary variable Finn Thain
2016-12-01 6:09 ` [PATCH 01/10] via-cuda: Cleanup printk calls Finn Thain
2016-12-01 6:09 ` [PATCH 06/10] via-cuda: Avoid TREQ race condition Finn Thain
2016-12-01 6:09 ` Finn Thain [this message]
2016-12-01 6:09 ` [PATCH 10/10] m68k/mac: Replace via-maciisi driver with via-cuda driver Finn Thain
2016-12-01 6:09 ` [PATCH 08/10] via-cuda: Initialize data_index early and increment consistently Finn Thain
2016-12-01 6:09 ` [PATCH 09/10] via-cuda: Add support for Egret system controller Finn Thain
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