From c56affafdd29eb9764b0e35e3434cc06f6bc3781 Mon Sep 17 00:00:00 2001 From: Inaky Perez-Gonzalez Date: Wed, 20 May 2009 17:16:05 -0700 Subject: [PATCH] wimax/i2400m: fix panic/warnings caused by missed check on empty TX message In some situations, when a new TX message header is started, there might be no space for data payloads. In this case the message is left with zero payloads and the i2400m_tx_close() function has just to mark it as "to skip". If it tries to go ahead it will overwrite things because there is no space to add padding as defined by the bus-specific layer. This can cause buffer overruns and in some stress cases, panics. Found and diagnosed by Cindy H. Kao. Signed-off-by: Inaky Perez-Gonzalez --- drivers/net/wimax/i2400m/tx.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/net/wimax/i2400m/tx.c b/drivers/net/wimax/i2400m/tx.c index a635fd720f3e..7c46c05a5866 100644 --- a/drivers/net/wimax/i2400m/tx.c +++ b/drivers/net/wimax/i2400m/tx.c @@ -474,10 +474,18 @@ void i2400m_tx_close(struct i2400m *i2400m) struct i2400m_msg_hdr *tx_msg_moved; size_t aligned_size, padding, hdr_size; void *pad_buf; + unsigned num_pls; if (tx_msg->size & I2400M_TX_SKIP) /* a skipper? nothing to do */ goto out; - + num_pls = le16_to_cpu(tx_msg->num_pls); + /* We can get this situation when a new message was started + * and there was no space to add payloads before hitting the + tail (and taking padding into consideration). */ + if (num_pls == 0) { + tx_msg->size |= I2400M_TX_SKIP; + goto out; + } /* Relocate the message header * * Find the current header size, align it to 16 and if we need