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| author | Florian Fainelli <f.fainelli@gmail.com> | 2016-12-05 06:22:05 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-05 23:35:39 +0300 |
| commit | c823abac17926767fb50175e098f087a6ac684c3 (patch) | |
| tree | 82887ccb88651b5a77598d26a65eb555ab21ae38 /drivers/net/ethernet/cirrus | |
| parent | 34e0f2c2d82d7d939bfa249672311050b3b537f1 (diff) | |
| download | linux-c823abac17926767fb50175e098f087a6ac684c3.tar.xz | |
net: ep93xx_eth: Do not crash unloading module
When we unload the ep93xx_eth, whether we have opened the network
interface or not, we will either hit a kernel paging request error, or a
simple NULL pointer de-reference because:
- if ep93xx_open has been called, we have created a valid DMA mapping
for ep->descs, when we call ep93xx_stop, we also call
ep93xx_free_buffers, ep->descs now has a stale value
- if ep93xx_open has not been called, we have a NULL pointer for
ep->descs, so performing any operation against that address just won't
work
Fix this by adding a NULL pointer check for ep->descs which means that
ep93xx_free_buffers() was able to successfully tear down the descriptors
and free the DMA cookie as well.
Fixes: 1d22e05df818 ("[PATCH] Cirrus Logic ep93xx ethernet driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/cirrus')
| -rw-r--r-- | drivers/net/ethernet/cirrus/ep93xx_eth.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/net/ethernet/cirrus/ep93xx_eth.c b/drivers/net/ethernet/cirrus/ep93xx_eth.c index de9f7c97d916..9a161e981529 100644 --- a/drivers/net/ethernet/cirrus/ep93xx_eth.c +++ b/drivers/net/ethernet/cirrus/ep93xx_eth.c @@ -468,6 +468,9 @@ static void ep93xx_free_buffers(struct ep93xx_priv *ep) struct device *dev = ep->dev->dev.parent; int i; + if (!ep->descs) + return; + for (i = 0; i < RX_QUEUE_ENTRIES; i++) { dma_addr_t d; @@ -490,6 +493,7 @@ static void ep93xx_free_buffers(struct ep93xx_priv *ep) dma_free_coherent(dev, sizeof(struct ep93xx_descs), ep->descs, ep->descs_dma_addr); + ep->descs = NULL; } static int ep93xx_alloc_buffers(struct ep93xx_priv *ep) |