[email protected] wrote:
> The patch titled
> eepro100: Avoid potential NULL pointer deref in speedo_init_rx_ring()
> has been removed from the -mm tree. Its filename was
> eepro100-avoid-potential-null-pointer-deref-in-speedo_init_rx_ring.patch
>
> This patch was dropped because an updated version will be merged
>
> ------------------------------------------------------
> Subject: eepro100: Avoid potential NULL pointer deref in speedo_init_rx_ring()
> From: Jesper Juhl <[email protected]>
>
> In a low memory situation, if you are very unlucky, the speedo_init_rx_ring()
> function may cause a NULL pointer deref.
>
> The problem is in the case where we can't allocate even a single skb for
> the RX ring. In this case 'last_rxf' will be NULL when we break out of
> the loop and the line
> last_rxf->status = cpu_to_le32(0xC0000002); /* '2' is flag value only. */
> will cause a NULL pointer dereference.
>
> To fix this properly we need to be return an error from speedo_init_rx_ring()
> and have the caller (speedo_open()) catch and propagate the error, as well as
> undo anything done to setup the device so far.
>
> This patch adds a check to catch the unlucky case of not even a single skb
> being available and adds code in the caller to catch the error and release the
> device properly.
>
> For a user who hits this problem, this makes the difference between her device
> not being opened and a kernel crash. Clearly a non functional NIC if
> preferable to a kernel crash - especially since setting up the device can
> easily be retried later after freeing up some memory; a kernel crash is not as
> easy to recover from.
>
> The problem was initially spotted by the Coverity checker.
>
> Signed-off-by: Jesper Juhl <[email protected]>
> Signed-off-by: Andrew Morton <[email protected]>
is this actually a problem? everybody should be running e100. I'm surprised to see
a patch for eepro100, just before it gets removed...
Auke
On 01/10/2007, Kok, Auke <[email protected]> wrote:
...
>
> is this actually a problem? everybody should be running e100. I'm surprised to see
> a patch for eepro100, just before it gets removed...
>
The patch is actually about a year old, it just never got merged. And
IMHO, as long as the driver is in the tree it makes sense to apply
fixes to it.
--
Jesper Juhl <[email protected]>
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