Re: [PATCH] ext4: fixed ext4_calculate_overhead() bug.

From: Theodore Ts'o
Date: Wed Nov 28 2012 - 12:45:14 EST


On Wed, Nov 21, 2012 at 04:28:21PM -0800, Vahram Martirosyan wrote:
> The memset operation before check brings to a BUG.
> No need to memset the page with zeroes.
>
> The patch removes the memset call in ext4_calculate_overhead() function.
>
> Found by the Spruce system in cooperation with the KEDR Framework.
>
> Signed-off-by: Vahram Martirosyan <vmartirosyan@xxxxxxxxxxxxxxxx>

Applied, with a slightly rewritten commit description:

ext4: fixed potential NULL dereference in ext4_calculate_overhead()

The memset operation before check can cause a BUG if the memory
allocation failed. Since we are using get_zeroed_age, there is no
need to use memset anyway.

Found by the Spruce system in cooperation with the KEDR Framework.

Signed-off-by: Vahram Martirosyan <vmartirosyan@xxxxxxxxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>

- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/