count is not checked before kmalloc() call, if it is -1 then kmalloc() returns ZERO_SIZE_PTR. This pointer is then dereferenced. Also one may pass too big count to generate OOM condition. To prevent this limit 'count' maximum value. PAGE_SIZE looks OK. Signed-off-by: Vasiliy Kulikov <segoon@xxxxxxxxxxxx> --- Compile tested only. drivers/gpu/vga/vgaarb.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index c380c65..09e3090 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -836,6 +836,8 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf, int ret_val; int i; + if (count > PAGE_SIZE) + count = PAGE_SIZE; kbuf = kmalloc(count + 1, GFP_KERNEL); if (!kbuf) -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
