Messages in this thread Patch in this message | | | Date | Wed, 30 Sep 2009 13:17:09 +0200 | From | Arjan van de Ven <> | Subject | [PATCH] floppy: Add an extra bound check on ioctl arguments |
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From 90d75780b319153d050bb1c0f3f38ce054775615 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven <arjan@linux.intel.com> Date: Wed, 30 Sep 2009 13:13:59 +0200 Subject: [PATCH] floppy: Add an extra bound check on ioctl arguments
gcc is not convinced that the floppy.c ioctl has sufficient bound checks, and frankly, as a human I have a hard time proving the same more or less (the size comes from the ioctl argument. humpf. maybe. the code isn't very nice)
This patch adds an explicit check to make 100% sure it's safe, better than finding out later that there indeed was a gap.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> --- drivers/block/floppy.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 5c01f74..0f11a77 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -3497,6 +3497,9 @@ static int fd_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))) return -EPERM; + if (size < 0 || size > sizeof(inparam)) + return -EINVAL; + /* copyin */ CLEARSTRUCT(&inparam); if (_IOC_DIR(cmd) & _IOC_WRITE) -- 1.6.2.5
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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