Messages in this thread Patch in this message | | | Subject | [PATCH v2] comedi: integer overflow in do_insnlist_ioctl() | From | Xi Wang <> | Date | Wed, 23 Nov 2011 11:53:01 -0500 |
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There is a potential integer overflow in do_insnlist_ioctl() if userspace passes in a large insnlist.n_insns. The call to kmalloc() would allocate a small buffer, leading to a memory corruption.
Reported-by: Haogang Chen <haogangchen@gmail.com> Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Suggested-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Xi Wang <xi.wang@gmail.com> --- drivers/staging/comedi/comedi_fops.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 21d8c1c..df86a9e 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -670,8 +670,9 @@ static int do_insnlist_ioctl(struct comedi_device *dev, goto error; } - insns = - kmalloc(sizeof(struct comedi_insn) * insnlist.n_insns, GFP_KERNEL); + if (insnlist.n_insns <= ULONG_MAX / sizeof(struct comedi_insn)) + insns = kmalloc(sizeof(struct comedi_insn) * insnlist.n_insns, + GFP_KERNEL); if (!insns) { DPRINTK("kmalloc failed\n"); ret = -ENOMEM; -- 1.7.5.4
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