diff options
| author | Dan Carpenter <[email protected]> | 2019-05-14 15:47:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2019-05-14 19:52:52 -0700 |
| commit | 6a024330650e24556b8a18cc654ad00cfecf6c6c (patch) | |
| tree | eba90968fd5b597b489649def7ad4a6d0d0e5aeb | |
| parent | c8ea3663f7a8e6996d44500ee818c9330ac4fd88 (diff) | |
drivers/virt/fsl_hypervisor.c: prevent integer overflow in ioctl
The "param.count" value is a u64 thatcomes from the user. The code
later in the function assumes that param.count is at least one and if
it's not then it leads to an Oops when we dereference the ZERO_SIZE_PTR.
Also the addition can have an integer overflow which would lead us to
allocate a smaller "pages" array than required. I can't immediately
tell what the possible run times implications are, but it's safest to
prevent the overflow.
Link: http://lkml.kernel.org/r/20181218082129.GE32567@kadam
Fixes: 6db7199407ca ("drivers/virt: introduce Freescale hypervisor management driver")
Signed-off-by: Dan Carpenter <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Cc: Timur Tabi <[email protected]>
Cc: Mihai Caraman <[email protected]>
Cc: Kumar Gala <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | drivers/virt/fsl_hypervisor.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c index a41431edbf25..93d5bebf9572 100644 --- a/drivers/virt/fsl_hypervisor.c +++ b/drivers/virt/fsl_hypervisor.c @@ -215,6 +215,9 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) * hypervisor. */ lb_offset = param.local_vaddr & (PAGE_SIZE - 1); + if (param.count == 0 || + param.count > U64_MAX - lb_offset - PAGE_SIZE + 1) + return -EINVAL; num_pages = (param.count + lb_offset + PAGE_SIZE - 1) >> PAGE_SHIFT; /* Allocate the buffers we need */ |