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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2019-04-26 10:55:02 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2019-04-30 20:00:27 +1000 |
| commit | 487d8fbb3193781e6a9276b8509a09365f644f02 (patch) | |
| tree | cf41400b74abf23d85c6dc5d4dc504d9d6c4e8c7 | |
| parent | db783a4c3842847c0f921cc2d97d12255b7efd43 (diff) | |
| download | linux-487d8fbb3193781e6a9276b8509a09365f644f02.tar.gz linux-487d8fbb3193781e6a9276b8509a09365f644f02.tar.xz | |
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 <dan.carpenter@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Timur Tabi <timur@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
| -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 */ |