From: Oscar Carter oscar.carter@gmx.com
commit 769acc3656d93aaacada814939743361d284fd87 upstream.
Check the return value of gasket_get_bar_index function as it can return a negative one (-EINVAL). If this happens, a negative index is used in the "gasket_dev->bar_data" array.
Addresses-Coverity-ID: 1438542 ("Negative array index read") Fixes: 9a69f5087ccc2 ("drivers/staging: Gasket driver framework + Apex driver") Signed-off-by: Oscar Carter oscar.carter@gmx.com Cc: stable stable@vger.kernel.org Reviewed-by: Richard Yeh rcy@google.com Link: https://lore.kernel.org/r/20200501155118.13380-1-oscar.carter@gmx.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/staging/gasket/gasket_core.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/staging/gasket/gasket_core.c +++ b/drivers/staging/gasket/gasket_core.c @@ -933,6 +933,10 @@ do_map_region(const struct gasket_dev *g gasket_get_bar_index(gasket_dev, (vma->vm_pgoff << PAGE_SHIFT) + driver_desc->legacy_mmap_address_offset); + + if (bar_index < 0) + return DO_MAP_REGION_INVALID; + phys_base = gasket_dev->bar_data[bar_index].phys_base + phys_offset; while (mapped_bytes < map_length) { /*