From: Jordy Zomer <jordy@pwning.systems> stable inclusion from stable-v5.10.99 commit 5d40f1bdad3dd1a177f21a90ad4353c1ed40ba3a bugzilla: https://gitee.com/openeuler/kernel/issues/I55O7H Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 92c4cfaee6872038563c5b6f2e8e613f9d84d47d upstream. It appears like nr could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer <jordy@pwning.systems> Fixes: c02a81fba74f ("dma-buf: Add dma-buf heaps framework") Cc: <stable@vger.kernel.org> # v5.6+ Acked-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> [sumits: added fixes and cc: stable tags] Link: https://patchwork.freedesktop.org/patch/msgid/20220129150604.3461652-1-jordy... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/dma-buf/dma-heap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index afd22c9dbdcf..798f86fcd50f 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -14,6 +14,7 @@ #include <linux/xarray.h> #include <linux/list.h> #include <linux/slab.h> +#include <linux/nospec.h> #include <linux/uaccess.h> #include <linux/syscalls.h> #include <linux/dma-heap.h> @@ -123,6 +124,7 @@ static long dma_heap_ioctl(struct file *file, unsigned int ucmd, if (nr >= ARRAY_SIZE(dma_heap_ioctl_cmds)) return -EINVAL; + nr = array_index_nospec(nr, ARRAY_SIZE(dma_heap_ioctl_cmds)); /* Get the kernel ioctl cmd that matches */ kcmd = dma_heap_ioctl_cmds[nr]; -- 2.20.1