From 4f983ee5e5de924d93a7bbb4e6f68f38c6256cd5 Mon Sep 17 00:00:00 2001 From: Harshit Mogalapalli Date: Fri, 25 Nov 2022 21:07:45 -0800 Subject: [PATCH] xen/privcmd: Fix a possible warning in privcmd_ioctl_mmap_resource() [ Upstream commit 8b997b2bb2c53b76a6db6c195930e9ab8e4b0c79 ] As 'kdata.num' is user-controlled data, if user tries to allocate memory larger than(>=) MAX_ORDER, then kcalloc() will fail, it creates a stack trace and messes up dmesg with a warning. Call trace: -> privcmd_ioctl --> privcmd_ioctl_mmap_resource Add __GFP_NOWARN in order to avoid too large allocation warning. This is detected by static analysis using smatch. Fixes: 3ad0876554ca ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE") Signed-off-by: Harshit Mogalapalli Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/20221126050745.778967-1-harshit.m.mogalapalli@oracle.com Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin --- drivers/xen/privcmd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index d4ff944cd16e1..c4b0de4a542b5 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -766,7 +766,7 @@ static long privcmd_ioctl_mmap_resource(struct file *file, goto out; } - pfns = kcalloc(kdata.num, sizeof(*pfns), GFP_KERNEL); + pfns = kcalloc(kdata.num, sizeof(*pfns), GFP_KERNEL | __GFP_NOWARN); if (!pfns) { rc = -ENOMEM; goto out;