From: Harshit Mogalapalli harshit.m.mogalapalli@oracle.com
[ 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 harshit.m.mogalapalli@oracle.com Reviewed-by: Juergen Gross jgross@suse.com Link: https://lore.kernel.org/r/20221126050745.778967-1-harshit.m.mogalapalli@orac... Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 d4ff944cd16e..c4b0de4a542b 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;