This is a note to let you know that I've just added the patch titled xen/privcmd: Fix a possible warning in privcmd_ioctl_mmap_resource() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xen-privcmd-fix-a-possible-warning-in-privcmd_ioctl_.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1803bac9cffc431e383fd0ad0a268aaff5d95f25 Author: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx> Date: Fri Nov 25 21:07:45 2022 -0800 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 <harshit.m.mogalapalli@xxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Link: https://lore.kernel.org/r/20221126050745.778967-1-harshit.m.mogalapalli@xxxxxxxxxx Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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;