Commit 8dd765a5 authored by Viresh Kumar's avatar Viresh Kumar Committed by Juergen Gross
Browse files

xen: Make struct privcmd_irqfd's layout architecture independent 



Using indirect pointers in an ioctl command argument means that the
layout is architecture specific, in particular we can't use the same one
from 32-bit compat tasks. The general recommendation is to have __u64
members and use u64_to_user_ptr() to access it from the kernel if we are
unable to avoid the pointers altogether.

Fixes: f8941e6c ("xen: privcmd: Add support for irqfd")
Reported-by: default avatarArnd Bergmann <arnd@kernel.org>
Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmail.com/


Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/a4ef0d4a68fc858b34a81fd3f9877d9b6898eb77.1697439990.git.viresh.kumar@linaro.org


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent d3a2b6b4

drivers/xen/privcmd.c

+1 −1
Original line number Diff line number Diff line
@@ -935,7 +935,7 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) 
		return -ENOMEM;

	dm_op = kirqfd + 1;



	if (copy_from_user(dm_op, irqfd->dm_op, irqfd->size)) {

	if (copy_from_user(dm_op, u64_to_user_ptr(irqfd->dm_op), irqfd->size)) {

		ret = -EFAULT;

		goto error_kfree;

	}

include/uapi/xen/privcmd.h

+1 −1
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ struct privcmd_mmap_resource { 
#define PRIVCMD_IRQFD_FLAG_DEASSIGN (1 << 0)



struct privcmd_irqfd {

	void __user *dm_op;

	__u64 dm_op;

	__u32 size; /* Size of structure pointed by dm_op */

	__u32 fd;

	__u32 flags;