Messages in this thread Patch in this message | | | From | Oleksandr Tyshchenko <> | Subject | Re: [PATCH] xen/privcmd: fix error exit of privcmd_ioctl_dm_op() | Date | Wed, 24 Aug 2022 17:50:43 +0000 |
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On 24.08.22 17:26, Juergen Gross wrote:
Hello Juergen
> The error exit of privcmd_ioctl_dm_op() is calling unlock_pages() > potentially with pages being NULL, leading to a NULL dereference. > > Fix that by calling unlock_pages only if lock_pages() was at least > partially successful. > > Cc: <stable@vger.kernel.org> > Fixes: ab520be8cd5d ("xen/privcmd: Add IOCTL_PRIVCMD_DM_OP") > Reported-by: Rustam Subkhankulov <subkhankulov@ispras.ru> > Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> --- > drivers/xen/privcmd.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c > index 3369734108af..ec87968b4459 100644 > --- a/drivers/xen/privcmd.c > +++ b/drivers/xen/privcmd.c > @@ -679,7 +679,7 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) > rc = lock_pages(kbufs, kdata.num, pages, nr_pages, &pinned); > if (rc < 0) { > nr_pages = pinned; > - goto out; > + goto unlock; > } > > for (i = 0; i < kdata.num; i++) { > @@ -691,8 +691,9 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) > rc = HYPERVISOR_dm_op(kdata.dom, kdata.num, xbufs); > xen_preemptible_hcall_end(); > > -out: > + unlock: > unlock_pages(pages, nr_pages); > + out: > kfree(xbufs); > kfree(pages); > kfree(kbufs);
-- Regards,
Oleksandr Tyshchenko
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