From: Souptick Joarder jrdr.linux@gmail.com
[ Upstream commit 7f360bec37857bfd5a48cef21d86f58a09a3df63 ]
First, when memory allocation for sg_list_unaligned failed, there is a bug of calling put_pages() as we haven't pinned any pages.
Second, if get_user_pages_fast() failed we should unpin num_pinned pages.
This will address both.
As part of these changes, minor update in documentation.
Fixes: 6db7199407ca ("drivers/virt: introduce Freescale hypervisor management driver") Signed-off-by: Souptick Joarder jrdr.linux@gmail.com Reviewed-by: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: John Hubbard jhubbard@nvidia.com Link: https://lore.kernel.org/r/1598995271-6755-1-git-send-email-jrdr.linux@gmail.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/virt/fsl_hypervisor.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/virt/fsl_hypervisor.c b/drivers/virt/fsl_hypervisor.c index 1b0b11b55d2a0..46ee0a0998b6f 100644 --- a/drivers/virt/fsl_hypervisor.c +++ b/drivers/virt/fsl_hypervisor.c @@ -157,7 +157,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
unsigned int i; long ret = 0; - int num_pinned; /* return value from get_user_pages() */ + int num_pinned = 0; /* return value from get_user_pages_fast() */ phys_addr_t remote_paddr; /* The next address in the remote buffer */ uint32_t count; /* The number of bytes left to copy */
@@ -174,7 +174,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) return -EINVAL;
/* - * The array of pages returned by get_user_pages() covers only + * The array of pages returned by get_user_pages_fast() covers only * page-aligned memory. Since the user buffer is probably not * page-aligned, we need to handle the discrepancy. * @@ -224,7 +224,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p)
/* * 'pages' is an array of struct page pointers that's initialized by - * get_user_pages(). + * get_user_pages_fast(). */ pages = kcalloc(num_pages, sizeof(struct page *), GFP_KERNEL); if (!pages) { @@ -241,7 +241,7 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) if (!sg_list_unaligned) { pr_debug("fsl-hv: could not allocate S/G list\n"); ret = -ENOMEM; - goto exit; + goto free_pages; } sg_list = PTR_ALIGN(sg_list_unaligned, sizeof(struct fh_sg_list));
@@ -250,7 +250,6 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) num_pages, param.source != -1 ? FOLL_WRITE : 0, pages);
if (num_pinned != num_pages) { - /* get_user_pages() failed */ pr_debug("fsl-hv: could not lock source buffer\n"); ret = (num_pinned < 0) ? num_pinned : -EFAULT; goto exit; @@ -292,13 +291,13 @@ static long ioctl_memcpy(struct fsl_hv_ioctl_memcpy __user *p) virt_to_phys(sg_list), num_pages);
exit: - if (pages) { - for (i = 0; i < num_pages; i++) - if (pages[i]) - put_page(pages[i]); + if (pages && (num_pinned > 0)) { + for (i = 0; i < num_pinned; i++) + put_page(pages[i]); }
kfree(sg_list_unaligned); +free_pages: kfree(pages);
if (!ret)