On Wednesday, March 4, 2020 6:06:46 PM CET Domenico Andreoli wrote:
> From: Domenico Andreoli <domenico.andreoli@xxxxxxxxx>
>
> It turns out that there is one use case for programs being able to
> write to swap devices, and that is the userspace hibernation code.
>
> Quick fix: disable the S_SWAPFILE check if hibernation is configured.
>
> Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files")
> Reported-by: Domenico Andreoli <domenico.andreoli@xxxxxxxxx>
> Reported-by: Marian Klein <mkleinsoft@xxxxxxxxx>
> Signed-off-by: Domenico Andreoli <domenico.andreoli@xxxxxxxxx>
>
> v2:
> - use hibernation_available() instead of IS_ENABLED(CONFIG_HIBERNATE)
> - make Fixes: point to the right commit
This looks OK to me.
Has it been taken care of already, or am I expected to apply it?
> ---
> fs/block_dev.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> Index: b/fs/block_dev.c
> ===================================================================
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -34,6 +34,7 @@
> #include <linux/task_io_accounting_ops.h>
> #include <linux/falloc.h>
> #include <linux/uaccess.h>
> +#include <linux/suspend.h>
> #include "internal.h"
>
> struct bdev_inode {
> @@ -2001,7 +2002,8 @@ ssize_t blkdev_write_iter(struct kiocb *
> if (bdev_read_only(I_BDEV(bd_inode)))
> return -EPERM;
>
> - if (IS_SWAPFILE(bd_inode))
> + /* uswsusp needs write permission to the swap */
> + if (IS_SWAPFILE(bd_inode) && !hibernation_available())
> return -ETXTBSY;
>
> if (!iov_iter_count(from))
>
