4.9-stable review patch. If anyone has any objections, please let me know.
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From: Romain Izard romain.izard.pro@gmail.com
commit 78a8dfbabbece22bee58ac4cb26cab10e7a19c5d upstream.
When opening a device with write access, ubiblock_open returns an error code. Currently, this error code is -EPERM, but this is not the right value.
The open function for other block devices returns -EROFS when opening read-only devices with FMODE_WRITE set. When used with dm-verity, the veritysetup userspace tool is expecting EROFS, and refuses to use the ubiblock device.
Use -EROFS for ubiblock as well. As a result, veritysetup accepts the ubiblock device as valid.
Cc: stable@vger.kernel.org Fixes: 9d54c8a33eec (UBI: R/O block driver on top of UBI volumes) Signed-off-by: Romain Izard romain.izard.pro@gmail.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mtd/ubi/block.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/mtd/ubi/block.c +++ b/drivers/mtd/ubi/block.c @@ -244,7 +244,7 @@ static int ubiblock_open(struct block_de * in any case. */ if (mode & FMODE_WRITE) { - ret = -EPERM; + ret = -EROFS; goto out_unlock; }