From: Michael Walle <michael@walle.cc> [ Upstream commit 1e97743fd180981bef5f01402342bb54bf1c6366 ] MEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require write permission. Depending on the hardware MEMLOCK might even be write-once, e.g. for SPI-NOR flashes with their WP# tied to GND. OTPLOCK is always write-once. MEMSETBADBLOCK modifies the bad block table. Fixes: f7e6b19bc764 ("mtd: properly check all write ioctls for permissions") Signed-off-by: Michael Walle <michael@walle.cc> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Rafał Miłecki <rafal@milecki.pl> Acked-by: Richard Weinberger <richard@nod.at> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20210303155735.25887-1-michael@walle.cc Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/mtd/mtdchar.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index 5afc653c09e20..82d38001d5175 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -663,16 +663,12 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) case MEMGETINFO: case MEMREADOOB: case MEMREADOOB64: - case MEMLOCK: - case MEMUNLOCK: case MEMISLOCKED: case MEMGETOOBSEL: case MEMGETBADBLOCK: - case MEMSETBADBLOCK: case OTPSELECT: case OTPGETREGIONCOUNT: case OTPGETREGIONINFO: - case OTPLOCK: case ECCGETLAYOUT: case ECCGETSTATS: case MTDFILEMODE: @@ -683,9 +679,13 @@ static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg) /* "dangerous" commands */ case MEMERASE: case MEMERASE64: + case MEMLOCK: + case MEMUNLOCK: + case MEMSETBADBLOCK: case MEMWRITEOOB: case MEMWRITEOOB64: case MEMWRITE: + case OTPLOCK: if (!(file->f_mode & FMODE_WRITE)) return -EPERM; break; -- 2.25.1