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| author | Michael Walle <michael@walle.cc> | 2021-03-03 16:57:35 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-14 09:50:13 +0200 |
| commit | 7b6552719c0ccbbea29dde4be141da54fdb5877e (patch) | |
| tree | e411ce0f154fc0c7acbcb66d9b36e927a2a3f6d4 | |
| parent | 45eb038029b93877db88297127cd002d0bac940f (diff) | |
| download | linux-stable-7b6552719c0ccbbea29dde4be141da54fdb5877e.tar.gz linux-stable-7b6552719c0ccbbea29dde4be141da54fdb5877e.tar.bz2 linux-stable-7b6552719c0ccbbea29dde4be141da54fdb5877e.zip | |
mtd: require write permissions for locking and badblock ioctls
[ 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>
| -rw-r--r-- | drivers/mtd/mtdchar.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c index b40f46a43fc6..69fb5dafa9ad 100644 --- a/drivers/mtd/mtdchar.c +++ b/drivers/mtd/mtdchar.c @@ -651,16 +651,12 @@ 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: @@ -671,9 +667,13 @@ 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; |