From: Michael Walle <michael@walle.cc>
To: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Michael Walle <michael@walle.cc>
Subject: [PATCH] mtd: require write permissions for locking and badblock ioctls
Date: Wed, 3 Mar 2021 16:57:35 +0100 [thread overview]
Message-ID: <20210303155735.25887-1-michael@walle.cc> (raw)
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>
---
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 57c4a2f0b703..30c8273c1eff 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -643,16 +643,12 @@ 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:
@@ -663,9 +659,13 @@ 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;
--
2.20.1
next reply other threads:[~2021-03-03 19:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-03 15:57 Michael Walle [this message]
2021-03-03 16:08 ` [PATCH] mtd: require write permissions for locking and badblock ioctls Greg Kroah-Hartman
2021-03-03 16:17 ` Richard Weinberger
2021-03-03 16:25 ` Michael Walle
2021-03-03 16:34 ` Richard Weinberger
2021-03-22 16:39 ` Rafał Miłecki
2021-03-22 17:54 ` Richard Weinberger
2021-03-28 17:28 ` Miquel Raynal
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