mtd: parser: cmdline: Fix parsing of part-names with colons

commit 639a82434f16a6df0ce0e7c8595976f1293940fd upstream.

Some devices (especially QCA ones) are already using hardcoded partition
names with colons in it. The OpenMesh A62 for example provides following
mtd relevant information via cmdline:

  root=31:11 mtdparts=spi0.0:256k(0:SBL1),128k(0:MIBIB),384k(0:QSEE),64k(0:CDT),64k(0:DDRPARAMS),64k(0:APPSBLENV),512k(0:APPSBL),64k(0:ART),64k(custom),64k(0:KEYS),0x002b0000(kernel),0x00c80000(rootfs),15552k(inactive) rootfsname=rootfs rootwait

The change to split only on the last colon between mtd-id and partitions
will cause newpart to see following string for the first partition:

  KEYS),0x002b0000(kernel),0x00c80000(rootfs),15552k(inactive)

Such a partition list cannot be parsed and thus the device fails to boot.

Avoid this behavior by making sure that the start of the first part-name
("(") will also be the last byte the mtd-id split algorithm is using for
its colon search.

Fixes: eb13fa022741 ("mtd: parser: cmdline: Support MTD names containing one or more colons")
Cc: stable@vger.kernel.org
Cc: Ron Minnich <rminnich@google.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201124062506.185392-1-sven@narfation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index 04fd845de05fb7cd9af0068b7122b3ac5cfdea46..67b71c476c5b4b323b5ad21b390223d22736b7b4 100644 (file)
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -228,7 +228,7 @@ static int mtdpart_setup_real(char *s)
                struct cmdline_mtd_partition *this_mtd;
                struct mtd_partition *parts;
                int mtd_id_len, num_parts;
-               char *p, *mtd_id, *semicol;
+               char *p, *mtd_id, *semicol, *open_parenth;
 
                /*
                 * Replace the first ';' by a NULL char so strrchr can work
@@ -238,6 +238,14 @@ static int mtdpart_setup_real(char *s)
                if (semicol)
                        *semicol = '\0';
 
+               /*
+                * make sure that part-names with ":" will not be handled as
+                * part of the mtd-id with an ":"
+                */
+               open_parenth = strchr(s, '(');
+               if (open_parenth)
+                       *open_parenth = '\0';
+
                mtd_id = s;
 
                /*
@@ -247,6 +255,10 @@ static int mtdpart_setup_real(char *s)
                 */
                p = strrchr(s, ':');
 
+               /* Restore the '(' now. */
+               if (open_parenth)
+                       *open_parenth = '(';
+
                /* Restore the ';' now. */
                if (semicol)
                        *semicol = ';';