From 3716b5e4e6374883c80e61021923733b14cdb011 Mon Sep 17 00:00:00 2001 From: Mathias Kresin Date: Sun, 8 Jul 2018 23:18:15 +0200 Subject: [PATCH] kernel: don't auto attach ubi on read error With a10a204aab26cc ("kernel: make ubi auto-attach check for a tar file magic") the check for the magic was added without considering a failing mtd_read(). If the read fails, no check is done and the mount code is called straight away. Failing with an error message for such cases seems to me the cleaner way, as it would allow to spot hidden/workaround issues. Signed-off-by: Mathias Kresin --- ...ach-mtd-device-named-ubi-or-data-on-boot.patch | 15 ++++++++++----- ...ach-mtd-device-named-ubi-or-data-on-boot.patch | 15 ++++++++++----- 2 files changed, 20 insertions(+), 10 deletions(-) diff --git a/target/linux/generic/pending-4.14/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch b/target/linux/generic/pending-4.14/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch index 66da310e84b6..6e4dd3b36097 100644 --- a/target/linux/generic/pending-4.14/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch +++ b/target/linux/generic/pending-4.14/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch @@ -8,7 +8,7 @@ Signed-off-by: Daniel Golle --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c -@@ -1171,6 +1171,68 @@ static struct mtd_info * __init open_mtd +@@ -1171,6 +1171,73 @@ static struct mtd_info * __init open_mtd return mtd; } @@ -44,10 +44,15 @@ Signed-off-by: Daniel Golle + } + } + -+ /* check for a valid ubi magic if read from flash was successful */ ++ /* check if the read from flash was successful */ + err = mtd_read(mtd, offset, 4, &len, (void *) magic); -+ if ((!err || mtd_is_bitflip(err)) && -+ len == 4 && strncmp(magic, "UBI#", 4)) { ++ if ((err && !mtd_is_bitflip(err)) || len != 4) { ++ pr_err("UBI error: unable to read from mtd%d\n", mtd->index); ++ goto cleanup; ++ } ++ ++ /* check for a valid ubi magic */ ++ if (strncmp(magic, "UBI#", 4)) { + pr_err("UBI error: no valid UBI magic found inside mtd%d\n", mtd->index); + goto cleanup; + } @@ -77,7 +82,7 @@ Signed-off-by: Daniel Golle static int __init ubi_init(void) { int err, i, k; -@@ -1254,6 +1316,12 @@ static int __init ubi_init(void) +@@ -1254,6 +1321,12 @@ static int __init ubi_init(void) } } diff --git a/target/linux/generic/pending-4.9/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch b/target/linux/generic/pending-4.9/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch index 8b923d17d634..168cfe50ee42 100644 --- a/target/linux/generic/pending-4.9/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch +++ b/target/linux/generic/pending-4.9/490-ubi-auto-attach-mtd-device-named-ubi-or-data-on-boot.patch @@ -8,7 +8,7 @@ Signed-off-by: Daniel Golle --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c -@@ -1226,6 +1226,68 @@ static struct mtd_info * __init open_mtd +@@ -1226,6 +1226,73 @@ static struct mtd_info * __init open_mtd return mtd; } @@ -44,10 +44,15 @@ Signed-off-by: Daniel Golle + } + } + -+ /* check for a valid ubi magic if read from flash was successful */ ++ /* check if the read from flash was successful */ + err = mtd_read(mtd, offset, 4, &len, (void *) magic); -+ if ((!err || mtd_is_bitflip(err)) && -+ len == 4 && strncmp(magic, "UBI#", 4)) { ++ if ((err && !mtd_is_bitflip(err)) || len != 4) { ++ pr_err("UBI error: unable to read from mtd%d\n", mtd->index); ++ goto cleanup; ++ } ++ ++ /* check for a valid ubi magic */ ++ if (strncmp(magic, "UBI#", 4)) { + pr_err("UBI error: no valid UBI magic found inside mtd%d\n", mtd->index); + goto cleanup; + } @@ -77,7 +82,7 @@ Signed-off-by: Daniel Golle static int __init ubi_init(void) { int err, i, k; -@@ -1309,6 +1371,12 @@ static int __init ubi_init(void) +@@ -1309,6 +1376,12 @@ static int __init ubi_init(void) } } -- 2.30.2