From: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
commit 1e020e1b96afdecd20680b5b5be2a6ffc3d27628 upstream.
Following process will make ubi attaching failed since commit
1b42b1a36fc946 ("ubi: ensure that VID header offset ... size"):
ID="0xec,0xa1,0x00,0x15" # 128M 128KB 2KB
modprobe nandsim id_bytes=$ID
flash_eraseall /dev/mtd0
modprobe ubi mtd="0,2048" # set vid_hdr offset as 2048 (one page)
(dmesg):
ubi0 error: ubi_attach_mtd_dev [ubi]: VID header offset 2048 too large.
UBI error: cannot attach mtd0
UBI error: cannot initialize UBI, error -22
Rework original solution, the key point is making sure
'vid_hdr_shift + UBI_VID_HDR_SIZE < ubi->vid_hdr_alsize',
so we should check vid_hdr_shift rather not vid_hdr_offset.
Then, ubi still support (sub)page aligined VID header offset.
Fixes: 1b42b1a36fc946 ("ubi: ensure that VID header offset ... size")
Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Tested-by: Nicolas Schichan <nschichan@xxxxxxxxxx>
Tested-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> # v5.10, v4.19
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mtd/ubi/build.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -665,12 +665,6 @@ static int io_init(struct ubi_device *ub
ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
- if (ubi->vid_hdr_offset && ((ubi->vid_hdr_offset + UBI_VID_HDR_SIZE) >
- ubi->vid_hdr_alsize)) {
- ubi_err(ubi, "VID header offset %d too large.", ubi->vid_hdr_offset);
- return -EINVAL;
- }
-
dbg_gen("min_io_size %d", ubi->min_io_size);
dbg_gen("max_write_size %d", ubi->max_write_size);
dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
@@ -688,6 +682,21 @@ static int io_init(struct ubi_device *ub
ubi->vid_hdr_aloffset;
}
+ /*
+ * Memory allocation for VID header is ubi->vid_hdr_alsize
+ * which is described in comments in io.c.
+ * Make sure VID header shift + UBI_VID_HDR_SIZE not exceeds
+ * ubi->vid_hdr_alsize, so that all vid header operations
+ * won't access memory out of bounds.
+ */
+ if ((ubi->vid_hdr_shift + UBI_VID_HDR_SIZE) > ubi->vid_hdr_alsize) {
+ ubi_err(ubi, "Invalid VID header offset %d, VID header shift(%d)"
+ " + VID header size(%zu) > VID header aligned size(%d).",
+ ubi->vid_hdr_offset, ubi->vid_hdr_shift,
+ UBI_VID_HDR_SIZE, ubi->vid_hdr_alsize);
+ return -EINVAL;
+ }
+
/* Similar for the data offset */
ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
