This is a note to let you know that I've just added the patch titled ubi: Fix failure attaching when vid_hdr offset equals to (sub)page size to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ubi-fix-failure-attaching-when-vid_hdr-offset-equals-to-sub-page-size.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 1e020e1b96afdecd20680b5b5be2a6ffc3d27628 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> Date: Mon, 6 Mar 2023 09:33:08 +0800 Subject: ubi: Fix failure attaching when vid_hdr offset equals to (sub)page size 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 @@ -648,12 +648,6 @@ 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); @@ -671,6 +665,21 @@ 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); Patches currently in stable-queue which might be from chengzhihao1@xxxxxxxxxx are queue-4.14/ubi-fix-failure-attaching-when-vid_hdr-offset-equals-to-sub-page-size.patch