From 1114e3d00f539ecb7a8415663f2a47a80e00a537 Mon Sep 17 00:00:00 2001 From: Simon Kagstrom Date: Tue, 3 Nov 2009 08:08:41 +0200 Subject: [PATCH] mtd: mtdoops: limit the maximum mtd partition size Make the maximum mtdoops partition size to be 8MiB. Indeed, it does not make sense to use anything larger than that anyway. This limit makes it possible to catch stupid mistakes where the user gives e.g., a rootfs partition to mtdoops (which will happily erase it). Signed-off-by: Simon Kagstrom Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/mtdoops.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index 06c538249455..b016eee18657 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -33,6 +33,9 @@ #include #include +/* Maximum MTD partition size */ +#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024) + #define MTDOOPS_KERNMSG_MAGIC 0x5d005d00 #define OOPS_PAGE_SIZE 4096 @@ -310,6 +313,12 @@ static void mtdoops_notify_add(struct mtd_info *mtd) return; } + if (mtd->size > MTDOOPS_MAX_MTD_SIZE) { + printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n", + mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024); + return; + } + /* oops_page_used is a bit field */ cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages, BITS_PER_LONG)); @@ -317,14 +326,10 @@ static void mtdoops_notify_add(struct mtd_info *mtd) printk(KERN_ERR "Could not allocate page array\n"); return; } - cxt->mtd = mtd; - if (mtd->size > INT_MAX) - cxt->oops_pages = INT_MAX / OOPS_PAGE_SIZE; - else - cxt->oops_pages = (int)mtd->size / OOPS_PAGE_SIZE; + cxt->mtd = mtd; + cxt->oops_pages = (int)mtd->size / OOPS_PAGE_SIZE; find_next_position(cxt); - printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index); } -- GitLab