4.19-stable review patch. If anyone has any objections, please let me know.
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From: Zhihao Cheng chengzhihao1@huawei.com
[ Upstream commit 017c73a34a661a861712f7cc1393a123e5b2208c ]
There exists mtd devices with zero erasesize, which will trigger a divide-by-zero exception while attaching ubi device. Fix it by refusing attaching if mtd's erasesize is 0.
Fixes: 801c135ce73d ("UBI: Unsorted Block Images") Reported-by: Yu Hao yhao016@ucr.edu Link: https://lore.kernel.org/lkml/977347543.226888.1682011999468.JavaMail.zimbra@... Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Richard Weinberger richard@nod.at Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/ubi/build.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 3eb14c68cb9b2..3e7e5b51eafd0 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -878,6 +878,13 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, return -EINVAL; }
+ /* UBI cannot work on flashes with zero erasesize. */ + if (!mtd->erasesize) { + pr_err("ubi: refuse attaching mtd%d - zero erasesize flash is not supported\n", + mtd->index); + return -EINVAL; + } + if (ubi_num == UBI_DEV_NUM_AUTO) { /* Search for an empty slot in the @ubi_devices array */ for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)