[PATCH v2 1/2] Fix corner case in bad block table handling.

From: Yoshio Furuyama
Date: Mon Apr 05 2021 - 22:07:19 EST


From: "Doyle, Patrick" <pdoyle@xxxxxxxxxx>

In the unlikely event that both blocks 10 and 11 are marked as bad (on a
32 bit machine), then the process of marking block 10 as bad stomps on
cached entry for block 11. There are (of course) other examples.

Signed-off-by: Patrick Doyle <pdoyle@xxxxxxxxxx>
Reviewed-by: Richard Weinberger <richard@xxxxxx>
---
drivers/mtd/nand/bbt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/bbt.c b/drivers/mtd/nand/bbt.c
index 044adf913854..64af6898131d 100644
--- a/drivers/mtd/nand/bbt.c
+++ b/drivers/mtd/nand/bbt.c
@@ -123,7 +123,7 @@ int nanddev_bbt_set_block_status(struct nand_device *nand, unsigned int entry,
unsigned int rbits = bits_per_block + offs - BITS_PER_LONG;

pos[1] &= ~GENMASK(rbits - 1, 0);
- pos[1] |= val >> rbits;
+ pos[1] |= val >> (bits_per_block - rbits);
}

return 0;
--
2.25.1