6.6-stable review patch. If anyone has any objections, please let me know.
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From: Mikhail Arkhipov m.arhipov@rosa.ru
[ Upstream commit d95846350aac72303036a70c4cdc69ae314aa26d ]
If ctx->steps is zero, the loop processing ECC steps is skipped, and the variable ret remains uninitialized. It is later checked and returned, which leads to undefined behavior and may cause unpredictable results in user space or kernel crashes.
This scenario can be triggered in edge cases such as misconfigured geometry, ECC engine misuse, or if ctx->steps is not validated after initialization.
Initialize ret to zero before the loop to ensure correct and safe behavior regardless of the ctx->steps value.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 48e6633a9fa2 ("mtd: nand: mxic-ecc: Add Macronix external ECC engine support") Signed-off-by: Mikhail Arkhipov m.arhipov@rosa.ru Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mtd/nand/ecc-mxic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mtd/nand/ecc-mxic.c b/drivers/mtd/nand/ecc-mxic.c index 47e10945b8d27..63cb206269dd9 100644 --- a/drivers/mtd/nand/ecc-mxic.c +++ b/drivers/mtd/nand/ecc-mxic.c @@ -614,7 +614,7 @@ static int mxic_ecc_finish_io_req_external(struct nand_device *nand, { struct mxic_ecc_engine *mxic = nand_to_mxic(nand); struct mxic_ecc_ctx *ctx = nand_to_ecc_ctx(nand); - int nents, step, ret; + int nents, step, ret = 0;
if (req->mode == MTD_OPS_RAW) return 0;