2021-09-03 11:38:22

by Evgeny Novikov

Subject: [PATCH] mtd: rawnand: intel: Fix potential buffer overflow in probe

ebu_nand_probe() read the value of u32 variable "cs" from the device
firmware description and used it as the index for array ebu_host->cs
that can contain MAX_CS (2) elements at most. That could result in
a buffer overflow and various bad consequences later.

Fix the potential buffer overflow by restricting values of "cs" with
MAX_CS in probe.

Found by Linux Driver Verification project (linuxtesting.org).

Fixes: 0b1039f016e8 ("mtd: rawnand: Add NAND controller support on Intel LGM SoC")
Signed-off-by: Evgeny Novikov <[email protected]>
Co-developed-by: Kirill Shilimanov <[email protected]>
Signed-off-by: Kirill Shilimanov <[email protected]>
Co-developed-by: Anton Vasilyev <[email protected]>
Signed-off-by: Anton Vasilyev <[email protected]>
---
drivers/mtd/nand/raw/intel-nand-controller.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/nand/raw/intel-nand-controller.c b/drivers/mtd/nand/raw/intel-nand-controller.c
index 8b49fd56cf96..81678088fdca 100644
--- a/drivers/mtd/nand/raw/intel-nand-controller.c
+++ b/drivers/mtd/nand/raw/intel-nand-controller.c
@@ -609,6 +609,11 @@ static int ebu_nand_probe(struct platform_device *pdev)
dev_err(dev, "failed to get chip select: %d\n", ret);
return ret;
}
+ if (cs >= MAX_CS) {
+ dev_err(dev, "got invalid chip select: %d\n", cs);
+ return -EINVAL;
+ }
+
ebu_host->cs_num = cs;

resname = devm_kasprintf(dev, GFP_KERNEL, "nand_cs%d", cs);
--
2.26.2

2021-09-14 17:41:29

by Miquel Raynal

Subject: Re: [PATCH] mtd: rawnand: intel: Fix potential buffer overflow in probe

On Fri, 2021-09-03 at 08:26:53 UTC, Evgeny Novikov wrote:
> ebu_nand_probe() read the value of u32 variable "cs" from the device
> firmware description and used it as the index for array ebu_host->cs
> that can contain MAX_CS (2) elements at most. That could result in
> a buffer overflow and various bad consequences later.
>
> Fix the potential buffer overflow by restricting values of "cs" with
> MAX_CS in probe.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Fixes: 0b1039f016e8 ("mtd: rawnand: Add NAND controller support on Intel LGM SoC")
> Signed-off-by: Evgeny Novikov <[email protected]>
> Co-developed-by: Kirill Shilimanov <[email protected]>
> Signed-off-by: Kirill Shilimanov <[email protected]>
> Co-developed-by: Anton Vasilyev <[email protected]>
> Signed-off-by: Anton Vasilyev <[email protected]>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel