[PATCH] MTD: nandsim: BUG: Fail if overridesize is too big

[PATCH] MTD: nandsim: BUG: Fail if overridesize is too big

[Richard Genoud]

If override size is too big, the module was actually loaded instead of
failing, because retval was not set.

This lead to memory corruption with the use of the freed structs nandsim
and nand_chip.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/mtd/nand/nandsim.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index cf0cd31..5d881180 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -2333,6 +2333,7 @@ static int __init ns_init_module(void)
 		uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
 		if (new_size >> overridesize != nsmtd->erasesize) {
 			NS_ERR("overridesize is too big\n");
+			retval = -EINVAL;
 			goto err_exit;
 		}
 		/* N.B. This relies on nand_scan not doing anything with the size before we change it */
-- 
1.7.2.5

Re: [PATCH] MTD: nandsim: BUG: Fail if overridesize is too big

[Richard Genoud]

2012/9/12 Richard Genoud <richard.genoud@gmail.com>:
> If override size is too big, the module was actually loaded instead of
> failing, because retval was not set.
>
> This lead to memory corruption with the use of the freed structs nandsim
> and nand_chip.
>
> Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
> ---
>  drivers/mtd/nand/nandsim.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
> index cf0cd31..5d881180 100644
> --- a/drivers/mtd/nand/nandsim.c
> +++ b/drivers/mtd/nand/nandsim.c
> @@ -2333,6 +2333,7 @@ static int __init ns_init_module(void)
>                 uint64_t new_size = (uint64_t)nsmtd->erasesize << overridesize;
>                 if (new_size >> overridesize != nsmtd->erasesize) {
>                         NS_ERR("overridesize is too big\n");
> +                       retval = -EINVAL;
>                         goto err_exit;
>                 }
>                 /* N.B. This relies on nand_scan not doing anything with the size before we change it */
> --
> 1.7.2.5
>
Hi Artem, David.

As this is a bug fix, it should be pushed to 3.6-rc7, shouldn't it ?

Regards,
Richard.

Re: [PATCH] MTD: nandsim: BUG: Fail if overridesize is too big

[Artem Bityutskiy]

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On Wed, 2012-09-12 at 14:26 +0200, Richard Genoud wrote:
> If override size is too big, the module was actually loaded instead of
> failing, because retval was not set.
> 
> This lead to memory corruption with the use of the freed structs nandsim
> and nand_chip.
> 
> Signed-off-by: Richard Genoud <richard.genoud@gmail.com>

Pushed to l2-mtd.git, CCed -stable.

-- 
Best Regards,
Artem Bityutskiy

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Re: [PATCH] MTD: nandsim: BUG: Fail if overridesize is too big

[Artem Bityutskiy]

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On Tue, 2012-09-18 at 10:27 +0200, Richard Genoud wrote:
> As this is a bug fix, it should be pushed to 3.6-rc7, shouldn't it ?

Well, it is a fix for an ancient bug, so it is enough to CC the stable
tree and merge this patch normally, I think.

-- 
Best Regards,
Artem Bityutskiy

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