[PATCH] mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op()

Christophe JAILLET christophe.jaillet at wanadoo.fr
Thu Jul 20 11:27:28 PDT 2023


Le 20/07/2023 à 09:04, Dan Carpenter a écrit :
> On Wed, Jul 19, 2023 at 11:55:01PM +0200, Christophe JAILLET wrote:
>> 'op-cs' is copied in 'fun->mchip_number' which is used to access the
>> 'mchip_offsets' and the 'rnb_gpio' arrays.
>> These arrays have NAND_MAX_CHIPS elements, so the index must be below this
>> limit.
>>
>> Fix the sanity check in order to avoid the NAND_MAX_CHIPS value. This
>> would lead to out-of-bound accesses.
>>
>> Fixes: 54309d657767 ("mtd: rawnand: fsl_upm: Implement exec_op()")
>> Signed-off-by: Christophe JAILLET <christophe.jaillet at wanadoo.fr>
>> ---
> 
> Reviewed-by: Dan Carpenter <dan.carpenter at linaro.org>
> 
> Good eye.  I'm assuming you did something like this:
> 
> #!/bin/bash
> 
> FILE=$1
> WORDS=$(cat $FILE | perl -ne 'if ($_ =~ /\[([\w_]+)\];/) { print "$1\n" }' | sort -u)
> for i in $WORDS ; do
>      grep -Hn " > $i" $FILE
> done
> 
> regards,
> dan carpenter
> 

I did with the help of a coccinelle script.
(which can certainly be improved, so adding Julia in cc: :) )

This gives decent results. I only post patches for what I confirm as an 
issue. So it is likely that some good candidates will be left as-is.

So if anyone wants to give it a try, you are welcomed :)

CJ


cocci:
=====
@rule1@
identifier C =~ "[A-Z]+";
expression e;
statement S;
@@
	if (e < C)
		S

@ok1 depends on rule1@
identifier C = rule1.C;
expression e;
statement S;
@@
*	if (e <= C)
		S



@rule2@
identifier C =~ "[A-Z]+";
expression e;
statement S;
@@
	if (e <= C)
		S

@ok2 depends on rule2@
identifier C = rule2.C;
expression e;
statement S;
@@
*	if (e < C)
		S



@rule3@
identifier C =~ "[A-Z]+";
expression e;
statement S;
@@
	if (e > C)
		S

@ok3 depends on rule3@
identifier C = rule3.C;
expression e;
statement S;
@@
*	if (e >= C)
		S



@rule4@
identifier C =~ "[A-Z]+";
expression e;
statement S;
@@
	if (e >= C)
		S

@ok4 depends on rule4@
identifier C = rule4.C;
expression e;
statement S;
@@
*	if (e > C)
		S


CJ



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