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Subject: Re: [PATCH] ubi: eba: properly rollback inside self_check_eba
To: Fedor Pchelkin <pchelkin@ispras.ru>, Richard Weinberger <richard@nod.at>
CC: Miquel Raynal <miquel.raynal@bootlin.com>, Vignesh Raghavendra
	<vigneshr@ti.com>, Artem Bityutskiy <artem.bityutskiy@linux.intel.com>,
	<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>, Alexey
 Khoroshilov <khoroshilov@ispras.ru>, <lvc-project@linuxtesting.org>,
	<stable@vger.kernel.org>
References: <20240229204237.30453-1-pchelkin@ispras.ru>
From: Zhihao Cheng <chengzhihao1@huawei.com>
Message-ID: <1421503e-b1d2-87f2-e33e-1a0428100be2@huawei.com>
Date: Fri, 1 Mar 2024 09:23:58 +0800
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?? 2024/3/1 4:42, Fedor Pchelkin д??:
> In case of a memory allocation failure in the volumes loop we can only
> process the already allocated scan_eba and fm_eba array elements on the
> error path - others are still uninitialized.
> 
> Found by Linux Verification Center (linuxtesting.org).
> 
> Fixes: 00abf3041590 ("UBI: Add self_check_eba()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
> ---
>   drivers/mtd/ubi/eba.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
> 
> diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
> index 8d1f0e05892c..6f5eadb1598d 100644
> --- a/drivers/mtd/ubi/eba.c
> +++ b/drivers/mtd/ubi/eba.c
> @@ -1557,6 +1557,7 @@ int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
>   					  GFP_KERNEL);
>   		if (!fm_eba[i]) {
>   			ret = -ENOMEM;
> +			kfree(scan_eba[i]);
>   			goto out_free;
>   		}
>   
> @@ -1592,7 +1593,7 @@ int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
>   	}
>   
>   out_free:
> -	for (i = 0; i < num_volumes; i++) {
> +	while (--i >= 0) {
>   		if (!ubi->volumes[i])
>   			continue;
>   
>