| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <3cc9765c-f32a-fe8a-f7af-fb884ee63b48@amlogic.com>
Date: Fri, 9 Jun 2023 15:59:26 +0800
From: Liang Yang <liang.yang@...ogic.com>
To: Miquel Raynal <miquel.raynal@...tlin.com>
Cc: Arseniy Krasnov <avkrasnov@...rdevices.ru>,
Richard Weinberger <richard@....at>,
Vignesh Raghavendra <vigneshr@...com>,
Neil Armstrong <neil.armstrong@...aro.org>,
Kevin Hilman <khilman@...libre.com>,
Jerome Brunet <jbrunet@...libre.com>,
Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
oxffffaa@...il.com, kernel@...rdevices.ru,
linux-mtd@...ts.infradead.org,
linux-arm-kernel@...ts.infradead.org,
linux-amlogic@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] mtd: rawnand: meson: check buffer length
Hi Miquel,
On 2023/6/8 21:21, Miquel Raynal wrote:
> [ EXTERNAL EMAIL ]
>
> Hi Liang,
>
> liang.yang@...ogic.com wrote on Thu, 8 Jun 2023 20:37:14 +0800:
>
>> Hi Arseniy and Miquel,
>>
>> On 2023/6/8 15:12, Liang Yang wrote:
>>> Hi Miquel,
>>>
>>> On 2023/6/8 14:54, Miquel Raynal wrote:
>>>> [ EXTERNAL EMAIL ]
>>>>
>>>> Hi Liang,
>>>>
>>>> liang.yang@...ogic.com wrote on Thu, 8 Jun 2023 14:42:53 +0800:
>>>>
>>>>> Hi Arseniy,
>>>>>
>>>>> On 2023/6/8 5:17, Arseniy Krasnov wrote:
>>>>>> [ EXTERNAL EMAIL ]
>>>>>>
>>>>>> Hi again Miquel, Liang!
>>>>>>
>>>>>> What do You think about this patch?
>>>>>>
>>>>>> Thanks, Arseniy
>>>>>>
>>>>>> On 06.06.2023 19:29, Arseniy Krasnov wrote:
>>>>>>> Sorry, here is changelog:
>>>>>>> v1 -> v2:
>>>>>>> * Move checks from 'switch/case' which executes commands in >>>>> 'meson_nfc_exec_op()' to a special
>>>>>>> separated function 'meson_nfc_check_op()' which is called >>>>> before commands processing.
>>>>>>>
>>>>>>> On 06.06.2023 13:16, Arseniy Krasnov wrote:
>>>>>>>> Meson NAND controller has limited buffer length, so check it before
>>>>>>>> command execution to avoid length trim. Also check MTD write size on
>>>>>>>> chip attach.
>>>>>>>>
>>>>>>>> Signed-off-by: Arseniy Krasnov <AVKrasnov@...rdevices.ru>
>>>>>>>> ---
>>>>>>>> drivers/mtd/nand/raw/meson_nand.c | 47 >>>>>> +++++++++++++++++++++++++++----
>>>>>>>> 1 file changed, 42 insertions(+), 5 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/mtd/nand/raw/meson_nand.c >>>>>> b/drivers/mtd/nand/raw/meson_nand.c
>>>>>>>> index 23a73268421b..db6b18753071 100644
>>>>>>>> --- a/drivers/mtd/nand/raw/meson_nand.c
>>>>>>>> +++ b/drivers/mtd/nand/raw/meson_nand.c
>>>>>>>> @@ -111,6 +111,8 @@
>>>>>>>>
>>>>>>>> #define PER_INFO_BYTE 8
>>>>>>>>
>>>>>>>> +#define NFC_CMD_RAW_LEN GENMASK(13, 0)
>>>>>>>> +
>>>>>>>> struct meson_nfc_nand_chip {
>>>>>>>> struct list_head node;
>>>>>>>> struct nand_chip nand;
>>>>>>>> @@ -284,7 +286,7 @@ static void meson_nfc_cmd_access(struct >>>>>> nand_chip *nand, int raw, bool dir,
>>>>>>>>
>>>>>>>> if (raw) {
>>>>>>>> len = mtd->writesize + mtd->oobsize;
>>>>>>>> - cmd = (len & GENMASK(13, 0)) | scrambler | DMA_DIR(dir);
>>>>>>>> + cmd = len | scrambler | DMA_DIR(dir);
>>>>>>>> writel(cmd, nfc->reg_base + NFC_REG_CMD);
>>>>>
>>>>> I think we could keep "& GENMASK(13, 0)". it is better here to >>> indicate how many bits of length in this command and don't destory >>> the command once we don't check the "len" outside of this function. >>> or the code "if (len > NFC_CMD_RAW_LEN)" is better to put inside >>> this function nearly. Thanks.
>>>>
>>>> It depends who calls this helper. If only used inside >> exec_op,write_page_raw() and read_page_raw() also call >> meson_nfc_cmd_access(), > but i don't find where constrain the "len".
>>
>> Is the helper "meson_nfc_check_op()" needed by exec_op() after the constraint in attach_chip()? the length passed in exec_op() seems smaller than "mtd->writesize + mtd->oobsize" now.
>
> exec_op() is primarily dedicated to performing side commands than page
> accesses, typically the parameter page is X bytes, you might want to
> read it 3 times, depending on the capabilities of the controller, you
> might need to split the operation or not, so the core checks what are
> the controller capabilities before doing the operation. So yes, the
> check_op() thing is necessary.
ok, i get it. thanks
@Arseniy I have no other questions about this patch.
>
>>
>> @Arseniy if it does need, I think the same constraint is needed by
>> "meson_nfc_cmd_access()"
>>
>>>
>>>> it's not useful. If used outside, then if you want to clarify
>>>> things you may want to use:
>>>>
>>>> #define NFC_CMD_OP_LEN(cmd) FIELD_PREP(GENMASK(13, 0), (cmd))
>>>>
>>>> This is by far my favorite construction. Could apply to many other
>>>> fields, like DMA_DIR, scrambler, etc.
>>
>> @Miquel, FIELD_PREP() is better, but i have no idea whether we should add FIELD_PREP() in this patch, or keep the previous code.
>>
>>>>
>>>>>>>> return;
>>>>>>>> }
>>>>>>>> @@ -573,7 +575,7 @@ static int meson_nfc_read_buf(struct nand_chip >>>>>> *nand, u8 *buf, int len)
>>>>>>>> if (ret)
>>>>>>>> goto out;
>>>>>>>>
>>>>>>>> - cmd = NFC_CMD_N2M | (len & GENMASK(13, 0));
>>>>>>>> + cmd = NFC_CMD_N2M | len;
>>>>>>>> writel(cmd, nfc->reg_base + NFC_REG_CMD);
>>>>>>>>
>>>>>>>> meson_nfc_drain_cmd(nfc);
>>>>>>>> @@ -597,7 +599,7 @@ static int meson_nfc_write_buf(struct >>>>>> nand_chip *nand, u8 *buf, int len)
>>>>>>>> if (ret)
>>>>>>>> return ret;
>>>>>>>>
>>>>>>>> - cmd = NFC_CMD_M2N | (len & GENMASK(13, 0));
>>>>>>>> + cmd = NFC_CMD_M2N | len;
>>>>>>>> writel(cmd, nfc->reg_base + NFC_REG_CMD);
>>>>>>>>
>>>>>>>> meson_nfc_drain_cmd(nfc);
>>>>>>>> @@ -1007,6 +1009,31 @@ meson_nand_op_put_dma_safe_output_buf(const >>>>>> struct nand_op_instr *instr,
>>>>>>>> kfree(buf);
>>>>>>>> }
>>>>>>>>
>>>>>>>> +static int meson_nfc_check_op(struct nand_chip *chip,
>>>>>>>> + const struct nand_operation *op)
>>>>>>>> +{
>>>>>>>> + int op_id;
>>>>>>>> +
>>>>>>>> + for (op_id = 0; op_id < op->ninstrs; op_id++) {
>>>>>>>> + const struct nand_op_instr *instr;
>>>>>>>> +
>>>>>>>> + instr = &op->instrs[op_id];
>>>>>>>> +
>>>>>>>> + switch (instr->type) {
>>>>>>>> + case NAND_OP_DATA_IN_INSTR:
>>>>>>>> + case NAND_OP_DATA_OUT_INSTR:
>>>>>>>> + if (instr->ctx.data.len > NFC_CMD_RAW_LEN)
>>>>>>>> + return -ENOTSUPP;
>>>>>>>> +
>>>>>>>> + break;
>>>>>>>> + default:
>>>>>>>> + break;
>>>>>>>> + }
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> + return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> static int meson_nfc_exec_op(struct nand_chip *nand,
>>>>>>>> const struct nand_operation *op, bool >>>>>> check_only)
>>>>>>>> {
>>>>>>>> @@ -1015,10 +1042,12 @@ static int meson_nfc_exec_op(struct >>>>>> nand_chip *nand,
>>>>>>>> const struct nand_op_instr *instr = NULL;
>>>>>>>> void *buf;
>>>>>>>> u32 op_id, delay_idle, cmd;
>>>>>>>> + int err;
>>>>>>>> int i;
>>>>>>>>
>>>>>>>> - if (check_only)
>>>>>>>> - return 0;
>>>>>>>> + err = meson_nfc_check_op(nand, op);
>>>>>>>> + if (err || check_only)
>>>>>>>> + return err;
>>>>>>>>
>>>>>>>> meson_nfc_select_chip(nand, op->cs);
>>>>>>>> for (op_id = 0; op_id < op->ninstrs; op_id++) {
>>>>>>>> @@ -1293,6 +1322,7 @@ static int meson_nand_attach_chip(struct >>>>>> nand_chip *nand)
>>>>>>>> struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>>>>>>>> struct mtd_info *mtd = nand_to_mtd(nand);
>>>>>>>> int nsectors = mtd->writesize / 1024;
>>>>>>>> + int raw_writesize;
>>>>>>>> int ret;
>>>>>>>>
>>>>>>>> if (!mtd->name) {
>>>>>>>> @@ -1304,6 +1334,13 @@ static int meson_nand_attach_chip(struct >>>>>> nand_chip *nand)
>>>>>>>> return -ENOMEM;
>>>>>>>> }
>>>>>>>>
>>>>>>>> + raw_writesize = mtd->writesize + mtd->oobsize;
>>>>>>>> + if (raw_writesize > NFC_CMD_RAW_LEN) {
>>>>>>>> + dev_err(nfc->dev, "too big write size in raw mode: %d >>>>>> > %ld\n",
>>>>>>>> + raw_writesize, NFC_CMD_RAW_LEN);
>>>>>>>> + return -EINVAL;
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> if (nand->bbt_options & NAND_BBT_USE_FLASH)
>>>>>>>> nand->bbt_options |= NAND_BBT_NO_OOB;
>>>>>>>>
>>>>
>>>>
>>>> Thanks,
>>>> Miquèl
>
>
> Thanks,
> Miquèl
Powered by blists - more mailing lists