From: Hongling Zeng <zhongling0719@126.com>
To: Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>,
Hongling Zeng <zenghongling@kylinos.cn>,
alexandre.belloni@bootlin.com, Frank.Li@nxp.com,
amergnat@baylibre.com, tze.yee.ng@altera.com,
adrian.ho.yin.ng@altera.com
Cc: linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i3c: fix potential NULL dereference in send_ccc_cmd_locked
Date: Thu, 30 Jul 2026 10:31:50 +0800 [thread overview]
Message-ID: <6A6AB796.1040906@126.com> (raw)
In-Reply-To: <5ac5f386-1b95-4b30-a7e2-c246c9bfad68@oss.qualcomm.com>
在 2026年07月28日 18:27, Mukesh Savaliya 写道:
>
>
> On 7/28/2026 12:00 PM, Hongling Zeng wrote:
>> The retry loop added in commit 02cc832191dd ("i3c: master: Validate GET
>> CCC payload length and retry Direct GET once") resets payload
>> actual_len
>> before each attempt. However, cmd->dests is only validated for DIRECT
>> CCC commands (I3C_CCC_DIRECT bit set). For broadcast commands, dests
>> can be NULL while ndests > 0, causing a NULL pointer dereference at
>> cmd->dests[i].payload.actual_len.
>>
>> Fix by restricting the actual_len reset to DIRECT commands.
>>
>> Fixes: 02cc832191dd ("i3c: master: Validate GET CCC payload length
>> and retry Direct GET once")
>> Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
>> ---
>> drivers/i3c/master.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
>> index fd3e79d10c84..21212c34c31e 100644
>> --- a/drivers/i3c/master.c
>> +++ b/drivers/i3c/master.c
>> @@ -1051,7 +1051,7 @@ static int
>> i3c_master_send_ccc_cmd_locked(struct i3c_master_controller *master,
>> for (attempt = 0; attempt < max_attempts; attempt++) {
>> unsigned int i;
>> - if (cmd->rnw)
>> + if (cmd->rnw && (cmd->id & I3C_CCC_DIRECT))
>
> Please review this recent fix @
> https://lore.kernel.org/all/amJau9LgehYLnR20@lizhi-Precision-Tower-5810/
>
|
|Thanks, Adrian's fix makes more sense by validating the input at the
entry point rather than fixing only the retry loop use site.|
|
>> for (i = 0; i < cmd->ndests; i++)
>> cmd->dests[i].payload.actual_len = 0;
--
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WARNING: multiple messages have this Message-ID (diff)
From: Hongling Zeng <zhongling0719@126.com>
To: Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>,
Hongling Zeng <zenghongling@kylinos.cn>,
alexandre.belloni@bootlin.com, Frank.Li@nxp.com,
amergnat@baylibre.com, tze.yee.ng@altera.com,
adrian.ho.yin.ng@altera.com
Cc: linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i3c: fix potential NULL dereference in send_ccc_cmd_locked
Date: Thu, 30 Jul 2026 10:31:50 +0800 [thread overview]
Message-ID: <6A6AB796.1040906@126.com> (raw)
In-Reply-To: <5ac5f386-1b95-4b30-a7e2-c246c9bfad68@oss.qualcomm.com>
在 2026年07月28日 18:27, Mukesh Savaliya 写道:
>
>
> On 7/28/2026 12:00 PM, Hongling Zeng wrote:
>> The retry loop added in commit 02cc832191dd ("i3c: master: Validate GET
>> CCC payload length and retry Direct GET once") resets payload
>> actual_len
>> before each attempt. However, cmd->dests is only validated for DIRECT
>> CCC commands (I3C_CCC_DIRECT bit set). For broadcast commands, dests
>> can be NULL while ndests > 0, causing a NULL pointer dereference at
>> cmd->dests[i].payload.actual_len.
>>
>> Fix by restricting the actual_len reset to DIRECT commands.
>>
>> Fixes: 02cc832191dd ("i3c: master: Validate GET CCC payload length
>> and retry Direct GET once")
>> Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
>> ---
>> drivers/i3c/master.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
>> index fd3e79d10c84..21212c34c31e 100644
>> --- a/drivers/i3c/master.c
>> +++ b/drivers/i3c/master.c
>> @@ -1051,7 +1051,7 @@ static int
>> i3c_master_send_ccc_cmd_locked(struct i3c_master_controller *master,
>> for (attempt = 0; attempt < max_attempts; attempt++) {
>> unsigned int i;
>> - if (cmd->rnw)
>> + if (cmd->rnw && (cmd->id & I3C_CCC_DIRECT))
>
> Please review this recent fix @
> https://lore.kernel.org/all/amJau9LgehYLnR20@lizhi-Precision-Tower-5810/
>
|
|Thanks, Adrian's fix makes more sense by validating the input at the
entry point rather than fixing only the retry loop use site.|
|
>> for (i = 0; i < cmd->ndests; i++)
>> cmd->dests[i].payload.actual_len = 0;
next prev parent reply other threads:[~2026-07-30 2:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-28 6:30 [PATCH] i3c: fix potential NULL dereference in send_ccc_cmd_locked Hongling Zeng
2026-07-28 6:30 ` Hongling Zeng
2026-07-28 6:46 ` sashiko-bot
2026-07-28 10:27 ` Mukesh Savaliya
2026-07-28 10:27 ` Mukesh Savaliya
2026-07-30 2:31 ` Hongling Zeng [this message]
2026-07-30 2:31 ` Hongling Zeng
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