From: Mike Christie <mchristi@redhat.com>
To: Dmitry Fomichev <dmitry.fomichev@wdc.com>,
linux-scsi@vger.kernel.org,
"Martin K . Petersen" <martin.petersen@oracle.com>,
target-devel@vger.kernel.org,
Bart Van Assche <bvanassche@acm.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Subject: Re: [PATCH v2] tcmu: avoid use-after-free after command timeout
Date: Mon, 12 Aug 2019 10:30:19 -0500 [thread overview]
Message-ID: <5D51860B.1060902@redhat.com> (raw)
In-Reply-To: <20190811182510.1706-1-dmitry.fomichev@wdc.com>
On 08/11/2019 01:25 PM, Dmitry Fomichev wrote:
> In tcmu_handle_completion() function, the variable called read_len is
> always initialized with a value taken from se_cmd structure. If this
> function is called to complete an expired (timed out) out command, the
> session command pointed by se_cmd is likely to be already deallocated by
> the target core at that moment. As the result, this access triggers a
> use-after-free warning from KASAN.
>
> This patch fixes the code not to touch se_cmd when completing timed out
> TCMU commands. It also resets the pointer to se_cmd at the time when the
> TCMU_CMD_BIT_EXPIRED flag is set because it is going to become invalid
> after calling target_complete_cmd() later in the same function,
> tcmu_check_expired_cmd().
>
> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
> ---
Acked-by: Mike Christie <mchristi@redhat.com>
next prev parent reply other threads:[~2019-08-12 15:30 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-11 18:25 [PATCH v2] tcmu: avoid use-after-free after command timeout Dmitry Fomichev
2019-08-12 15:30 ` Mike Christie [this message]
2019-08-12 18:00 ` Damien Le Moal
2019-08-15 2:00 ` Martin K. Petersen
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