From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: Kunwu Chan <chentao@kylinos.cn>
Cc: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com,
rodrigo.vivi@intel.com, tvrtko.ursulin@linux.intel.com,
airlied@gmail.com, daniel@ffwll.ch,
intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, kunwu.chan@hotmail.com
Subject: Re: [PATCH] drm/i915/display: Fix null pointer dereference in intel_dp_aux_wait_done and intel_dp_aux_xfer
Date: Thu, 23 Nov 2023 14:23:16 +0200 [thread overview]
Message-ID: <ZV9ENJIVKztrI2gs@intel.com> (raw)
In-Reply-To: <20231123100431.34453-1-chentao@kylinos.cn>
On Thu, Nov 23, 2023 at 06:04:31PM +0800, Kunwu Chan wrote:
> kasprintf() returns a pointer to dynamically allocated memory
> which can be NULL upon failure. When "intel_dp->aux.name" is NULL,
> these error messages will trigger the null pointer dereference issue.
How did you reach that conclusion?
>
> Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
> ---
> drivers/gpu/drm/i915/display/intel_dp_aux.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> index 2e2af71bcd5a..398c9064eb09 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> @@ -67,7 +67,7 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp)
> if (ret == -ETIMEDOUT)
> drm_err(&i915->drm,
> "%s: did not complete or timeout within %ums (status 0x%08x)\n",
> - intel_dp->aux.name, timeout_ms, status);
> + intel_dp->aux.name ? intel_dp->aux.name : "", timeout_ms, status);
>
> return status;
> }
> @@ -302,7 +302,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> if (status != intel_dp->aux_busy_last_status) {
> drm_WARN(&i915->drm, 1,
> "%s: not started (status 0x%08x)\n",
> - intel_dp->aux.name, status);
> + intel_dp->aux.name ? intel_dp->aux.name : "", status);
> intel_dp->aux_busy_last_status = status;
> }
>
> @@ -362,7 +362,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
>
> if ((status & DP_AUX_CH_CTL_DONE) == 0) {
> drm_err(&i915->drm, "%s: not done (status 0x%08x)\n",
> - intel_dp->aux.name, status);
> + intel_dp->aux.name ? intel_dp->aux.name : "", status);
> ret = -EBUSY;
> goto out;
> }
> @@ -374,7 +374,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> */
> if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
> drm_err(&i915->drm, "%s: receive error (status 0x%08x)\n",
> - intel_dp->aux.name, status);
> + intel_dp->aux.name ? intel_dp->aux.name : "", status);
> ret = -EIO;
> goto out;
> }
> @@ -385,7 +385,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> */
> if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
> drm_dbg_kms(&i915->drm, "%s: timeout (status 0x%08x)\n",
> - intel_dp->aux.name, status);
> + intel_dp->aux.name ? intel_dp->aux.name : "", status);
> ret = -ETIMEDOUT;
> goto out;
> }
> @@ -401,7 +401,7 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> if (recv_bytes == 0 || recv_bytes > 20) {
> drm_dbg_kms(&i915->drm,
> "%s: Forbidden recv_bytes = %d on aux transaction\n",
> - intel_dp->aux.name, recv_bytes);
> + intel_dp->aux.name ? intel_dp->aux.name : "", recv_bytes);
> ret = -EBUSY;
> goto out;
> }
> --
> 2.34.1
--
Ville Syrjälä
Intel
prev parent reply other threads:[~2023-11-23 12:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-23 10:04 [PATCH] drm/i915/display: Fix null pointer dereference in intel_dp_aux_wait_done and intel_dp_aux_xfer Kunwu Chan
2023-11-23 12:23 ` Ville Syrjälä [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZV9ENJIVKztrI2gs@intel.com \
--to=ville.syrjala@linux.intel.com \
--cc=airlied@gmail.com \
--cc=chentao@kylinos.cn \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=intel-gfx@lists.freedesktop.org \
--cc=jani.nikula@linux.intel.com \
--cc=joonas.lahtinen@linux.intel.com \
--cc=kunwu.chan@hotmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rodrigo.vivi@intel.com \
--cc=tvrtko.ursulin@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox