From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792676397; b=3UCCze2VKuliCviUggexqpEDO6OfSCqrILF3JZm5BCCL7lvrp1Tu8c52V3Suj6GzpULS cSxYidSvWZkWQWbAUt9QDz9SSHPkoWi3r1UCLtbzlMK7xpmbdLydSz5S2ScOv8y5eqp49 vitiSFQnYMsJ26zwNWh3892x3tzSyxg3gCdSANysEohuxfdYxrmsZLD8ozfVfNXFM1mwa 5Fg7Iiw1k8VfN8J91d/sBtSxmy5hc6Jf8KBkHrklpbXhCg+0Kw5fq47MIwgrE+JmC0Y1U E5CdiZI8ye1jWLaKh1PWGslvtTo8fMLmrR3nLfCAGxCLL9RnZrg8/W7njZlc55r6FUg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792676397; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=ckfGmlxk/j360Pa+hHTBheMqJ6vtsGxDjfVuFGw7y1Q=; b=dC83UzGbWD3oCbqnHEeJNX+3BlGdJZ6gAMFH2Y4OzvUESiYzkaq4jlIrZHFlHT0g+GAx xlwCmdrMwdPgrHY12IGJH4TQ0ugCc18bn0nse2ba4BCfL9adQwCxgoFGkaND9X8JwQU0B KUyW2o9S/Bst21BWB49uXsX56+6XxXA3xC2IrkMy/Uq+AWILMwpyG0USTDs2wwaYk44Dc qMJsf2XlVy8v6SVxyjSJ6ivBHquM+0KG0aTXdzsVtuekjzU4OakSW698G9gmVWKq2cZoK 9G/nli4wfacnj1DOB+ig7kd1+nzq8IayLyMLLOeZ4nsZsgLzXn3qbXvQ0pblUayqiTg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Ycr5FYO2; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DC0AF606A31D for ; Thu, 22 Oct 2026 13:39:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Ycr5FYO2 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D1EF1F000C3; Thu, 22 Oct 2026 13:39:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792676396; bh=ckfGmlxk/j360Pa+hHTBheMqJ6vtsGxDjfVuFGw7y1Q=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Ycr5FYO2RNEts4SPKekdNpG08NA82ErdDNVdmjHhyhCrMaT9CmcanEnEnAjfugFtv 6+bWux3VUkAioWt6zowgykntxWAu9sJ10+oEgIPQsZdP2UAerd9KH+8N89ohT4q45c XIK8Yd6fNsau+ANIAWFM0R/dLRiZopy7yo26BYImLaFHOAOPI7t75J7WJIkLXnwKtF lfR62qY0XKumQ4tQGxJWd48zX8OuRwx1iQgrpklZYrPpJTfDZ59uYsbVRsTyZmlKiV d8QgNPvQHiIJnpEZbwrO0yaZl0ZqHbsAuPX0TN2jkR00k1fRgcZCNlp0HXFFE1v/Mw 4BPQBp91wpI7g== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 2/7] drm/panel: Add Hitachi TX10D07VM0BAA MIPI DBI Type B panel driver Reply-To: sashiko-reviews@lists.linux.dev To: "Svyatoslav Ryhel" Cc: dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, robh@kernel.org, conor+dt@kernel.org In-Reply-To: <20261022132259.240717-3-clamor95@gmail.com> References: <20261022132259.240717-1-clamor95@gmail.com> <20261022132259.240717-3-clamor95@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 22 Oct 2026 13:39:55 +0000 X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] drm/panel: hitachi-tx10d07vm0baa: NULL deref of priv->dbi in enabl= e/disable -- commit 918fbda401f49537dce4afff189990897a904ac4 Author: Svyatoslav Ryhel drm/panel: Add Hitachi TX10D07VM0BAA MIPI DBI Type B panel driver This commit adds a DRM panel driver for the Hitachi TX10D07VM0BAA 4" WVGA MIPI DBI Type B panel used in the LG Optimus 2X P990 smartphone. > diff --git a/drivers/gpu/drm/panel/panel-hitachi-tx10d07vm0baa.c b/driver= s/gpu/drm/panel/panel-hitachi-tx10d07vm0baa.c > new file mode 100644 > index 0000000000000..83c2af1be9755 > --- /dev/null > +++ b/drivers/gpu/drm/panel/panel-hitachi-tx10d07vm0baa.c > @@ -0,0 +1,297 @@ [ ... ] > +#define panel_dbi_command(priv, cmd, seq...) \ > +({ \ > + const u8 d[] =3D { seq }; \ > + struct drm_panel *panel =3D &(priv)->panel; \ > + struct device *dev =3D panel->dev; \ > + int ret; \ > + ret =3D mipi_dbi_command_stackbuf((priv)->dbi, cmd, d, ARRAY_SIZE(d)); \ > + if (ret) \ > + dev_err_ratelimited(dev, "error %d when sending command %#02x\n", ret,= cmd); \ > + ret; \ > +}) > + > +static int hitachi_tx10d07vm0baa_prepare(struct drm_panel *panel) > +{ > + struct hitachi_tx10d07vm0baa *priv =3D to_hitachi_tx10d07vm0baa(panel); > + struct device *dev =3D panel->dev; > + int ret; > + > + priv->dbi =3D dev_get_drvdata(dev->parent); > + if (!priv->dbi) > + return -ENODEV; > + > + gpiod_set_value_cansleep(priv->reset_gpio, 1); > + > + ret =3D regulator_bulk_enable(ARRAY_SIZE(hitachi_tx10d07vm0baa_supplies= ), priv->supplies); > + if (ret) { > + dev_err(dev, "failed to enable power supplies: %d\n", ret); > + return ret; > + } > + > + usleep_range(1000, 2000); > + > + gpiod_set_value_cansleep(priv->reset_gpio, 0); > + > + usleep_range(10000, 11000); > + > + return 0; > +}; > + > +static int hitachi_tx10d07vm0baa_enable(struct drm_panel *panel) > +{ > + struct hitachi_tx10d07vm0baa *priv =3D to_hitachi_tx10d07vm0baa(panel); > + > + panel_dbi_command(priv, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x03, 0x= 1f); [Severity: High] Can this dereference a NULL priv->dbi pointer in hitachi_tx10d07vm0baa_enable() and hitachi_tx10d07vm0baa_disable() if hitachi_tx10d07vm0baa_prepare() fails to obtain priv->dbi? In hitachi_tx10d07vm0baa_probe(), priv->dbi is left NULL and only looked up in hitachi_tx10d07vm0baa_prepare() via dev_get_drvdata(dev->parent). If dev_get_drvdata(dev->parent) returns NULL (for example, when the panel node is instantiated outside a bound tegra-dbi parent, as in the standalone OF-graph panel node shown in hit,tx10d07vm0baa.yaml, or after parent unbind= ), hitachi_tx10d07vm0baa_prepare() returns -ENODEV with priv->dbi still NULL a= nd panel->prepared remaining false. During an atomic modeset commit in drm_atomic_helper_commit_modeset_enables= (), panel_bridge_atomic_pre_enable() calls drm_panel_prepare(), which cannot abort the commit on error. Next, drm_atomic_helper_commit_encoder_bridge_enable() invokes panel_bridge_atomic_enable() (and tegra_dbi_atomic_enable() in commit "drm/tegra: Add support for 8-bit CPU interface"), which calls drm_panel_enable(panel). Because drm_panel_enable() checks panel->enabled but does not check panel->prepared: drivers/gpu/drm/drm_panel.c:drm_panel_enable() { ... if (panel->funcs && panel->funcs->enable) { ret =3D panel->funcs->enable(panel); if (ret < 0) goto exit; } ... } it proceeds to call hitachi_tx10d07vm0baa_enable() (and later hitachi_tx10d07vm0baa_disable()), passing priv->dbi =3D=3D NULL through panel_dbi_command() -> mipi_dbi_command_stackbuf() -> mipi_dbi_command_buf(= ): drivers/gpu/drm/drm_mipi_dbi.c:mipi_dbi_command_buf() { ... mutex_lock(&dbi->cmdlock); ret =3D dbi->command(dbi, cmdbuf, data, len); mutex_unlock(&dbi->cmdlock); ... } Would it make sense to look up priv->dbi in hitachi_tx10d07vm0baa_probe() (or guard against a NULL priv->dbi before issuing DBI commands)? [ ... ] --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261022132259.2407= 17-1-clamor95@gmail.com?part=3D2