From: Ma Ke make24@iscas.ac.cn

stable inclusion from stable-v4.19.317 commit ffabad4aa91e33ced3c6ae793fb37771b3e9cb51 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAGEON CVE: CVE-2024-41089

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 6d411c8ccc0137a612e0044489030a194ff5c843 upstream.

In nv17_tv_get_hd_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a possible NULL pointer dereference on failure of drm_mode_duplicate(). The same applies to drm_cvt_mode(). Add a check to avoid null pointer dereference.

Cc: stable@vger.kernel.org Signed-off-by: Ma Ke make24@iscas.ac.cn Signed-off-by: Lyude Paul lyude@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/20240625081029.2619437-1-make2... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Liu Mingrui liumingrui@huawei.com --- drivers/gpu/drm/nouveau/dispnv04/tvnv17.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c index 8fd8124d72ba..3922731361e1 100644 --- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c +++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c @@ -257,6 +257,8 @@ static int nv17_tv_get_hd_modes(struct drm_encoder *encoder, if (modes[i].hdisplay == output_mode->hdisplay && modes[i].vdisplay == output_mode->vdisplay) { mode = drm_mode_duplicate(encoder->dev, output_mode); + if (!mode) + continue; mode->type |= DRM_MODE_TYPE_PREFERRED;

} else { @@ -264,6 +266,8 @@ static int nv17_tv_get_hd_modes(struct drm_encoder *encoder, modes[i].vdisplay, 60, false, (output_mode->flags & DRM_MODE_FLAG_INTERLACE), false); + if (!mode) + continue; }

/* CVT modes are sometimes unsuitable... */