From 7194b62c8c99727e3f145b00b8390a905252370e Mon Sep 17 00:00:00 2001 From: Stephane Viau Date: Tue, 5 May 2015 09:47:57 -0400 Subject: [PATCH] drm/msm: fix unbalanced DRM framebuffer init/destroy When msm_framebuffer_init() fails before calling drm_framebuffer_init(), drm_framebuffer_cleanup() [called in msm_framebuffer_destroy()] is still being called even though drm_framebuffer_init() was not called for that buffer. Thus a NULL pointer derefencing: [ 247.529691] Unable to handle kernel NULL pointer dereference at virtual address 0000027c ... [ 247.563996] PC is at __mutex_lock_slowpath+0x94/0x3a8 ... [ 247.823025] [] (__mutex_lock_slowpath) from [] (mutex_lock+0x20/0x3c) [ 247.831186] [] (mutex_lock) from [] (drm_framebuffer_cleanup+0x18/0x38) [ 247.839520] [] (drm_framebuffer_cleanup) from [] (msm_framebuffer_destroy+0x48/0x100) [ 247.849066] [] (msm_framebuffer_destroy) from [] (msm_framebuffer_init+0x1e8/0x228) [ 247.858439] [] (msm_framebuffer_init) from [] (msm_framebuffer_create+0x70/0x134) [ 247.867642] [] (msm_framebuffer_create) from [] (internal_framebuffer_create+0x67c/0x7b4) [ 247.877537] [] (internal_framebuffer_create) from [] (drm_mode_addfb2+0x20/0x98) [ 247.886650] [] (drm_mode_addfb2) from [] (drm_ioctl+0x240/0x420) [ 247.894378] [] (drm_ioctl) from [] (do_vfs_ioctl+0x4e4/0x5a4) ... Signed-off-by: Stephane Viau [plus initialize msm_fb to NULL to -Rob] Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/msm_fb.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_fb.c b/drivers/gpu/drm/msm/msm_fb.c index 6b573e612f27..121713281417 100644 --- a/drivers/gpu/drm/msm/msm_fb.c +++ b/drivers/gpu/drm/msm/msm_fb.c @@ -172,8 +172,8 @@ struct drm_framebuffer *msm_framebuffer_init(struct drm_device *dev, { struct msm_drm_private *priv = dev->dev_private; struct msm_kms *kms = priv->kms; - struct msm_framebuffer *msm_fb; - struct drm_framebuffer *fb = NULL; + struct msm_framebuffer *msm_fb = NULL; + struct drm_framebuffer *fb; const struct msm_format *format; int ret, i, n; unsigned int hsub, vsub; @@ -239,8 +239,7 @@ struct drm_framebuffer *msm_framebuffer_init(struct drm_device *dev, return fb; fail: - if (fb) - msm_framebuffer_destroy(fb); + kfree(msm_fb); return ERR_PTR(ret); } -- 2.30.2