From: Stephane Viau <sviau@codeaurora.org>
To: dri-devel@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
robdclark@gmail.com, Stephane Viau <sviau@codeaurora.org>
Subject: [PATCH] drm/msm: fix unbalanced DRM framebuffer init/destroy
Date: Tue, 5 May 2015 09:47:57 -0400 [thread overview]
Message-ID: <1430833677-16010-1-git-send-email-sviau@codeaurora.org> (raw)
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] [<c07c3c78>] (__mutex_lock_slowpath) from [<c07c3fac>] (mutex_lock+0x20/0x3c)
[ 247.831186] [<c07c3fac>] (mutex_lock) from [<c0347cf0>] (drm_framebuffer_cleanup+0x18/0x38)
[ 247.839520] [<c0347cf0>] (drm_framebuffer_cleanup) from [<c036d138>] (msm_framebuffer_destroy+0x48/0x100)
[ 247.849066] [<c036d138>] (msm_framebuffer_destroy) from [<c036d580>] (msm_framebuffer_init+0x1e8/0x228)
[ 247.858439] [<c036d580>] (msm_framebuffer_init) from [<c036d630>] (msm_framebuffer_create+0x70/0x134)
[ 247.867642] [<c036d630>] (msm_framebuffer_create) from [<c03493ec>] (internal_framebuffer_create+0x67c/0x7b4)
[ 247.877537] [<c03493ec>] (internal_framebuffer_create) from [<c034ce34>] (drm_mode_addfb2+0x20/0x98)
[ 247.886650] [<c034ce34>] (drm_mode_addfb2) from [<c034071c>] (drm_ioctl+0x240/0x420)
[ 247.894378] [<c034071c>] (drm_ioctl) from [<c011df7c>] (do_vfs_ioctl+0x4e4/0x5a4)
...
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
---
drivers/gpu/drm/msm/msm_fb.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_fb.c b/drivers/gpu/drm/msm/msm_fb.c
index 6b573e6..c0f09d3 100644
--- a/drivers/gpu/drm/msm/msm_fb.c
+++ b/drivers/gpu/drm/msm/msm_fb.c
@@ -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);
}
--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
reply other threads:[~2015-05-05 13:48 UTC|newest]
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