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| author |   Wang Hai <wanghai38@huawei.com> | 2021-10-13 19:41:39 +0800 |
|---|---|---|
| committer |   Sam Ravnborg <sam@ravnborg.org> | 2021-10-14 21:39:02 +0200 |
| commit | acf20ed020ffa4d6cc8347e8d356509b95df3cbe (patch) | |
| tree | 6ec7fe3893e1c91d15f4f0161251280f0a42c43a | |
| parent | drm/panel-simple: Add Vivax TPC-9150 panel v6 (diff) | |
| download | linux-dev-acf20ed020ffa4d6cc8347e8d356509b95df3cbe.tar.xz linux-dev-acf20ed020ffa4d6cc8347e8d356509b95df3cbe.zip | |
drm: fix null-ptr-deref in drm_dev_init_release()
I got a null-ptr-deref report:
[drm:drm_dev_init [drm]] *ERROR* Cannot allocate anonymous inode: -12
==================================================================
BUG: KASAN: null-ptr-deref in iput+0x3c/0x4a0
...
Call Trace:
dump_stack_lvl+0x6c/0x8b
kasan_report.cold+0x64/0xdb
__asan_load8+0x69/0x90
iput+0x3c/0x4a0
drm_dev_init_release+0x39/0xb0 [drm]
drm_managed_release+0x158/0x2d0 [drm]
drm_dev_init+0x3a7/0x4c0 [drm]
__devm_drm_dev_alloc+0x55/0xd0 [drm]
mi0283qt_probe+0x8a/0x2b5 [mi0283qt]
spi_probe+0xeb/0x130
...
entry_SYSCALL_64_after_hwframe+0x44/0xae
If drm_fs_inode_new() fails in drm_dev_init(), dev->anon_inode will point
to PTR_ERR(...) instead of NULL. This will result in null-ptr-deref when
drm_fs_inode_free(dev->anon_inode) is called.
drm_dev_init()
drm_fs_inode_new() // fail, dev->anon_inode = PTR_ERR(...)
drm_managed_release()
drm_dev_init_release()
drm_fs_inode_free() // access non-existent anon_inode
Define a temp variable and assign it to dev->anon_inode if the temp
variable is not PTR_ERR.
Fixes: 2cbf7fc6718b ("drm: Use drmm_ for drm_dev_init cleanup")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211013114139.4042207-1-wanghai38@huawei.com
| -rw-r--r-- | drivers/gpu/drm/drm_drv.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index dc293b771c3f..8214a0b1ab7f 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -582,6 +582,7 @@ static int drm_dev_init(struct drm_device *dev, const struct drm_driver *driver, struct device *parent) { + struct inode *inode; int ret; if (!drm_core_init_complete) { @@ -618,13 +619,15 @@ static int drm_dev_init(struct drm_device *dev, if (ret) return ret; - dev->anon_inode = drm_fs_inode_new(); - if (IS_ERR(dev->anon_inode)) { - ret = PTR_ERR(dev->anon_inode); + inode = drm_fs_inode_new(); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret); goto err; } + dev->anon_inode = inode; + if (drm_core_check_feature(dev, DRIVER_RENDER)) { ret = drm_minor_alloc(dev, DRM_MINOR_RENDER); if (ret) |