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authorZhou Qingyang <zhou1615@umn.edu>2021-12-03 18:40:30 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-01-27 13:04:42 +0300
commitc3d14b3585b78a007ee99066698655662c61e4bd (patch)
tree5396a5be583bcffe8d59dc94166d80d74652c84a /drivers/media
parent84155d2b06060e13655495d295f70d39f5dd7144 (diff)
downloadlinux-c3d14b3585b78a007ee99066698655662c61e4bd.tar.xz
media: saa7146: hexium_gemini: Fix a NULL pointer dereference in hexium_attach()
[ Upstream commit 3af86b046933ba513d08399dba0d4d8b50d607d0 ] In hexium_attach(dev, info), saa7146_vv_init() is called to allocate a new memory for dev->vv_data. saa7146_vv_release() will be called on failure of saa7146_register_device(). There is a dereference of dev->vv_data in saa7146_vv_release(), which could lead to a NULL pointer dereference on failure of saa7146_vv_init(). Fix this bug by adding a check of saa7146_vv_init(). This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_VIDEO_HEXIUM_GEMINI=m show no new warnings, and our static analyzer no longer warns about this code. Link: https://lore.kernel.org/linux-media/20211203154030.111210-1-zhou1615@umn.edu Signed-off-by: Zhou Qingyang <zhou1615@umn.edu> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/common/saa7146/saa7146_fops.c2
-rw-r--r--drivers/media/pci/saa7146/hexium_gemini.c7
2 files changed, 7 insertions, 2 deletions
diff --git a/drivers/media/common/saa7146/saa7146_fops.c b/drivers/media/common/saa7146/saa7146_fops.c
index baf5772c52a9..be3215977714 100644
--- a/drivers/media/common/saa7146/saa7146_fops.c
+++ b/drivers/media/common/saa7146/saa7146_fops.c
@@ -521,7 +521,7 @@ int saa7146_vv_init(struct saa7146_dev* dev, struct saa7146_ext_vv *ext_vv)
ERR("out of memory. aborting.\n");
kfree(vv);
v4l2_ctrl_handler_free(hdl);
- return -1;
+ return -ENOMEM;
}
saa7146_video_uops.init(dev,vv);
diff --git a/drivers/media/pci/saa7146/hexium_gemini.c b/drivers/media/pci/saa7146/hexium_gemini.c
index 2214c74bbbf1..3947701cd6c7 100644
--- a/drivers/media/pci/saa7146/hexium_gemini.c
+++ b/drivers/media/pci/saa7146/hexium_gemini.c
@@ -284,7 +284,12 @@ static int hexium_attach(struct saa7146_dev *dev, struct saa7146_pci_extension_d
hexium_set_input(hexium, 0);
hexium->cur_input = 0;
- saa7146_vv_init(dev, &vv_data);
+ ret = saa7146_vv_init(dev, &vv_data);
+ if (ret) {
+ i2c_del_adapter(&hexium->i2c_adapter);
+ kfree(hexium);
+ return ret;
+ }
vv_data.vid_ops.vidioc_enum_input = vidioc_enum_input;
vv_data.vid_ops.vidioc_g_input = vidioc_g_input;