From: bumwoo lee <bw365.lee@samsung.com> stable inclusion from stable-v4.19.247 commit cb81ea998c461868d1168411a867d8ffee12f23f category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBP2KJ CVE: CVE-2022-49308 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 5dcc2afe716d69f5112ce035cb14f007461ff189 ] Currently, someone can invoke the sysfs such as state_show() intermittently before dev_set_drvdata() is done. And it can be a cause of kernel Oops because of edev is Null at that time. So modified the driver registration to after setting drviver data. - Oops's backtrace. Backtrace: [<c067865c>] (state_show) from [<c05222e8>] (dev_attr_show) [<c05222c0>] (dev_attr_show) from [<c02c66e0>] (sysfs_kf_seq_show) [<c02c6648>] (sysfs_kf_seq_show) from [<c02c496c>] (kernfs_seq_show) [<c02c4938>] (kernfs_seq_show) from [<c025e2a0>] (seq_read) [<c025e11c>] (seq_read) from [<c02c50a0>] (kernfs_fop_read) [<c02c5064>] (kernfs_fop_read) from [<c0231cac>] (__vfs_read) [<c0231c5c>] (__vfs_read) from [<c0231ee0>] (vfs_read) [<c0231e34>] (vfs_read) from [<c0232464>] (ksys_read) [<c02323f0>] (ksys_read) from [<c02324fc>] (sys_read) [<c02324e4>] (sys_read) from [<c00091d0>] (__sys_trace_return) Signed-off-by: bumwoo lee <bw365.lee@samsung.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Hongbo Li <lihongbo22@huawei.com> --- drivers/extcon/extcon.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c index e70f21ae85ff..4c70136c7aa3 100644 --- a/drivers/extcon/extcon.c +++ b/drivers/extcon/extcon.c @@ -1245,19 +1245,14 @@ int extcon_dev_register(struct extcon_dev *edev) edev->dev.type = &edev->extcon_dev_type; } - ret = device_register(&edev->dev); - if (ret) { - put_device(&edev->dev); - goto err_dev; - } - spin_lock_init(&edev->lock); - edev->nh = devm_kcalloc(&edev->dev, edev->max_supported, - sizeof(*edev->nh), GFP_KERNEL); - if (!edev->nh) { - ret = -ENOMEM; - device_unregister(&edev->dev); - goto err_dev; + if (edev->max_supported) { + edev->nh = kcalloc(edev->max_supported, sizeof(*edev->nh), + GFP_KERNEL); + if (!edev->nh) { + ret = -ENOMEM; + goto err_alloc_nh; + } } for (index = 0; index < edev->max_supported; index++) @@ -1268,6 +1263,12 @@ int extcon_dev_register(struct extcon_dev *edev) dev_set_drvdata(&edev->dev, edev); edev->state = 0; + ret = device_register(&edev->dev); + if (ret) { + put_device(&edev->dev); + goto err_dev; + } + mutex_lock(&extcon_dev_list_lock); list_add(&edev->entry, &extcon_dev_list); mutex_unlock(&extcon_dev_list_lock); @@ -1275,6 +1276,9 @@ int extcon_dev_register(struct extcon_dev *edev) return 0; err_dev: + if (edev->max_supported) + kfree(edev->nh); +err_alloc_nh: if (edev->max_supported) kfree(edev->extcon_dev_type.groups); err_alloc_groups: @@ -1335,6 +1339,7 @@ void extcon_dev_unregister(struct extcon_dev *edev) if (edev->max_supported) { kfree(edev->extcon_dev_type.groups); kfree(edev->cables); + kfree(edev->nh); } put_device(&edev->dev); -- 2.34.1