From: Lv Yunlong lyl2019@mail.ustc.edu.cn

stable inclusion from stable-v4.19.198 commit 481a76d4749ee3a27f902ba213fdcbb4bb39720e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RLTD CVE: CVE-2021-47334

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 7272b591c4cb9327c43443f67b8fbae7657dd9ae ]

In ibmasm_init_one, it calls ibmasm_init_remote_input_dev(). Inside ibmasm_init_remote_input_dev, mouse_dev and keybd_dev are allocated by input_allocate_device(), and assigned to sp->remote.mouse_dev and sp->remote.keybd_dev respectively.

In the err_free_devices error branch of ibmasm_init_one, mouse_dev and keybd_dev are freed by input_free_device(), and return error. Then the execution runs into error_send_message error branch of ibmasm_init_one, where ibmasm_free_remote_input_dev(sp) is called to unregister the freed sp->remote.mouse_dev and sp->remote.keybd_dev.

My patch add a "error_init_remote" label to handle the error of ibmasm_init_remote_input_dev(), to avoid the uaf bugs.

Signed-off-by: Lv Yunlong lyl2019@mail.ustc.edu.cn Link: https://lore.kernel.org/r/20210426170620.10546-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zhang Changzhong zhangchangzhong@huawei.com --- drivers/misc/ibmasm/module.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/ibmasm/module.c b/drivers/misc/ibmasm/module.c index e914b8c..9f83441 100644 --- a/drivers/misc/ibmasm/module.c +++ b/drivers/misc/ibmasm/module.c @@ -125,7 +125,7 @@ static int ibmasm_init_one(struct pci_dev *pdev, const struct pci_device_id *id) result = ibmasm_init_remote_input_dev(sp); if (result) { dev_err(sp->dev, "Failed to initialize remote queue\n"); - goto error_send_message; + goto error_init_remote; }

result = ibmasm_send_driver_vpd(sp); @@ -145,8 +145,9 @@ static int ibmasm_init_one(struct pci_dev *pdev, const struct pci_device_id *id) return 0;

error_send_message: - disable_sp_interrupts(sp->base_address); ibmasm_free_remote_input_dev(sp); +error_init_remote: + disable_sp_interrupts(sp->base_address); free_irq(sp->irq, (void *)sp); error_request_irq: iounmap(sp->base_address);