linux/drivers/char/ipmi, branch v5.17

ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module

2021-12-21T14:04:42Z

Hi, When testing install and uninstall of ipmi_si.ko and ipmi_msghandler.ko, the system crashed. The log as follows: [ 141.087026] BUG: unable to handle kernel paging request at ffffffffc09b3a5a [ 141.087241] PGD 8fe4c0d067 P4D 8fe4c0d067 PUD 8fe4c0f067 PMD 103ad89067 PTE 0 [ 141.087464] Oops: 0010 [#1] SMP NOPTI [ 141.087580] CPU: 67 PID: 668 Comm: kworker/67:1 Kdump: loaded Not tainted 4.18.0.x86_64 #47 [ 141.088009] Workqueue: events 0xffffffffc09b3a40 [ 141.088009] RIP: 0010:0xffffffffc09b3a5a [ 141.088009] Code: Bad RIP value. [ 141.088009] RSP: 0018:ffffb9094e2c3e88 EFLAGS: 00010246 [ 141.088009] RAX: 0000000000000000 RBX: ffff9abfdb1f04a0 RCX: 0000000000000000 [ 141.088009] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 [ 141.088009] RBP: 0000000000000000 R08: ffff9abfffee3cb8 R09: 00000000000002e1 [ 141.088009] R10: ffffb9094cb73d90 R11: 00000000000f4240 R12: ffff9abfffee8700 [ 141.088009] R13: 0000000000000000 R14: ffff9abfdb1f04a0 R15: ffff9abfdb1f04a8 [ 141.088009] FS: 0000000000000000(0000) GS:ffff9abfffec0000(0000) knlGS:0000000000000000 [ 141.088009] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 141.088009] CR2: ffffffffc09b3a30 CR3: 0000008fe4c0a001 CR4: 00000000007606e0 [ 141.088009] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 141.088009] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 141.088009] PKRU: 55555554 [ 141.088009] Call Trace: [ 141.088009] ? process_one_work+0x195/0x390 [ 141.088009] ? worker_thread+0x30/0x390 [ 141.088009] ? process_one_work+0x390/0x390 [ 141.088009] ? kthread+0x10d/0x130 [ 141.088009] ? kthread_flush_work_fn+0x10/0x10 [ 141.088009] ? ret_from_fork+0x35/0x40] BUG: unable to handle kernel paging request at ffffffffc0b28a5a [ 200.223240] PGD 97fe00d067 P4D 97fe00d067 PUD 97fe00f067 PMD a580cbf067 PTE 0 [ 200.223464] Oops: 0010 [#1] SMP NOPTI [ 200.223579] CPU: 63 PID: 664 Comm: kworker/63:1 Kdump: loaded Not tainted 4.18.0.x86_64 #46 [ 200.224008] Workqueue: events 0xffffffffc0b28a40 [ 200.224008] RIP: 0010:0xffffffffc0b28a5a [ 200.224008] Code: Bad RIP value. [ 200.224008] RSP: 0018:ffffbf3c8e2a3e88 EFLAGS: 00010246 [ 200.224008] RAX: 0000000000000000 RBX: ffffa0799ad6bca0 RCX: 0000000000000000 [ 200.224008] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 [ 200.224008] RBP: 0000000000000000 R08: ffff9fe43fde3cb8 R09: 00000000000000d5 [ 200.224008] R10: ffffbf3c8cb53d90 R11: 00000000000f4240 R12: ffff9fe43fde8700 [ 200.224008] R13: 0000000000000000 R14: ffffa0799ad6bca0 R15: ffffa0799ad6bca8 [ 200.224008] FS: 0000000000000000(0000) GS:ffff9fe43fdc0000(0000) knlGS:0000000000000000 [ 200.224008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 200.224008] CR2: ffffffffc0b28a30 CR3: 00000097fe00a002 CR4: 00000000007606e0 [ 200.224008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 200.224008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 200.224008] PKRU: 55555554 [ 200.224008] Call Trace: [ 200.224008] ? process_one_work+0x195/0x390 [ 200.224008] ? worker_thread+0x30/0x390 [ 200.224008] ? process_one_work+0x390/0x390 [ 200.224008] ? kthread+0x10d/0x130 [ 200.224008] ? kthread_flush_work_fn+0x10/0x10 [ 200.224008] ? ret_from_fork+0x35/0x40 [ 200.224008] kernel fault(0x1) notification starting on CPU 63 [ 200.224008] kernel fault(0x1) notification finished on CPU 63 [ 200.224008] CR2: ffffffffc0b28a5a [ 200.224008] ---[ end trace c82a412d93f57412 ]--- The reason is as follows: T1: rmmod ipmi_si. ->ipmi_unregister_smi() -> ipmi_bmc_unregister() -> __ipmi_bmc_unregister() -> kref_put(&bmc->usecount, cleanup_bmc_device); -> schedule_work(&bmc->remove_work); T2: rmmod ipmi_msghandler. ipmi_msghander module uninstalled, and the module space will be freed. T3: bmc->remove_work doing cleanup the bmc resource. -> cleanup_bmc_work() -> platform_device_unregister(&bmc->pdev); -> platform_device_del(pdev); -> device_del(&pdev->dev); -> kobject_uevent(&dev->kobj, KOBJ_REMOVE); -> kobject_uevent_env() -> dev_uevent() -> if (dev->type && dev->type->name) 'dev->type'(bmc_device_type) pointer space has freed when uninstall ipmi_msghander module, 'dev->type->name' cause the system crash. drivers/char/ipmi/ipmi_msghandler.c: 2820 static const struct device_type bmc_device_type = { 2821 .groups = bmc_dev_attr_groups, 2822 }; Steps to reproduce: Add a time delay in cleanup_bmc_work() function, and uninstall ipmi_si and ipmi_msghandler module. 2910 static void cleanup_bmc_work(struct work_struct *work) 2911 { 2912 struct bmc_device *bmc = container_of(work, struct bmc_device, 2913 remove_work); 2914 int id = bmc->pdev.id; /* Unregister overwrites id */ 2915 2916 msleep(3000); <--- 2917 platform_device_unregister(&bmc->pdev); 2918 ida_simple_remove(&ipmi_bmc_ida, id); 2919 } Use 'remove_work_wq' instead of 'system_wq' to solve this issues. Fixes: b2cfd8ab4add ("ipmi: Rework device id and guid handling to catch changing BMCs") Signed-off-by: Wu Bo Message-Id: <1640070034-56671-1-git-send-email-wubo40@huawei.com> Signed-off-by: Corey Minyard

ipmi: fix initialization when workqueue allocation fails

2021-12-17T20:39:03Z

If the workqueue allocation fails, the driver is marked as not initialized, and timer and panic_notifier will be left registered. Instead of removing those when workqueue allocation fails, do the workqueue initialization before doing it, and cleanup srcu_struct if it fails. Fixes: 1d49eb91e86e ("ipmi: Move remove_work to dedicated workqueue") Signed-off-by: Thadeu Lima de Souza Cascardo Cc: Corey Minyard Cc: Ioanna Alifieraki Cc: stable@vger.kernel.org Message-Id: <20211217154410.1228673-2-cascardo@canonical.com> Signed-off-by: Corey Minyard

ipmi: bail out if init_srcu_struct fails

2021-12-17T20:39:03Z

In case, init_srcu_struct fails (because of memory allocation failure), we might proceed with the driver initialization despite srcu_struct not being entirely initialized. Fixes: 913a89f009d9 ("ipmi: Don't initialize anything in the core until something uses it") Signed-off-by: Thadeu Lima de Souza Cascardo Cc: Corey Minyard Cc: stable@vger.kernel.org Message-Id: <20211217154410.1228673-1-cascardo@canonical.com> Signed-off-by: Corey Minyard

ipmi: ssif: initialize ssif_info->client early

2021-12-08T13:13:37Z

During probe ssif_info->client is dereferenced in error path. However, it is set when some of the error checking has already been done. This causes following kernel crash if an error path is taken: [ 30.645593][ T674] ipmi_ssif 0-000e: ipmi_ssif: Not probing, Interface already present [ 30.657616][ T674] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000088 ... [ 30.657723][ T674] pc : __dev_printk+0x28/0xa0 [ 30.657732][ T674] lr : _dev_err+0x7c/0xa0 ... [ 30.657772][ T674] Call trace: [ 30.657775][ T674] __dev_printk+0x28/0xa0 [ 30.657778][ T674] _dev_err+0x7c/0xa0 [ 30.657781][ T674] ssif_probe+0x548/0x900 [ipmi_ssif 62ce4b08badc1458fd896206d9ef69a3c31f3d3e] [ 30.657791][ T674] i2c_device_probe+0x37c/0x3c0 ... Initialize ssif_info->client before any error path can be taken. Clear i2c_client data in the error path to prevent the dangling pointer from leaking. Fixes: c4436c9149c5 ("ipmi_ssif: avoid registering duplicate ssif interface") Cc: stable@vger.kernel.org # 5.4.x Suggested-by: Takashi Iwai Signed-off-by: Mian Yousaf Kaukab Message-Id: <20211208093239.4432-1-ykaukab@suse.de> Signed-off-by: Corey Minyard

ipmi:ipmb: Fix unknown command response

2021-11-26T03:17:55Z

More missed changes, the response back to another system sending a command that had no user to handle it wasn't formatted properly. Signed-off-by: Corey Minyard

ipmi: fix IPMI_SMI_MSG_TYPE_IPMB_DIRECT response length checking

2021-11-26T03:17:55Z

A couple of issues: The tested data sizes are wrong; during the design that changed and this got missed. The formatting of the reponse couldn't use the normal one, it has to be an IPMB formatted response. Reported-by: Jakub Kicinski Fixes: 059747c245f0 ("ipmi: Add support for IPMB direct messages") Signed-off-by: Corey Minyard

ipmi: fix oob access due to uninit smi_msg type

2021-11-25T14:21:13Z

We're hitting OOB accesses in handle_ipmb_direct_rcv_rsp() (memcpy of size -1) after user space generates a message. Looks like the message is incorrectly assumed to be of the new IPMB type, because type is never set and message is allocated with kmalloc() not kzalloc(). Fixes: 059747c245f0 ("ipmi: Add support for IPMB direct messages") Signed-off-by: Jakub Kicinski Message-Id: <20211124210323.1950976-1-kuba@kernel.org> Signed-off-by: Corey Minyard

ipmi: msghandler: Make symbol 'remove_work_wq' static

2021-11-23T12:45:00Z

The sparse tool complains as follows: drivers/char/ipmi/ipmi_msghandler.c:194:25: warning: symbol 'remove_work_wq' was not declared. Should it be static? This symbol is not used outside of ipmi_msghandler.c, so marks it static. Fixes: 1d49eb91e86e ("ipmi: Move remove_work to dedicated workqueue") Reported-by: Hulk Robot Signed-off-by: Wei Yongjun Message-Id: <20211123083618.2366808-1-weiyongjun1@huawei.com> Signed-off-by: Corey Minyard

ipmi: Move remove_work to dedicated workqueue

2021-11-15T14:45:14Z

Currently when removing an ipmi_user the removal is deferred as a work on the system's workqueue. Although this guarantees the free operation will occur in non atomic context, it can race with the ipmi_msghandler module removal (see [1]) . In case a remove_user work is scheduled for removal and shortly after ipmi_msghandler module is removed we can end up in a situation where the module is removed fist and when the work is executed the system crashes with : BUG: unable to handle page fault for address: ffffffffc05c3450 PF: supervisor instruction fetch in kernel mode PF: error_code(0x0010) - not-present page because the pages of the module are gone. In cleanup_ipmi() there is no easy way to detect if there are any pending works to flush them before removing the module. This patch creates a separate workqueue and schedules the remove_work works on it. When removing the module the workqueue is drained when destroyed to avoid the race. [1] https://bugs.launchpad.net/bugs/1950666 Cc: stable@vger.kernel.org # 5.1 Fixes: 3b9a907223d7 (ipmi: fix sleep-in-atomic in free_user at cleanup SRCU user->release_barrier) Signed-off-by: Ioanna Alifieraki Message-Id: <20211115131645.25116-1-ioanna-maria.alifieraki@canonical.com> Signed-off-by: Corey Minyard

ipmi: kcs_bmc: Fix a memory leak in the error handling path of 'kcs_bmc_serio_add_device()'

2021-10-29T12:23:59Z

In the unlikely event where 'devm_kzalloc()' fails and 'kzalloc()' succeeds, 'port' would be leaking. Test each allocation separately to avoid the leak. Fixes: 3a3d2f6a4c64 ("ipmi: kcs_bmc: Add serio adaptor") Signed-off-by: Christophe JAILLET Message-Id: Reviewed-by: Andrew Jeffery Signed-off-by: Corey Minyard