From 34f35f8f14bc406efc06ee4ff73202c6fd245d15 Mon Sep 17 00:00:00 2001 From: Mian Yousaf Kaukab Date: Wed, 8 Dec 2021 10:32:39 +0100 Subject: ipmi: ssif: initialize ssif_info->client early 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 --- drivers/char/ipmi/ipmi_ssif.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c index 0c62e578749e..48aab77abebf 100644 --- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -1659,6 +1659,9 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id) } } + ssif_info->client = client; + i2c_set_clientdata(client, ssif_info); + rv = ssif_check_and_remove(client, ssif_info); /* If rv is 0 and addr source is not SI_ACPI, continue probing */ if (!rv && ssif_info->addr_source == SI_ACPI) { @@ -1679,9 +1682,6 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id) ipmi_addr_src_to_str(ssif_info->addr_source), client->addr, client->adapter->name, slave_addr); - ssif_info->client = client; - i2c_set_clientdata(client, ssif_info); - /* Now check for system interface capabilities */ msg[0] = IPMI_NETFN_APP_REQUEST << 2; msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD; @@ -1881,6 +1881,7 @@ static int ssif_probe(struct i2c_client *client, const struct i2c_device_id *id) dev_err(&ssif_info->client->dev, "Unable to start IPMI SSIF: %d\n", rv); + i2c_set_clientdata(client, NULL); kfree(ssif_info); } kfree(resp); -- cgit v1.2.3-70-g09d2 From 2b5160b12091285c5aca45980f100a9294af7b04 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Fri, 17 Dec 2021 12:44:09 -0300 Subject: ipmi: bail out if init_srcu_struct fails 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 --- drivers/char/ipmi/ipmi_msghandler.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index c837d5416e0e..84975b21fff2 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -5392,7 +5392,9 @@ static int ipmi_init_msghandler(void) if (initialized) goto out; - init_srcu_struct(&ipmi_interfaces_srcu); + rv = init_srcu_struct(&ipmi_interfaces_srcu); + if (rv) + goto out; timer_setup(&ipmi_timer, ipmi_timeout, 0); mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES); -- cgit v1.2.3-70-g09d2 From 75d70d76cb7b927cace2cb34265d68ebb3306b13 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Fri, 17 Dec 2021 12:44:10 -0300 Subject: ipmi: fix initialization when workqueue allocation fails 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 --- drivers/char/ipmi/ipmi_msghandler.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 84975b21fff2..266c7bc58dda 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -5396,20 +5396,23 @@ static int ipmi_init_msghandler(void) if (rv) goto out; - timer_setup(&ipmi_timer, ipmi_timeout, 0); - mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES); - - atomic_notifier_chain_register(&panic_notifier_list, &panic_block); - remove_work_wq = create_singlethread_workqueue("ipmi-msghandler-remove-wq"); if (!remove_work_wq) { pr_err("unable to create ipmi-msghandler-remove-wq workqueue"); rv = -ENOMEM; - goto out; + goto out_wq; } + timer_setup(&ipmi_timer, ipmi_timeout, 0); + mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES); + + atomic_notifier_chain_register(&panic_notifier_list, &panic_block); + initialized = true; +out_wq: + if (rv) + cleanup_srcu_struct(&ipmi_interfaces_srcu); out: mutex_unlock(&ipmi_interfaces_mutex); return rv; -- cgit v1.2.3-70-g09d2 From ffb76a86f8096a8206be03b14adda6092e18e275 Mon Sep 17 00:00:00 2001 From: Wu Bo Date: Tue, 21 Dec 2021 15:00:34 +0800 Subject: ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module 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 --- drivers/char/ipmi/ipmi_msghandler.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 266c7bc58dda..c59265146e9c 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -3031,7 +3031,7 @@ cleanup_bmc_device(struct kref *ref) * with removing the device attributes while reading a device * attribute. */ - schedule_work(&bmc->remove_work); + queue_work(remove_work_wq, &bmc->remove_work); } /* -- cgit v1.2.3-70-g09d2