linux-stable.git/drivers/char/ipmi, branch v5.4.232 Linux kernel stable tree ipmi: fix use after free in _ipmi_destroy_user() 2023-01-18T10:41:49+00:00 Dan Carpenter error27@gmail.com 2022-11-15T13:17:43+00:00 d23006f2a56e11a3103de0ca8b843bf7fd7d76fc commit a92ce570c81dc0feaeb12a429b4bc65686d17967 upstream. The intf_free() function frees the "intf" pointer so we cannot dereference it again on the next line. Fixes: cbb79863fc31 ("ipmi: Don't allow device module unload when in use") Signed-off-by: Dan Carpenter <error27@gmail.com> Message-Id: <Y3M8xa1drZv4CToE@kili> Cc: <stable@vger.kernel.org> # 5.5+ Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a92ce570c81dc0feaeb12a429b4bc65686d17967 upstream.

The intf_free() function frees the "intf" pointer so we cannot
dereference it again on the next line.

Fixes: cbb79863fc31 ("ipmi: Don't allow device module unload when in use")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Message-Id: <Y3M8xa1drZv4CToE@kili>
Cc: <stable@vger.kernel.org> # 5.5+
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmi: fix long wait in unload when IPMI disconnect 2023-01-18T10:41:49+00:00 Zhang Yuchen zhangyuchen.lcr@bytedance.com 2022-10-07T09:26:16+00:00 74531c23adc5f9bcf417563758f0897e839bcecb commit f6f1234d98cce69578bfac79df147a1f6660596c upstream. When fixing the problem mentioned in PATCH1, we also found the following problem: If the IPMI is disconnected and in the sending process, the uninstallation driver will be stuck for a long time. The main problem is that uninstalling the driver waits for curr_msg to be sent or HOSED. After stopping tasklet, the only place to trigger the timeout mechanism is the circular poll in shutdown_smi. The poll function delays 10us and calls smi_event_handler(smi_info,10). Smi_event_handler deducts 10us from kcs->ibf_timeout. But the poll func is followed by schedule_timeout_uninterruptible(1). The time consumed here is not counted in kcs->ibf_timeout. So when 10us is deducted from kcs->ibf_timeout, at least 1 jiffies has actually passed. The waiting time has increased by more than a hundredfold. Now instead of calling poll(). call smi_event_handler() directly and calculate the elapsed time. For verification, you can directly use ebpf to check the kcs-> ibf_timeout for each call to kcs_event() when IPMI is disconnected. Decrement at normal rate before unloading. The decrement rate becomes very slow after unloading. $ bpftrace -e 'kprobe:kcs_event {printf("kcs->ibftimeout : %d\n", *(arg0+584));}' Signed-off-by: Zhang Yuchen <zhangyuchen.lcr@bytedance.com> Message-Id: <20221007092617.87597-3-zhangyuchen.lcr@bytedance.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f6f1234d98cce69578bfac79df147a1f6660596c upstream.

When fixing the problem mentioned in PATCH1, we also found
the following problem:

If the IPMI is disconnected and in the sending process, the
uninstallation driver will be stuck for a long time.

The main problem is that uninstalling the driver waits for curr_msg to
be sent or HOSED. After stopping tasklet, the only place to trigger the
timeout mechanism is the circular poll in shutdown_smi.

The poll function delays 10us and calls smi_event_handler(smi_info,10).
Smi_event_handler deducts 10us from kcs->ibf_timeout.

But the poll func is followed by schedule_timeout_uninterruptible(1).
The time consumed here is not counted in kcs->ibf_timeout.

So when 10us is deducted from kcs->ibf_timeout, at least 1 jiffies has
actually passed. The waiting time has increased by more than a
hundredfold.

Now instead of calling poll(). call smi_event_handler() directly and
calculate the elapsed time.

For verification, you can directly use ebpf to check the kcs->
ibf_timeout for each call to kcs_event() when IPMI is disconnected.
Decrement at normal rate before unloading. The decrement rate becomes
very slow after unloading.

  $ bpftrace -e 'kprobe:kcs_event {printf("kcs->ibftimeout : %d\n",
      *(arg0+584));}'

Signed-off-by: Zhang Yuchen <zhangyuchen.lcr@bytedance.com>
Message-Id: <20221007092617.87597-3-zhangyuchen.lcr@bytedance.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmi: fix memleak when unload ipmi driver 2023-01-18T10:41:35+00:00 Zhang Yuchen zhangyuchen.lcr@bytedance.com 2022-10-07T09:26:17+00:00 9066300fe8bf281fe3c8c55cbba70b8a61568155 [ Upstream commit 36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9 ] After the IPMI disconnect problem, the memory kept rising and we tried to unload the driver to free the memory. However, only part of the free memory is recovered after the driver is uninstalled. Using ebpf to hook free functions, we find that neither ipmi_user nor ipmi_smi_msg is free, only ipmi_recv_msg is free. We find that the deliver_smi_err_response call in clean_smi_msgs does the destroy processing on each message from the xmit_msg queue without checking the return value and free ipmi_smi_msg. deliver_smi_err_response is called only at this location. Adding the free handling has no effect. To verify, try using ebpf to trace the free function. $ bpftrace -e 'kretprobe:ipmi_alloc_recv_msg {printf("alloc rcv %p\n",retval);} kprobe:free_recv_msg {printf("free recv %p\n", arg0)} kretprobe:ipmi_alloc_smi_msg {printf("alloc smi %p\n", retval);} kprobe:free_smi_msg {printf("free smi %p\n",arg0)}' Signed-off-by: Zhang Yuchen <zhangyuchen.lcr@bytedance.com> Message-Id: <20221007092617.87597-4-zhangyuchen.lcr@bytedance.com> [Fixed the comment above handle_one_recv_msg().] Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 36992eb6b9b83f7f9cdc8e74fb5799d7b52e83e9 ]

After the IPMI disconnect problem, the memory kept rising and we tried
to unload the driver to free the memory. However, only part of the
free memory is recovered after the driver is uninstalled. Using
ebpf to hook free functions, we find that neither ipmi_user nor
ipmi_smi_msg is free, only ipmi_recv_msg is free.

We find that the deliver_smi_err_response call in clean_smi_msgs does
the destroy processing on each message from the xmit_msg queue without
checking the return value and free ipmi_smi_msg.

deliver_smi_err_response is called only at this location. Adding the
free handling has no effect.

To verify, try using ebpf to trace the free function.

  $ bpftrace -e 'kretprobe:ipmi_alloc_recv_msg {printf("alloc rcv
      %p\n",retval);} kprobe:free_recv_msg {printf("free recv %p\n",
      arg0)} kretprobe:ipmi_alloc_smi_msg {printf("alloc smi %p\n",
        retval);} kprobe:free_smi_msg {printf("free smi  %p\n",arg0)}'

Signed-off-by: Zhang Yuchen <zhangyuchen.lcr@bytedance.com>
Message-Id: <20221007092617.87597-4-zhangyuchen.lcr@bytedance.com>
[Fixed the comment above handle_one_recv_msg().]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipmi: Fix pr_fmt to avoid compilation issues 2022-06-14T16:11:28+00:00 Corey Minyard cminyard@mvista.com 2022-04-15T12:23:32+00:00 2d966c94adce2b405234d403b13bf3d41901949e [ Upstream commit 2ebaf18a0b7fb764bba6c806af99fe868cee93de ] The was it was wouldn't work in some situations, simplify it. What was there was unnecessary complexity. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2ebaf18a0b7fb764bba6c806af99fe868cee93de ]

The was it was wouldn't work in some situations, simplify it.  What was
there was unnecessary complexity.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipmi:ssif: Check for NULL msg when handling events and messages 2022-06-14T16:11:28+00:00 Corey Minyard cminyard@mvista.com 2022-04-01T12:44:53+00:00 2064a1eab2ec872faf77079d1b6c992d8a49e4ae [ Upstream commit 7602b957e2404e5f98d9a40b68f1fd27f0028712 ] Even though it's not possible to get into the SSIF_GETTING_MESSAGES and SSIF_GETTING_EVENTS states without a valid message in the msg field, it's probably best to be defensive here and check and print a log, since that means something else went wrong. Also add a default clause to that switch statement to release the lock and print a log, in case the state variable gets messed up somehow. Reported-by: Haowen Bai <baihaowen@meizu.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7602b957e2404e5f98d9a40b68f1fd27f0028712 ]

Even though it's not possible to get into the SSIF_GETTING_MESSAGES and
SSIF_GETTING_EVENTS states without a valid message in the msg field,
it's probably best to be defensive here and check and print a log, since
that means something else went wrong.

Also add a default clause to that switch statement to release the lock
and print a log, in case the state variable gets messed up somehow.

Reported-by: Haowen Bai <baihaowen@meizu.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipmi: fix initialization when workqueue allocation fails 2021-12-29T11:23:36+00:00 Thadeu Lima de Souza Cascardo cascardo@canonical.com 2021-12-17T15:44:10+00:00 8467c8cb94a406cc0c54d9306b61d0db86c94048 commit 75d70d76cb7b927cace2cb34265d68ebb3306b13 upstream. 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 <cascardo@canonical.com> Cc: Corey Minyard <cminyard@mvista.com> Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com> Cc: stable@vger.kernel.org Message-Id: <20211217154410.1228673-2-cascardo@canonical.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 75d70d76cb7b927cace2cb34265d68ebb3306b13 upstream.

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 <cascardo@canonical.com>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Cc: stable@vger.kernel.org
Message-Id: <20211217154410.1228673-2-cascardo@canonical.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmi: ssif: initialize ssif_info->client early 2021-12-29T11:23:36+00:00 Mian Yousaf Kaukab ykaukab@suse.de 2021-12-08T09:32:39+00:00 8efd6a3391f7b0b19fb0c38e50add06ca30c94af commit 34f35f8f14bc406efc06ee4ff73202c6fd245d15 upstream. 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 <tiwai@suse.de> Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de> Message-Id: <20211208093239.4432-1-ykaukab@suse.de> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 34f35f8f14bc406efc06ee4ff73202c6fd245d15 upstream.

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 <tiwai@suse.de>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Message-Id: <20211208093239.4432-1-ykaukab@suse.de>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmi: bail out if init_srcu_struct fails 2021-12-29T11:23:36+00:00 Thadeu Lima de Souza Cascardo cascardo@canonical.com 2021-12-17T15:44:09+00:00 cd24bafefc17947532008c3667637aee7471d7a8 commit 2b5160b12091285c5aca45980f100a9294af7b04 upstream. 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 <cascardo@canonical.com> Cc: Corey Minyard <cminyard@mvista.com> Cc: stable@vger.kernel.org Message-Id: <20211217154410.1228673-1-cascardo@canonical.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2b5160b12091285c5aca45980f100a9294af7b04 upstream.

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 <cascardo@canonical.com>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: stable@vger.kernel.org
Message-Id: <20211217154410.1228673-1-cascardo@canonical.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module 2021-12-29T11:23:34+00:00 Wu Bo wubo40@huawei.com 2021-12-21T07:00:34+00:00 992649b8b16843d27eb39ceea5f9cf85ffb50a18 [ Upstream commit ffb76a86f8096a8206be03b14adda6092e18e275 ] 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 <wubo40@huawei.com> Message-Id: <1640070034-56671-1-git-send-email-wubo40@huawei.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ffb76a86f8096a8206be03b14adda6092e18e275 ]

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 <wubo40@huawei.com>
Message-Id: <1640070034-56671-1-git-send-email-wubo40@huawei.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipmi: msghandler: Make symbol 'remove_work_wq' static 2021-12-08T08:01:15+00:00 Wei Yongjun weiyongjun1@huawei.com 2021-11-23T08:36:18+00:00 5df7d6a012fc5cfebaaa708b27b64592271467eb commit 5a3ba99b62d8486de0316334e72ac620d4b94fdd upstream. 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 <hulkci@huawei.com> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Message-Id: <20211123083618.2366808-1-weiyongjun1@huawei.com> Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5a3ba99b62d8486de0316334e72ac620d4b94fdd upstream.

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 <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Message-Id: <20211123083618.2366808-1-weiyongjun1@huawei.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>