<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/char, branch v5.16.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>random: fix crash on multiple early calls to add_bootloader_randomness()</title>
<updated>2022-01-16T08:11:14+00:00</updated>
<author>
<name>Dominik Brodowski</name>
<email>linux@dominikbrodowski.net</email>
</author>
<published>2021-12-29T21:10:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e65c79ffa96196f8df8a88f29970c8e4b458c2f8'/>
<id>e65c79ffa96196f8df8a88f29970c8e4b458c2f8</id>
<content type='text'>
commit f7e67b8e803185d0aabe7f29d25a35c8be724a78 upstream.

Currently, if CONFIG_RANDOM_TRUST_BOOTLOADER is enabled, multiple calls
to add_bootloader_randomness() are broken and can cause a NULL pointer
dereference, as noted by Ivan T. Ivanov. This is not only a hypothetical
problem, as qemu on arm64 may provide bootloader entropy via EFI and via
devicetree.

On the first call to add_hwgenerator_randomness(), crng_fast_load() is
executed, and if the seed is long enough, crng_init will be set to 1.
On subsequent calls to add_bootloader_randomness() and then to
add_hwgenerator_randomness(), crng_fast_load() will be skipped. Instead,
wait_event_interruptible() and then credit_entropy_bits() will be called.
If the entropy count for that second seed is large enough, that proceeds
to crng_reseed().

However, both wait_event_interruptible() and crng_reseed() depends
(at least in numa_crng_init()) on workqueues. Therefore, test whether
system_wq is already initialized, which is a sufficient indicator that
workqueue_init_early() has progressed far enough.

If we wind up hitting the !system_wq case, we later want to do what
would have been done there when wqs are up, so set a flag, and do that
work later from the rand_initialize() call.

Reported-by: Ivan T. Ivanov &lt;iivanov@suse.de&gt;
Fixes: 18b915ac6b0a ("efi/random: Treat EFI_RNG_PROTOCOL output as bootloader randomness")
Cc: stable@vger.kernel.org
Signed-off-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
[Jason: added crng_need_done state and related logic.]
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f7e67b8e803185d0aabe7f29d25a35c8be724a78 upstream.

Currently, if CONFIG_RANDOM_TRUST_BOOTLOADER is enabled, multiple calls
to add_bootloader_randomness() are broken and can cause a NULL pointer
dereference, as noted by Ivan T. Ivanov. This is not only a hypothetical
problem, as qemu on arm64 may provide bootloader entropy via EFI and via
devicetree.

On the first call to add_hwgenerator_randomness(), crng_fast_load() is
executed, and if the seed is long enough, crng_init will be set to 1.
On subsequent calls to add_bootloader_randomness() and then to
add_hwgenerator_randomness(), crng_fast_load() will be skipped. Instead,
wait_event_interruptible() and then credit_entropy_bits() will be called.
If the entropy count for that second seed is large enough, that proceeds
to crng_reseed().

However, both wait_event_interruptible() and crng_reseed() depends
(at least in numa_crng_init()) on workqueues. Therefore, test whether
system_wq is already initialized, which is a sufficient indicator that
workqueue_init_early() has progressed far enough.

If we wind up hitting the !system_wq case, we later want to do what
would have been done there when wqs are up, so set a flag, and do that
work later from the rand_initialize() call.

Reported-by: Ivan T. Ivanov &lt;iivanov@suse.de&gt;
Fixes: 18b915ac6b0a ("efi/random: Treat EFI_RNG_PROTOCOL output as bootloader randomness")
Cc: stable@vger.kernel.org
Signed-off-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
[Jason: added crng_need_done state and related logic.]
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>random: fix data race on crng init time</title>
<updated>2022-01-16T08:11:14+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2021-12-20T22:41:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=49005ba11d05506b3841b134daa346fee367825b'/>
<id>49005ba11d05506b3841b134daa346fee367825b</id>
<content type='text'>
commit 009ba8568be497c640cab7571f7bfd18345d7b24 upstream.

_extract_crng() does plain loads of crng-&gt;init_time and
crng_global_init_time, which causes undefined behavior if
crng_reseed() and RNDRESEEDCRNG modify these corrently.

Use READ_ONCE() and WRITE_ONCE() to make the behavior defined.

Don't fix the race on crng-&gt;init_time by protecting it with crng-&gt;lock,
since it's not a problem for duplicate reseedings to occur.  I.e., the
lockless access with READ_ONCE() is fine.

Fixes: d848e5f8e1eb ("random: add new ioctl RNDRESEEDCRNG")
Fixes: e192be9d9a30 ("random: replace non-blocking pool with a Chacha20-based CRNG")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 009ba8568be497c640cab7571f7bfd18345d7b24 upstream.

_extract_crng() does plain loads of crng-&gt;init_time and
crng_global_init_time, which causes undefined behavior if
crng_reseed() and RNDRESEEDCRNG modify these corrently.

Use READ_ONCE() and WRITE_ONCE() to make the behavior defined.

Don't fix the race on crng-&gt;init_time by protecting it with crng-&gt;lock,
since it's not a problem for duplicate reseedings to occur.  I.e., the
lockless access with READ_ONCE() is fine.

Fixes: d848e5f8e1eb ("random: add new ioctl RNDRESEEDCRNG")
Fixes: e192be9d9a30 ("random: replace non-blocking pool with a Chacha20-based CRNG")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>random: fix data race on crng_node_pool</title>
<updated>2022-01-16T08:11:14+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2021-12-20T22:41:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c1bdbdc7f5e2c73f2ca3d5063aa5980f8d9302dd'/>
<id>c1bdbdc7f5e2c73f2ca3d5063aa5980f8d9302dd</id>
<content type='text'>
commit 5d73d1e320c3fd94ea15ba5f79301da9a8bcc7de upstream.

extract_crng() and crng_backtrack_protect() load crng_node_pool with a
plain load, which causes undefined behavior if do_numa_crng_init()
modifies it concurrently.

Fix this by using READ_ONCE().  Note: as per the previous discussion
https://lore.kernel.org/lkml/20211219025139.31085-1-ebiggers@kernel.org/T/#u,
READ_ONCE() is believed to be sufficient here, and it was requested that
it be used here instead of smp_load_acquire().

Also change do_numa_crng_init() to set crng_node_pool using
cmpxchg_release() instead of mb() + cmpxchg(), as the former is
sufficient here but is more lightweight.

Fixes: 1e7f583af67b ("random: make /dev/urandom scalable for silly userspace programs")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5d73d1e320c3fd94ea15ba5f79301da9a8bcc7de upstream.

extract_crng() and crng_backtrack_protect() load crng_node_pool with a
plain load, which causes undefined behavior if do_numa_crng_init()
modifies it concurrently.

Fix this by using READ_ONCE().  Note: as per the previous discussion
https://lore.kernel.org/lkml/20211219025139.31085-1-ebiggers@kernel.org/T/#u,
READ_ONCE() is believed to be sufficient here, and it was requested that
it be used here instead of smp_load_acquire().

Also change do_numa_crng_init() to set crng_node_pool using
cmpxchg_release() instead of mb() + cmpxchg(), as the former is
sufficient here but is more lightweight.

Fixes: 1e7f583af67b ("random: make /dev/urandom scalable for silly userspace programs")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Acked-by: Paul E. McKenney &lt;paulmck@kernel.org&gt;
Signed-off-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-5.16-3' of git://github.com/cminyard/linux-ipmi</title>
<updated>2021-12-22T18:11:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-12-22T18:11:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=074004058094a07f784c8162153fa44c1e05596b'/>
<id>074004058094a07f784c8162153fa44c1e05596b</id>
<content type='text'>
Pull IPMI fixes from Corey Minyard:
 "Fix some IPMI crashes

  Some crash fixes have come in dealing with various error handling
  issues. They have sat in next for 5 days or more without issue, and
  they are fairly critical"

* tag 'for-linus-5.16-3' of git://github.com/cminyard/linux-ipmi:
  ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module
  ipmi: fix initialization when workqueue allocation fails
  ipmi: bail out if init_srcu_struct fails
  ipmi: ssif: initialize ssif_info-&gt;client early
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull IPMI fixes from Corey Minyard:
 "Fix some IPMI crashes

  Some crash fixes have come in dealing with various error handling
  issues. They have sat in next for 5 days or more without issue, and
  they are fairly critical"

* tag 'for-linus-5.16-3' of git://github.com/cminyard/linux-ipmi:
  ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module
  ipmi: fix initialization when workqueue allocation fails
  ipmi: bail out if init_srcu_struct fails
  ipmi: ssif: initialize ssif_info-&gt;client early
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmi: Fix UAF when uninstall ipmi_si and ipmi_msghandler module</title>
<updated>2021-12-21T14:04:42+00:00</updated>
<author>
<name>Wu Bo</name>
<email>wubo40@huawei.com</email>
</author>
<published>2021-12-21T07:00:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ffb76a86f8096a8206be03b14adda6092e18e275'/>
<id>ffb76a86f8096a8206be03b14adda6092e18e275</id>
<content type='text'>
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.
    -&gt;ipmi_unregister_smi()
        -&gt; ipmi_bmc_unregister()
            -&gt; __ipmi_bmc_unregister()
                -&gt; kref_put(&amp;bmc-&gt;usecount, cleanup_bmc_device);
                    -&gt; schedule_work(&amp;bmc-&gt;remove_work);

T2: rmmod ipmi_msghandler.
    ipmi_msghander module uninstalled, and the module space
    will be freed.

T3: bmc-&gt;remove_work doing cleanup the bmc resource.
    -&gt; cleanup_bmc_work()
        -&gt; platform_device_unregister(&amp;bmc-&gt;pdev);
            -&gt; platform_device_del(pdev);
                -&gt; device_del(&amp;pdev-&gt;dev);
                    -&gt; kobject_uevent(&amp;dev-&gt;kobj, KOBJ_REMOVE);
                        -&gt; kobject_uevent_env()
                            -&gt; dev_uevent()
                                -&gt; if (dev-&gt;type &amp;&amp; dev-&gt;type-&gt;name)

   'dev-&gt;type'(bmc_device_type) pointer space has freed when uninstall
    ipmi_msghander module, 'dev-&gt;type-&gt;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-&gt;pdev.id; /* Unregister overwrites id */
2915
2916         msleep(3000);   &lt;---
2917         platform_device_unregister(&amp;bmc-&gt;pdev);
2918         ida_simple_remove(&amp;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 &lt;wubo40@huawei.com&gt;
Message-Id: &lt;1640070034-56671-1-git-send-email-wubo40@huawei.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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.
    -&gt;ipmi_unregister_smi()
        -&gt; ipmi_bmc_unregister()
            -&gt; __ipmi_bmc_unregister()
                -&gt; kref_put(&amp;bmc-&gt;usecount, cleanup_bmc_device);
                    -&gt; schedule_work(&amp;bmc-&gt;remove_work);

T2: rmmod ipmi_msghandler.
    ipmi_msghander module uninstalled, and the module space
    will be freed.

T3: bmc-&gt;remove_work doing cleanup the bmc resource.
    -&gt; cleanup_bmc_work()
        -&gt; platform_device_unregister(&amp;bmc-&gt;pdev);
            -&gt; platform_device_del(pdev);
                -&gt; device_del(&amp;pdev-&gt;dev);
                    -&gt; kobject_uevent(&amp;dev-&gt;kobj, KOBJ_REMOVE);
                        -&gt; kobject_uevent_env()
                            -&gt; dev_uevent()
                                -&gt; if (dev-&gt;type &amp;&amp; dev-&gt;type-&gt;name)

   'dev-&gt;type'(bmc_device_type) pointer space has freed when uninstall
    ipmi_msghander module, 'dev-&gt;type-&gt;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-&gt;pdev.id; /* Unregister overwrites id */
2915
2916         msleep(3000);   &lt;---
2917         platform_device_unregister(&amp;bmc-&gt;pdev);
2918         ida_simple_remove(&amp;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 &lt;wubo40@huawei.com&gt;
Message-Id: &lt;1640070034-56671-1-git-send-email-wubo40@huawei.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmi: fix initialization when workqueue allocation fails</title>
<updated>2021-12-17T20:39:03+00:00</updated>
<author>
<name>Thadeu Lima de Souza Cascardo</name>
<email>cascardo@canonical.com</email>
</author>
<published>2021-12-17T15:44:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=75d70d76cb7b927cace2cb34265d68ebb3306b13'/>
<id>75d70d76cb7b927cace2cb34265d68ebb3306b13</id>
<content type='text'>
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 &lt;cascardo@canonical.com&gt;
Cc: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Ioanna Alifieraki &lt;ioanna-maria.alifieraki@canonical.com&gt;
Cc: stable@vger.kernel.org
Message-Id: &lt;20211217154410.1228673-2-cascardo@canonical.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;cascardo@canonical.com&gt;
Cc: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: Ioanna Alifieraki &lt;ioanna-maria.alifieraki@canonical.com&gt;
Cc: stable@vger.kernel.org
Message-Id: &lt;20211217154410.1228673-2-cascardo@canonical.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmi: bail out if init_srcu_struct fails</title>
<updated>2021-12-17T20:39:03+00:00</updated>
<author>
<name>Thadeu Lima de Souza Cascardo</name>
<email>cascardo@canonical.com</email>
</author>
<published>2021-12-17T15:44:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2b5160b12091285c5aca45980f100a9294af7b04'/>
<id>2b5160b12091285c5aca45980f100a9294af7b04</id>
<content type='text'>
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 &lt;cascardo@canonical.com&gt;
Cc: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: stable@vger.kernel.org
Message-Id: &lt;20211217154410.1228673-1-cascardo@canonical.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;cascardo@canonical.com&gt;
Cc: Corey Minyard &lt;cminyard@mvista.com&gt;
Cc: stable@vger.kernel.org
Message-Id: &lt;20211217154410.1228673-1-cascardo@canonical.com&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmi: ssif: initialize ssif_info-&gt;client early</title>
<updated>2021-12-08T13:13:37+00:00</updated>
<author>
<name>Mian Yousaf Kaukab</name>
<email>ykaukab@suse.de</email>
</author>
<published>2021-12-08T09:32:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=34f35f8f14bc406efc06ee4ff73202c6fd245d15'/>
<id>34f35f8f14bc406efc06ee4ff73202c6fd245d15</id>
<content type='text'>
During probe ssif_info-&gt;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-&gt;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 &lt;tiwai@suse.de&gt;
Signed-off-by: Mian Yousaf Kaukab &lt;ykaukab@suse.de&gt;
Message-Id: &lt;20211208093239.4432-1-ykaukab@suse.de&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
During probe ssif_info-&gt;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-&gt;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 &lt;tiwai@suse.de&gt;
Signed-off-by: Mian Yousaf Kaukab &lt;ykaukab@suse.de&gt;
Message-Id: &lt;20211208093239.4432-1-ykaukab@suse.de&gt;
Signed-off-by: Corey Minyard &lt;cminyard@mvista.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-5.16/parisc-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux</title>
<updated>2021-12-05T20:58:18+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-12-05T20:58:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=268ba095371cb28841bd9bd7f61c73290104a064'/>
<id>268ba095371cb28841bd9bd7f61c73290104a064</id>
<content type='text'>
Pull parisc fixes from Helge Deller:
 "Some bug and warning fixes:

   - Fix "make install" to use debians "installkernel" script which is
     now in /usr/sbin

   - Fix the bindeb-pkg make target by giving the correct KBUILD_IMAGE
     file name

   - Fix compiler warnings by annotating parisc agp init functions with
     __init

   - Fix timekeeping on SMP machines with dual-core CPUs

   - Enable some more config options in the 64-bit defconfig"

* tag 'for-5.16/parisc-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Mark cr16 CPU clocksource unstable on all SMP machines
  parisc: Fix "make install" on newer debian releases
  parisc/agp: Annotate parisc agp init functions with __init
  parisc: Enable sata sil, audit and usb support on 64-bit defconfig
  parisc: Fix KBUILD_IMAGE for self-extracting kernel
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull parisc fixes from Helge Deller:
 "Some bug and warning fixes:

   - Fix "make install" to use debians "installkernel" script which is
     now in /usr/sbin

   - Fix the bindeb-pkg make target by giving the correct KBUILD_IMAGE
     file name

   - Fix compiler warnings by annotating parisc agp init functions with
     __init

   - Fix timekeeping on SMP machines with dual-core CPUs

   - Enable some more config options in the 64-bit defconfig"

* tag 'for-5.16/parisc-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Mark cr16 CPU clocksource unstable on all SMP machines
  parisc: Fix "make install" on newer debian releases
  parisc/agp: Annotate parisc agp init functions with __init
  parisc: Enable sata sil, audit and usb support on 64-bit defconfig
  parisc: Fix KBUILD_IMAGE for self-extracting kernel
</pre>
</div>
</content>
</entry>
<entry>
<title>parisc/agp: Annotate parisc agp init functions with __init</title>
<updated>2021-11-30T20:49:33+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2021-11-26T15:45:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8d88382b7436551a9ebb78475c546b670790cbf6'/>
<id>8d88382b7436551a9ebb78475c546b670790cbf6</id>
<content type='text'>
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
