<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include, branch v5.15.63</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ALSA: control: Use deferred fasync helper</title>
<updated>2022-08-25T09:40:44+00:00</updated>
<author>
<name>Takashi Iwai</name>
<email>tiwai@suse.de</email>
</author>
<published>2022-07-28T12:59:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3895d353f45a9389537ee8ffaffee306bff5992f'/>
<id>3895d353f45a9389537ee8ffaffee306bff5992f</id>
<content type='text'>
[ Upstream commit 4a971e84a7ae10a38d875cd2d4e487c8d1682ca3 ]

For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from the control API.  Note
that it's merely a workaround.

Another note: although we haven't received reports about the deadlock
with the control API, the deadlock is still potentially possible, and
it's better to align the behavior with other core APIs (PCM and
timer); so let's move altogether.

Link: https://lore.kernel.org/r/20220728125945.29533-5-tiwai@suse.de
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 4a971e84a7ae10a38d875cd2d4e487c8d1682ca3 ]

For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from the control API.  Note
that it's merely a workaround.

Another note: although we haven't received reports about the deadlock
with the control API, the deadlock is still potentially possible, and
it's better to align the behavior with other core APIs (PCM and
timer); so let's move altogether.

Link: https://lore.kernel.org/r/20220728125945.29533-5-tiwai@suse.de
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ALSA: core: Add async signal helpers</title>
<updated>2022-08-25T09:40:44+00:00</updated>
<author>
<name>Takashi Iwai</name>
<email>tiwai@suse.de</email>
</author>
<published>2022-07-28T12:59:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=60110fd2662368425271c495044ef31cc013a2db'/>
<id>60110fd2662368425271c495044ef31cc013a2db</id>
<content type='text'>
[ Upstream commit ef34a0ae7a2654bc9e58675e36898217fb2799d8 ]

Currently the call of kill_fasync() from an interrupt handler might
lead to potential spin deadlocks, as spotted by syzkaller.
Unfortunately, it's not so trivial to fix this lock chain as it's
involved with the tasklist_lock that is touched in allover places.

As a temporary workaround, this patch provides the way to defer the
async signal notification in a work.  The new helper functions,
snd_fasync_helper() and snd_kill_faync() are replacements for
fasync_helper() and kill_fasync(), respectively.  In addition,
snd_fasync_free() needs to be called at the destructor of the relevant
file object.

Link: https://lore.kernel.org/r/20220728125945.29533-2-tiwai@suse.de
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ef34a0ae7a2654bc9e58675e36898217fb2799d8 ]

Currently the call of kill_fasync() from an interrupt handler might
lead to potential spin deadlocks, as spotted by syzkaller.
Unfortunately, it's not so trivial to fix this lock chain as it's
involved with the tasklist_lock that is touched in allover places.

As a temporary workaround, this patch provides the way to defer the
async signal notification in a work.  The new helper functions,
snd_fasync_helper() and snd_kill_faync() are replacements for
fasync_helper() and kill_fasync(), respectively.  In addition,
snd_fasync_free() needs to be called at the destructor of the relevant
file object.

Link: https://lore.kernel.org/r/20220728125945.29533-2-tiwai@suse.de
Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>watchdog: export lockup_detector_reconfigure</title>
<updated>2022-08-25T09:40:43+00:00</updated>
<author>
<name>Laurent Dufour</name>
<email>ldufour@linux.ibm.com</email>
</author>
<published>2022-07-13T15:47:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6568e52b281c604e5e7cddc2797b06c9dcc282d0'/>
<id>6568e52b281c604e5e7cddc2797b06c9dcc282d0</id>
<content type='text'>
[ Upstream commit 7c56a8733d0a2a4be2438a7512566e5ce552fccf ]

In some circumstances it may be interesting to reconfigure the watchdog
from inside the kernel.

On PowerPC, this may helpful before and after a LPAR migration (LPM) is
initiated, because it implies some latencies, watchdog, and especially NMI
watchdog is expected to be triggered during this operation. Reconfiguring
the watchdog with a factor, would prevent it to happen too frequently
during LPM.

Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and
create a new function lockup_detector_reconfigure() calling
__lockup_detector_reconfigure() under the protection of watchdog_mutex.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.ibm.com&gt;
[mpe: Squash in build fix from Laurent, reported by Sachin]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7c56a8733d0a2a4be2438a7512566e5ce552fccf ]

In some circumstances it may be interesting to reconfigure the watchdog
from inside the kernel.

On PowerPC, this may helpful before and after a LPAR migration (LPM) is
initiated, because it implies some latencies, watchdog, and especially NMI
watchdog is expected to be triggered during this operation. Reconfiguring
the watchdog with a factor, would prevent it to happen too frequently
during LPM.

Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and
create a new function lockup_detector_reconfigure() calling
__lockup_detector_reconfigure() under the protection of watchdog_mutex.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.ibm.com&gt;
[mpe: Squash in build fix from Laurent, reported by Sachin]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>iommu/io-pgtable-arm-v7s: Add a quirk to allow pgtable PA up to 35bit</title>
<updated>2022-08-25T09:40:41+00:00</updated>
<author>
<name>Yunfei Wang</name>
<email>yf.wang@mediatek.com</email>
</author>
<published>2022-06-30T09:29:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2097c7835162619dd5e584537967f7f88e990435'/>
<id>2097c7835162619dd5e584537967f7f88e990435</id>
<content type='text'>
[ Upstream commit bfdd231374181254742c5e2faef0bef2d30c0ee4 ]

Single memory zone feature will remove ZONE_DMA32 and ZONE_DMA and
cause pgtable PA size larger than 32bit.

Since Mediatek IOMMU hardware support at most 35bit PA in pgtable,
so add a quirk to allow the PA of pgtables support up to bit35.

Signed-off-by: Ning Li &lt;ning.li@mediatek.com&gt;
Signed-off-by: Yunfei Wang &lt;yf.wang@mediatek.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20220630092927.24925-2-yf.wang@mediatek.com
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bfdd231374181254742c5e2faef0bef2d30c0ee4 ]

Single memory zone feature will remove ZONE_DMA32 and ZONE_DMA and
cause pgtable PA size larger than 32bit.

Since Mediatek IOMMU hardware support at most 35bit PA in pgtable,
so add a quirk to allow the PA of pgtables support up to bit35.

Signed-off-by: Ning Li &lt;ning.li@mediatek.com&gt;
Signed-off-by: Yunfei Wang &lt;yf.wang@mediatek.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20220630092927.24925-2-yf.wang@mediatek.com
Signed-off-by: Joerg Roedel &lt;jroedel@suse.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>uacce: Handle parent device removal or parent driver module rmmod</title>
<updated>2022-08-25T09:40:34+00:00</updated>
<author>
<name>Jean-Philippe Brucker</name>
<email>jean-philippe@linaro.org</email>
</author>
<published>2022-07-01T03:48:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=50de5045815e4c3a5b261187c1497dad517f3420'/>
<id>50de5045815e4c3a5b261187c1497dad517f3420</id>
<content type='text'>
[ Upstream commit 80fc671bcc0173836e9032b0c698ea74c13b9d7c ]

The uacce driver must deal with a possible removal of the parent device
or parent driver module rmmod at any time.

Although uacce_remove(), called on device removal and on driver unbind,
prevents future use of the uacce fops by removing the cdev, fops that
were called before that point may still be running.

Serialize uacce_fops_open() and uacce_remove() with uacce-&gt;mutex.
Serialize other fops against uacce_remove() with q-&gt;mutex.
Since we need to protect uacce_fops_poll() which gets called on the fast
path, replace uacce-&gt;queues_lock with q-&gt;mutex to improve scalability.
The other fops are only used during setup.

uacce_queue_is_valid(), checked under q-&gt;mutex or uacce-&gt;mutex, denotes
whether uacce_remove() has disabled all queues. If that is the case,
don't go any further since the parent device is being removed and
uacce-&gt;ops should not be called anymore.

Reported-by: Yang Shen &lt;shenyang39@huawei.com&gt;
Signed-off-by: Zhangfei Gao &lt;zhangfei.gao@linaro.org&gt;
Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Link: https://lore.kernel.org/r/20220701034843.7502-1-zhangfei.gao@linaro.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 80fc671bcc0173836e9032b0c698ea74c13b9d7c ]

The uacce driver must deal with a possible removal of the parent device
or parent driver module rmmod at any time.

Although uacce_remove(), called on device removal and on driver unbind,
prevents future use of the uacce fops by removing the cdev, fops that
were called before that point may still be running.

Serialize uacce_fops_open() and uacce_remove() with uacce-&gt;mutex.
Serialize other fops against uacce_remove() with q-&gt;mutex.
Since we need to protect uacce_fops_poll() which gets called on the fast
path, replace uacce-&gt;queues_lock with q-&gt;mutex to improve scalability.
The other fops are only used during setup.

uacce_queue_is_valid(), checked under q-&gt;mutex or uacce-&gt;mutex, denotes
whether uacce_remove() has disabled all queues. If that is the case,
don't go any further since the parent device is being removed and
uacce-&gt;ops should not be called anymore.

Reported-by: Yang Shen &lt;shenyang39@huawei.com&gt;
Signed-off-by: Zhangfei Gao &lt;zhangfei.gao@linaro.org&gt;
Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Link: https://lore.kernel.org/r/20220701034843.7502-1-zhangfei.gao@linaro.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>SUNRPC: Fix xdr_encode_bool()</title>
<updated>2022-08-25T09:40:05+00:00</updated>
<author>
<name>Chuck Lever</name>
<email>chuck.lever@oracle.com</email>
</author>
<published>2022-07-19T13:18:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d3c262f584dff64e6fe963acdbed0acdf165da63'/>
<id>d3c262f584dff64e6fe963acdbed0acdf165da63</id>
<content type='text'>
commit c770f31d8f580ed4b965c64f924ec1cc50e41734 upstream.

I discovered that xdr_encode_bool() was returning the same address
that was passed in the @p parameter. The documenting comment states
that the intent is to return the address of the next buffer
location, just like the other "xdr_encode_*" helpers.

The result was the encoded results of NFSv3 PATHCONF operations were
not formed correctly.

Fixes: ded04a587f6c ("NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream")
Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Reviewed-by: Jeff Layton &lt;jlayton@kernel.org&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 c770f31d8f580ed4b965c64f924ec1cc50e41734 upstream.

I discovered that xdr_encode_bool() was returning the same address
that was passed in the @p parameter. The documenting comment states
that the intent is to return the address of the next buffer
location, just like the other "xdr_encode_*" helpers.

The result was the encoded results of NFSv3 PATHCONF operations were
not formed correctly.

Fixes: ded04a587f6c ("NFSD: Update the NFSv3 PATHCONF3res encoder to use struct xdr_stream")
Signed-off-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Reviewed-by: Jeff Layton &lt;jlayton@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>BPF: Fix potential bad pointer dereference in bpf_sys_bpf()</title>
<updated>2022-08-25T09:40:02+00:00</updated>
<author>
<name>Jinghao Jia</name>
<email>jinghao@linux.ibm.com</email>
</author>
<published>2022-07-29T20:17:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=41fd6cc88aaf7058b9dfc9c7a09cc80f99c8c830'/>
<id>41fd6cc88aaf7058b9dfc9c7a09cc80f99c8c830</id>
<content type='text'>
commit e2dcac2f58f5a95ab092d1da237ffdc0da1832cf upstream.

The bpf_sys_bpf() helper function allows an eBPF program to load another
eBPF program from within the kernel. In this case the argument union
bpf_attr pointer (as well as the insns and license pointers inside) is a
kernel address instead of a userspace address (which is the case of a
usual bpf() syscall). To make the memory copying process in the syscall
work in both cases, bpfptr_t was introduced to wrap around the pointer
and distinguish its origin. Specifically, when copying memory contents
from a bpfptr_t, a copy_from_user() is performed in case of a userspace
address and a memcpy() is performed for a kernel address.

This can lead to problems because the in-kernel pointer is never checked
for validity. The problem happens when an eBPF syscall program tries to
call bpf_sys_bpf() to load a program but provides a bad insns pointer --
say 0xdeadbeef -- in the bpf_attr union. The helper calls __sys_bpf()
which would then call bpf_prog_load() to load the program.
bpf_prog_load() is responsible for copying the eBPF instructions to the
newly allocated memory for the program; it creates a kernel bpfptr_t for
insns and invokes copy_from_bpfptr(). Internally, all bpfptr_t
operations are backed by the corresponding sockptr_t operations, which
performs direct memcpy() on kernel pointers for copy_from/strncpy_from
operations. Therefore, the code is always happy to dereference the bad
pointer to trigger a un-handle-able page fault and in turn an oops.
However, this is not supposed to happen because at that point the eBPF
program is already verified and should not cause a memory error.

Sample KASAN trace:

[   25.685056][  T228] ==================================================================
[   25.685680][  T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30
[   25.686210][  T228] Read of size 80 at addr 00000000deadbeef by task poc/228
[   25.686732][  T228]
[   25.686893][  T228] CPU: 3 PID: 228 Comm: poc Not tainted 5.19.0-rc7 #7
[   25.687375][  T228] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014
[   25.687991][  T228] Call Trace:
[   25.688223][  T228]  &lt;TASK&gt;
[   25.688429][  T228]  dump_stack_lvl+0x73/0x9e
[   25.688747][  T228]  print_report+0xea/0x200
[   25.689061][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.689401][  T228]  ? _printk+0x54/0x6e
[   25.689693][  T228]  ? _raw_spin_lock_irqsave+0x70/0xd0
[   25.690071][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.690412][  T228]  kasan_report+0xb5/0xe0
[   25.690716][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.691059][  T228]  kasan_check_range+0x2bd/0x2e0
[   25.691405][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.691734][  T228]  memcpy+0x25/0x60
[   25.692000][  T228]  copy_from_bpfptr+0x21/0x30
[   25.692328][  T228]  bpf_prog_load+0x604/0x9e0
[   25.692653][  T228]  ? cap_capable+0xb4/0xe0
[   25.692956][  T228]  ? security_capable+0x4f/0x70
[   25.693324][  T228]  __sys_bpf+0x3af/0x580
[   25.693635][  T228]  bpf_sys_bpf+0x45/0x240
[   25.693937][  T228]  bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd
[   25.694394][  T228]  bpf_prog_run_pin_on_cpu+0x2f/0xb0
[   25.694756][  T228]  bpf_prog_test_run_syscall+0x146/0x1c0
[   25.695144][  T228]  bpf_prog_test_run+0x172/0x190
[   25.695487][  T228]  __sys_bpf+0x2c5/0x580
[   25.695776][  T228]  __x64_sys_bpf+0x3a/0x50
[   25.696084][  T228]  do_syscall_64+0x60/0x90
[   25.696393][  T228]  ? fpregs_assert_state_consistent+0x50/0x60
[   25.696815][  T228]  ? exit_to_user_mode_prepare+0x36/0xa0
[   25.697202][  T228]  ? syscall_exit_to_user_mode+0x20/0x40
[   25.697586][  T228]  ? do_syscall_64+0x6e/0x90
[   25.697899][  T228]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   25.698312][  T228] RIP: 0033:0x7f6d543fb759
[   25.698624][  T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 a6 0e 00 f7 d8 64 89 01 48
[   25.699946][  T228] RSP: 002b:00007ffc3df78468 EFLAGS: 00000287 ORIG_RAX: 0000000000000141
[   25.700526][  T228] RAX: ffffffffffffffda RBX: 00007ffc3df78628 RCX: 00007f6d543fb759
[   25.701071][  T228] RDX: 0000000000000090 RSI: 00007ffc3df78478 RDI: 000000000000000a
[   25.701636][  T228] RBP: 00007ffc3df78510 R08: 0000000000000000 R09: 0000000000300000
[   25.702191][  T228] R10: 0000000000000005 R11: 0000000000000287 R12: 0000000000000000
[   25.702736][  T228] R13: 00007ffc3df78638 R14: 000055a1584aca68 R15: 00007f6d5456a000
[   25.703282][  T228]  &lt;/TASK&gt;
[   25.703490][  T228] ==================================================================
[   25.704050][  T228] Disabling lock debugging due to kernel taint

Update copy_from_bpfptr() and strncpy_from_bpfptr() so that:
 - for a kernel pointer, it uses the safe copy_from_kernel_nofault() and
   strncpy_from_kernel_nofault() functions.
 - for a userspace pointer, it performs copy_from_user() and
   strncpy_from_user().

Fixes: af2ac3e13e45 ("bpf: Prepare bpf syscall to be used from kernel and user space.")
Link: https://lore.kernel.org/bpf/20220727132905.45166-1-jinghao@linux.ibm.com/
Signed-off-by: Jinghao Jia &lt;jinghao@linux.ibm.com&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/r/20220729201713.88688-1-jinghao@linux.ibm.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&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 e2dcac2f58f5a95ab092d1da237ffdc0da1832cf upstream.

The bpf_sys_bpf() helper function allows an eBPF program to load another
eBPF program from within the kernel. In this case the argument union
bpf_attr pointer (as well as the insns and license pointers inside) is a
kernel address instead of a userspace address (which is the case of a
usual bpf() syscall). To make the memory copying process in the syscall
work in both cases, bpfptr_t was introduced to wrap around the pointer
and distinguish its origin. Specifically, when copying memory contents
from a bpfptr_t, a copy_from_user() is performed in case of a userspace
address and a memcpy() is performed for a kernel address.

This can lead to problems because the in-kernel pointer is never checked
for validity. The problem happens when an eBPF syscall program tries to
call bpf_sys_bpf() to load a program but provides a bad insns pointer --
say 0xdeadbeef -- in the bpf_attr union. The helper calls __sys_bpf()
which would then call bpf_prog_load() to load the program.
bpf_prog_load() is responsible for copying the eBPF instructions to the
newly allocated memory for the program; it creates a kernel bpfptr_t for
insns and invokes copy_from_bpfptr(). Internally, all bpfptr_t
operations are backed by the corresponding sockptr_t operations, which
performs direct memcpy() on kernel pointers for copy_from/strncpy_from
operations. Therefore, the code is always happy to dereference the bad
pointer to trigger a un-handle-able page fault and in turn an oops.
However, this is not supposed to happen because at that point the eBPF
program is already verified and should not cause a memory error.

Sample KASAN trace:

[   25.685056][  T228] ==================================================================
[   25.685680][  T228] BUG: KASAN: user-memory-access in copy_from_bpfptr+0x21/0x30
[   25.686210][  T228] Read of size 80 at addr 00000000deadbeef by task poc/228
[   25.686732][  T228]
[   25.686893][  T228] CPU: 3 PID: 228 Comm: poc Not tainted 5.19.0-rc7 #7
[   25.687375][  T228] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014
[   25.687991][  T228] Call Trace:
[   25.688223][  T228]  &lt;TASK&gt;
[   25.688429][  T228]  dump_stack_lvl+0x73/0x9e
[   25.688747][  T228]  print_report+0xea/0x200
[   25.689061][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.689401][  T228]  ? _printk+0x54/0x6e
[   25.689693][  T228]  ? _raw_spin_lock_irqsave+0x70/0xd0
[   25.690071][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.690412][  T228]  kasan_report+0xb5/0xe0
[   25.690716][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.691059][  T228]  kasan_check_range+0x2bd/0x2e0
[   25.691405][  T228]  ? copy_from_bpfptr+0x21/0x30
[   25.691734][  T228]  memcpy+0x25/0x60
[   25.692000][  T228]  copy_from_bpfptr+0x21/0x30
[   25.692328][  T228]  bpf_prog_load+0x604/0x9e0
[   25.692653][  T228]  ? cap_capable+0xb4/0xe0
[   25.692956][  T228]  ? security_capable+0x4f/0x70
[   25.693324][  T228]  __sys_bpf+0x3af/0x580
[   25.693635][  T228]  bpf_sys_bpf+0x45/0x240
[   25.693937][  T228]  bpf_prog_f0ec79a5a3caca46_bpf_func1+0xa2/0xbd
[   25.694394][  T228]  bpf_prog_run_pin_on_cpu+0x2f/0xb0
[   25.694756][  T228]  bpf_prog_test_run_syscall+0x146/0x1c0
[   25.695144][  T228]  bpf_prog_test_run+0x172/0x190
[   25.695487][  T228]  __sys_bpf+0x2c5/0x580
[   25.695776][  T228]  __x64_sys_bpf+0x3a/0x50
[   25.696084][  T228]  do_syscall_64+0x60/0x90
[   25.696393][  T228]  ? fpregs_assert_state_consistent+0x50/0x60
[   25.696815][  T228]  ? exit_to_user_mode_prepare+0x36/0xa0
[   25.697202][  T228]  ? syscall_exit_to_user_mode+0x20/0x40
[   25.697586][  T228]  ? do_syscall_64+0x6e/0x90
[   25.697899][  T228]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[   25.698312][  T228] RIP: 0033:0x7f6d543fb759
[   25.698624][  T228] Code: 08 5b 89 e8 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 a6 0e 00 f7 d8 64 89 01 48
[   25.699946][  T228] RSP: 002b:00007ffc3df78468 EFLAGS: 00000287 ORIG_RAX: 0000000000000141
[   25.700526][  T228] RAX: ffffffffffffffda RBX: 00007ffc3df78628 RCX: 00007f6d543fb759
[   25.701071][  T228] RDX: 0000000000000090 RSI: 00007ffc3df78478 RDI: 000000000000000a
[   25.701636][  T228] RBP: 00007ffc3df78510 R08: 0000000000000000 R09: 0000000000300000
[   25.702191][  T228] R10: 0000000000000005 R11: 0000000000000287 R12: 0000000000000000
[   25.702736][  T228] R13: 00007ffc3df78638 R14: 000055a1584aca68 R15: 00007f6d5456a000
[   25.703282][  T228]  &lt;/TASK&gt;
[   25.703490][  T228] ==================================================================
[   25.704050][  T228] Disabling lock debugging due to kernel taint

Update copy_from_bpfptr() and strncpy_from_bpfptr() so that:
 - for a kernel pointer, it uses the safe copy_from_kernel_nofault() and
   strncpy_from_kernel_nofault() functions.
 - for a userspace pointer, it performs copy_from_user() and
   strncpy_from_user().

Fixes: af2ac3e13e45 ("bpf: Prepare bpf syscall to be used from kernel and user space.")
Link: https://lore.kernel.org/bpf/20220727132905.45166-1-jinghao@linux.ibm.com/
Signed-off-by: Jinghao Jia &lt;jinghao@linux.ibm.com&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/r/20220729201713.88688-1-jinghao@linux.ibm.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/atomic: Make test_and_*_bit() ordered on failure</title>
<updated>2022-08-25T09:39:54+00:00</updated>
<author>
<name>Hector Martin</name>
<email>marcan@marcan.st</email>
</author>
<published>2022-08-16T07:03:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1b7e0482abd03da8e09773f56db31aba9e77ef17'/>
<id>1b7e0482abd03da8e09773f56db31aba9e77ef17</id>
<content type='text'>
commit 415d832497098030241605c52ea83d4e2cfa7879 upstream.

These operations are documented as always ordered in
include/asm-generic/bitops/instrumented-atomic.h, and producer-consumer
type use cases where one side needs to ensure a flag is left pending
after some shared data was updated rely on this ordering, even in the
failure case.

This is the case with the workqueue code, which currently suffers from a
reproducible ordering violation on Apple M1 platforms (which are
notoriously out-of-order) that ends up causing the TTY layer to fail to
deliver data to userspace properly under the right conditions.  This
change fixes that bug.

Change the documentation to restrict the "no order on failure" story to
the _lock() variant (for which it makes sense), and remove the
early-exit from the generic implementation, which is what causes the
missing barrier semantics in that case.  Without this, the remaining
atomic op is fully ordered (including on ARM64 LSE, as of recent
versions of the architecture spec).

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: stable@vger.kernel.org
Fixes: e986a0d6cb36 ("locking/atomics, asm-generic/bitops/atomic.h: Rewrite using atomic_*() APIs")
Fixes: 61e02392d3c7 ("locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()")
Signed-off-by: Hector Martin &lt;marcan@marcan.st&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&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 415d832497098030241605c52ea83d4e2cfa7879 upstream.

These operations are documented as always ordered in
include/asm-generic/bitops/instrumented-atomic.h, and producer-consumer
type use cases where one side needs to ensure a flag is left pending
after some shared data was updated rely on this ordering, even in the
failure case.

This is the case with the workqueue code, which currently suffers from a
reproducible ordering violation on Apple M1 platforms (which are
notoriously out-of-order) that ends up causing the TTY layer to fail to
deliver data to userspace properly under the right conditions.  This
change fixes that bug.

Change the documentation to restrict the "no order on failure" story to
the _lock() variant (for which it makes sense), and remove the
early-exit from the generic implementation, which is what causes the
missing barrier semantics in that case.  Without this, the remaining
atomic op is fully ordered (including on ARM64 LSE, as of recent
versions of the architecture spec).

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: stable@vger.kernel.org
Fixes: e986a0d6cb36 ("locking/atomics, asm-generic/bitops/atomic.h: Rewrite using atomic_*() APIs")
Fixes: 61e02392d3c7 ("locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()")
Signed-off-by: Hector Martin &lt;marcan@marcan.st&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/perf: Avoid -Warray-bounds warning for __rel_loc macro</title>
<updated>2022-08-17T12:24:30+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2022-01-25T22:00:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3cfd07084b7ec3751a31c2373176c9b17889ae65'/>
<id>3cfd07084b7ec3751a31c2373176c9b17889ae65</id>
<content type='text'>
commit c6d777acdf8f62d4ebaef0e5c6cd8fedbd6e8546 upstream.

As done for trace_events.h, also fix the __rel_loc macro in perf.h,
which silences the -Warray-bounds warning:

In file included from ./include/linux/string.h:253,
                 from ./include/linux/bitmap.h:11,
                 from ./include/linux/cpumask.h:12,
                 from ./include/linux/mm_types_task.h:14,
                 from ./include/linux/mm_types.h:5,
                 from ./include/linux/buildid.h:5,
                 from ./include/linux/module.h:14,
                 from samples/trace_events/trace-events-sample.c:2:
In function '__fortify_strcpy',
    inlined from 'perf_trace_foo_rel_loc' at samples/trace_events/./trace-events-sample.h:519:1:
./include/linux/fortify-string.h:47:33: warning: '__builtin_strcpy' offset 12 is out of the bounds [
0, 4] [-Warray-bounds]
   47 | #define __underlying_strcpy     __builtin_strcpy
      |                                 ^
./include/linux/fortify-string.h:445:24: note: in expansion of macro '__underlying_strcpy'
  445 |                 return __underlying_strcpy(p, q);
      |                        ^~~~~~~~~~~~~~~~~~~

Also make __data struct member a proper flexible array to avoid future
problems.

Link: https://lkml.kernel.org/r/20220125220037.2738923-1-keescook@chromium.org

Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Fixes: 55de2c0b5610c ("tracing: Add '__rel_loc' using trace event macros")
Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&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 c6d777acdf8f62d4ebaef0e5c6cd8fedbd6e8546 upstream.

As done for trace_events.h, also fix the __rel_loc macro in perf.h,
which silences the -Warray-bounds warning:

In file included from ./include/linux/string.h:253,
                 from ./include/linux/bitmap.h:11,
                 from ./include/linux/cpumask.h:12,
                 from ./include/linux/mm_types_task.h:14,
                 from ./include/linux/mm_types.h:5,
                 from ./include/linux/buildid.h:5,
                 from ./include/linux/module.h:14,
                 from samples/trace_events/trace-events-sample.c:2:
In function '__fortify_strcpy',
    inlined from 'perf_trace_foo_rel_loc' at samples/trace_events/./trace-events-sample.h:519:1:
./include/linux/fortify-string.h:47:33: warning: '__builtin_strcpy' offset 12 is out of the bounds [
0, 4] [-Warray-bounds]
   47 | #define __underlying_strcpy     __builtin_strcpy
      |                                 ^
./include/linux/fortify-string.h:445:24: note: in expansion of macro '__underlying_strcpy'
  445 |                 return __underlying_strcpy(p, q);
      |                        ^~~~~~~~~~~~~~~~~~~

Also make __data struct member a proper flexible array to avoid future
problems.

Link: https://lkml.kernel.org/r/20220125220037.2738923-1-keescook@chromium.org

Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Fixes: 55de2c0b5610c ("tracing: Add '__rel_loc' using trace event macros")
Reported-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Use a struct alignof to determine trace event field alignment</title>
<updated>2022-08-17T12:24:29+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-07-31T05:59:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f467478d15faa46471981ff078e6f7818a52cae5'/>
<id>f467478d15faa46471981ff078e6f7818a52cae5</id>
<content type='text'>
commit 4c3d2f9388d36eb28640a220a6f908328442d873 upstream.

alignof() gives an alignment of types as they would be as standalone
variables. But alignment in structures might be different, and when
building the fields of events, the alignment must be the actual
alignment otherwise the field offsets may not match what they actually
are.

This caused trace-cmd to crash, as libtraceevent did not check if the
field offset was bigger than the event. The write_msr and read_msr
events on 32 bit had their fields incorrect, because it had a u64 field
between two ints. alignof(u64) would give 8, but the u64 field was at a
4 byte alignment.

Define a macro as:

   ALIGN_STRUCTFIELD(type) ((int)(offsetof(struct {char a; type b;}, b)))

which gives the actual alignment of types in a structure.

Link: https://lkml.kernel.org/r/20220731015928.7ab3a154@rorschach.local.home

Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: stable@vger.kernel.org
Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&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 4c3d2f9388d36eb28640a220a6f908328442d873 upstream.

alignof() gives an alignment of types as they would be as standalone
variables. But alignment in structures might be different, and when
building the fields of events, the alignment must be the actual
alignment otherwise the field offsets may not match what they actually
are.

This caused trace-cmd to crash, as libtraceevent did not check if the
field offset was bigger than the event. The write_msr and read_msr
events on 32 bit had their fields incorrect, because it had a u64 field
between two ints. alignof(u64) would give 8, but the u64 field was at a
4 byte alignment.

Define a macro as:

   ALIGN_STRUCTFIELD(type) ((int)(offsetof(struct {char a; type b;}, b)))

which gives the actual alignment of types in a structure.

Link: https://lkml.kernel.org/r/20220731015928.7ab3a154@rorschach.local.home

Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: stable@vger.kernel.org
Fixes: 04ae87a52074e ("ftrace: Rework event_create_dir()")
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
