<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git, branch v5.4.211</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>Linux 5.4.211</title>
<updated>2022-08-25T09:18:40+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2022-08-25T09:18:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=684cc17be897de3b0fd2e5a021a702f68046d9fe'/>
<id>684cc17be897de3b0fd2e5a021a702f68046d9fe</id>
<content type='text'>
Link: https://lore.kernel.org/r/20220823080115.331990024@linuxfoundation.org
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Sudip Mukherjee &lt;sudip.mukherjee@codethink.co.uk&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>
Link: https://lore.kernel.org/r/20220823080115.331990024@linuxfoundation.org
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Sudip Mukherjee &lt;sudip.mukherjee@codethink.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: raid56: don't trust any cached sector in __raid56_parity_recover()</title>
<updated>2022-08-25T09:18:40+00:00</updated>
<author>
<name>Qu Wenruo</name>
<email>wqu@suse.com</email>
</author>
<published>2022-08-20T06:35:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=473f43725bb75a22efbedc03c6cbf77d695b940a'/>
<id>473f43725bb75a22efbedc03c6cbf77d695b940a</id>
<content type='text'>
commit f6065f8edeb25f4a9dfe0b446030ad995a84a088 upstream.

[BUG]
There is a small workload which will always fail with recent kernel:
(A simplified version from btrfs/125 test case)

  mkfs.btrfs -f -m raid5 -d raid5 -b 1G $dev1 $dev2 $dev3
  mount $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xee 0 1M" $mnt/file1
  sync
  umount $mnt
  btrfs dev scan -u $dev3
  mount -o degraded $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xff 0 128M" $mnt/file2
  umount $mnt
  btrfs dev scan
  mount $dev1 $mnt
  btrfs balance start --full-balance $mnt
  umount $mnt

The failure is always failed to read some tree blocks:

  BTRFS info (device dm-4): relocating block group 217710592 flags data|raid5
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  ...

[CAUSE]
With the recently added debug output, we can see all RAID56 operations
related to full stripe 38928384:

  56.1183: raid56_read_partial: full_stripe=38928384 devid=2 type=DATA1 offset=0 opf=0x0 physical=9502720 len=65536
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=16384 opf=0x0 physical=9519104 len=16384
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x0 physical=9551872 len=16384
  56.1187: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=0 opf=0x1 physical=9502720 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=32768 opf=0x1 physical=9535488 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=0 opf=0x1 physical=30474240 len=16384
  56.1189: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=32768 opf=0x1 physical=30507008 len=16384
  56.1218: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x1 physical=9551872 len=16384
  56.1219: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=49152 opf=0x1 physical=30523392 len=16384
  56.2721: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2723: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2724: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2

Before we enter raid56_parity_recover(), we have triggered some metadata
write for the full stripe 38928384, this leads to us to read all the
sectors from disk.

Furthermore, btrfs raid56 write will cache its calculated P/Q sectors to
avoid unnecessary read.

This means, for that full stripe, after any partial write, we will have
stale data, along with P/Q calculated using that stale data.

Thankfully due to patch "btrfs: only write the sectors in the vertical stripe
which has data stripes" we haven't submitted all the corrupted P/Q to disk.

When we really need to recover certain range, aka in
raid56_parity_recover(), we will use the cached rbio, along with its
cached sectors (the full stripe is all cached).

This explains why we have no event raid56_scrub_read_recover()
triggered.

Since we have the cached P/Q which is calculated using the stale data,
the recovered one will just be stale.

In our particular test case, it will always return the same incorrect
metadata, thus causing the same error message "parent transid verify
failed on 39010304 wanted 9 found 7" again and again.

[BTRFS DESTRUCTIVE RMW PROBLEM]

Test case btrfs/125 (and above workload) always has its trouble with
the destructive read-modify-write (RMW) cycle:

        0       32K     64K
Data1:  | Good  | Good  |
Data2:  | Bad   | Bad   |
Parity: | Good  | Good  |

In above case, if we trigger any write into Data1, we will use the bad
data in Data2 to re-generate parity, killing the only chance to recovery
Data2, thus Data2 is lost forever.

This destructive RMW cycle is not specific to btrfs RAID56, but there
are some btrfs specific behaviors making the case even worse:

- Btrfs will cache sectors for unrelated vertical stripes.

  In above example, if we're only writing into 0~32K range, btrfs will
  still read data range (32K ~ 64K) of Data1, and (64K~128K) of Data2.
  This behavior is to cache sectors for later update.

  Incidentally commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio()
  subpage compatible") has a bug which makes RAID56 to never trust the
  cached sectors, thus slightly improve the situation for recovery.

  Unfortunately, follow up fix "btrfs: update stripe_sectors::uptodate in
  steal_rbio" will revert the behavior back to the old one.

- Btrfs raid56 partial write will update all P/Q sectors and cache them

  This means, even if data at (64K ~ 96K) of Data2 is free space, and
  only (96K ~ 128K) of Data2 is really stale data.
  And we write into that (96K ~ 128K), we will update all the parity
  sectors for the full stripe.

  This unnecessary behavior will completely kill the chance of recovery.

  Thankfully, an unrelated optimization "btrfs: only write the sectors
  in the vertical stripe which has data stripes" will prevent
  submitting the write bio for untouched vertical sectors.

  That optimization will keep the on-disk P/Q untouched for a chance for
  later recovery.

[FIX]
Although we have no good way to completely fix the destructive RMW
(unless we go full scrub for each partial write), we can still limit the
damage.

With patch "btrfs: only write the sectors in the vertical stripe which
has data stripes" now we won't really submit the P/Q of unrelated
vertical stripes, so the on-disk P/Q should still be fine.

Now we really need to do is just drop all the cached sectors when doing
recovery.

By this, we have a chance to read the original P/Q from disk, and have a
chance to recover the stale data, while still keep the cache to speed up
regular write path.

In fact, just dropping all the cache for recovery path is good enough to
allow the test case btrfs/125 along with the small script to pass
reliably.

The lack of metadata write after the degraded mount, and forced metadata
COW is saving us this time.

So this patch will fix the behavior by not trust any cache in
__raid56_parity_recover(), to solve the problem while still keep the
cache useful.

But please note that this test pass DOES NOT mean we have solved the
destructive RMW problem, we just do better damage control a little
better.

Related patches:

- btrfs: only write the sectors in the vertical stripe
- d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage compatible")
- btrfs: update stripe_sectors::uptodate in steal_rbio

Acked-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Qu Wenruo &lt;wqu@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.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 f6065f8edeb25f4a9dfe0b446030ad995a84a088 upstream.

[BUG]
There is a small workload which will always fail with recent kernel:
(A simplified version from btrfs/125 test case)

  mkfs.btrfs -f -m raid5 -d raid5 -b 1G $dev1 $dev2 $dev3
  mount $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xee 0 1M" $mnt/file1
  sync
  umount $mnt
  btrfs dev scan -u $dev3
  mount -o degraded $dev1 $mnt
  xfs_io -f -c "pwrite -S 0xff 0 128M" $mnt/file2
  umount $mnt
  btrfs dev scan
  mount $dev1 $mnt
  btrfs balance start --full-balance $mnt
  umount $mnt

The failure is always failed to read some tree blocks:

  BTRFS info (device dm-4): relocating block group 217710592 flags data|raid5
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7
  ...

[CAUSE]
With the recently added debug output, we can see all RAID56 operations
related to full stripe 38928384:

  56.1183: raid56_read_partial: full_stripe=38928384 devid=2 type=DATA1 offset=0 opf=0x0 physical=9502720 len=65536
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=16384 opf=0x0 physical=9519104 len=16384
  56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x0 physical=9551872 len=16384
  56.1187: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=0 opf=0x1 physical=9502720 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=32768 opf=0x1 physical=9535488 len=16384
  56.1188: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=0 opf=0x1 physical=30474240 len=16384
  56.1189: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=32768 opf=0x1 physical=30507008 len=16384
  56.1218: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x1 physical=9551872 len=16384
  56.1219: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=49152 opf=0x1 physical=30523392 len=16384
  56.2721: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2723: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2
  56.2724: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2

Before we enter raid56_parity_recover(), we have triggered some metadata
write for the full stripe 38928384, this leads to us to read all the
sectors from disk.

Furthermore, btrfs raid56 write will cache its calculated P/Q sectors to
avoid unnecessary read.

This means, for that full stripe, after any partial write, we will have
stale data, along with P/Q calculated using that stale data.

Thankfully due to patch "btrfs: only write the sectors in the vertical stripe
which has data stripes" we haven't submitted all the corrupted P/Q to disk.

When we really need to recover certain range, aka in
raid56_parity_recover(), we will use the cached rbio, along with its
cached sectors (the full stripe is all cached).

This explains why we have no event raid56_scrub_read_recover()
triggered.

Since we have the cached P/Q which is calculated using the stale data,
the recovered one will just be stale.

In our particular test case, it will always return the same incorrect
metadata, thus causing the same error message "parent transid verify
failed on 39010304 wanted 9 found 7" again and again.

[BTRFS DESTRUCTIVE RMW PROBLEM]

Test case btrfs/125 (and above workload) always has its trouble with
the destructive read-modify-write (RMW) cycle:

        0       32K     64K
Data1:  | Good  | Good  |
Data2:  | Bad   | Bad   |
Parity: | Good  | Good  |

In above case, if we trigger any write into Data1, we will use the bad
data in Data2 to re-generate parity, killing the only chance to recovery
Data2, thus Data2 is lost forever.

This destructive RMW cycle is not specific to btrfs RAID56, but there
are some btrfs specific behaviors making the case even worse:

- Btrfs will cache sectors for unrelated vertical stripes.

  In above example, if we're only writing into 0~32K range, btrfs will
  still read data range (32K ~ 64K) of Data1, and (64K~128K) of Data2.
  This behavior is to cache sectors for later update.

  Incidentally commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio()
  subpage compatible") has a bug which makes RAID56 to never trust the
  cached sectors, thus slightly improve the situation for recovery.

  Unfortunately, follow up fix "btrfs: update stripe_sectors::uptodate in
  steal_rbio" will revert the behavior back to the old one.

- Btrfs raid56 partial write will update all P/Q sectors and cache them

  This means, even if data at (64K ~ 96K) of Data2 is free space, and
  only (96K ~ 128K) of Data2 is really stale data.
  And we write into that (96K ~ 128K), we will update all the parity
  sectors for the full stripe.

  This unnecessary behavior will completely kill the chance of recovery.

  Thankfully, an unrelated optimization "btrfs: only write the sectors
  in the vertical stripe which has data stripes" will prevent
  submitting the write bio for untouched vertical sectors.

  That optimization will keep the on-disk P/Q untouched for a chance for
  later recovery.

[FIX]
Although we have no good way to completely fix the destructive RMW
(unless we go full scrub for each partial write), we can still limit the
damage.

With patch "btrfs: only write the sectors in the vertical stripe which
has data stripes" now we won't really submit the P/Q of unrelated
vertical stripes, so the on-disk P/Q should still be fine.

Now we really need to do is just drop all the cached sectors when doing
recovery.

By this, we have a chance to read the original P/Q from disk, and have a
chance to recover the stale data, while still keep the cache to speed up
regular write path.

In fact, just dropping all the cache for recovery path is good enough to
allow the test case btrfs/125 along with the small script to pass
reliably.

The lack of metadata write after the degraded mount, and forced metadata
COW is saving us this time.

So this patch will fix the behavior by not trust any cache in
__raid56_parity_recover(), to solve the problem while still keep the
cache useful.

But please note that this test pass DOES NOT mean we have solved the
destructive RMW problem, we just do better damage control a little
better.

Related patches:

- btrfs: only write the sectors in the vertical stripe
- d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage compatible")
- btrfs: update stripe_sectors::uptodate in steal_rbio

Acked-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Qu Wenruo &lt;wqu@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>btrfs: only write the sectors in the vertical stripe which has data stripes</title>
<updated>2022-08-25T09:18:40+00:00</updated>
<author>
<name>Qu Wenruo</name>
<email>wqu@suse.com</email>
</author>
<published>2022-08-20T06:34:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=6fd4cea0440036484cc57e5ee4b1d0c15cb6f8ce'/>
<id>6fd4cea0440036484cc57e5ee4b1d0c15cb6f8ce</id>
<content type='text'>
commit bd8f7e627703ca5707833d623efcd43f104c7b3f upstream.

If we have only 8K partial write at the beginning of a full RAID56
stripe, we will write the following contents:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XXXXXXXXXXXXXXX|XXXXXXXXXXXXXXX|

|X| means the sector will be written back to disk.

Note that, although we won't write any sectors from disk 2, but we will
write the full 64KiB of parity to disk.

This behavior is fine for now, but not for the future (especially for
RAID56J, as we waste quite some space to journal the unused parity
stripes).

So here we will also utilize the btrfs_raid_bio::dbitmap, anytime we
queue a higher level bio into an rbio, we will update rbio::dbitmap to
indicate which vertical stripes we need to writeback.

And at finish_rmw(), we also check dbitmap to see if we need to write
any sector in the vertical stripe.

So after the patch, above example will only lead to the following
writeback pattern:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XX|            |               |

Acked-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Qu Wenruo &lt;wqu@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.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 bd8f7e627703ca5707833d623efcd43f104c7b3f upstream.

If we have only 8K partial write at the beginning of a full RAID56
stripe, we will write the following contents:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XXXXXXXXXXXXXXX|XXXXXXXXXXXXXXX|

|X| means the sector will be written back to disk.

Note that, although we won't write any sectors from disk 2, but we will
write the full 64KiB of parity to disk.

This behavior is fine for now, but not for the future (especially for
RAID56J, as we waste quite some space to journal the unused parity
stripes).

So here we will also utilize the btrfs_raid_bio::dbitmap, anytime we
queue a higher level bio into an rbio, we will update rbio::dbitmap to
indicate which vertical stripes we need to writeback.

And at finish_rmw(), we also check dbitmap to see if we need to write
any sector in the vertical stripe.

So after the patch, above example will only lead to the following
writeback pattern:

                    0  8K           32K             64K
Disk 1	(data):     |XX|            |               |
Disk 2  (data):     |               |               |
Disk 3  (parity):   |XX|            |               |

Acked-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Qu Wenruo &lt;wqu@suse.com&gt;
Signed-off-by: David Sterba &lt;dsterba@suse.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_session_destroy(): fix memory leak of skbs</title>
<updated>2022-08-25T09:18:39+00:00</updated>
<author>
<name>Fedor Pchelkin</name>
<email>pchelkin@ispras.ru</email>
</author>
<published>2022-08-05T15:02:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=04e41b6bacf474f5431491f92e981096e8cc8e93'/>
<id>04e41b6bacf474f5431491f92e981096e8cc8e93</id>
<content type='text'>
commit 8c21c54a53ab21842f5050fa090f26b03c0313d6 upstream.

We need to drop skb references taken in j1939_session_skb_queue() when
destroying a session in j1939_session_destroy(). Otherwise those skbs
would be lost.

Link to Syzkaller info and repro: https://forge.ispras.ru/issues/11743.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

V1: https://lore.kernel.org/all/20220708175949.539064-1-pchelkin@ispras.ru

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Signed-off-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20220805150216.66313-1-pchelkin@ispras.ru
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 8c21c54a53ab21842f5050fa090f26b03c0313d6 upstream.

We need to drop skb references taken in j1939_session_skb_queue() when
destroying a session in j1939_session_destroy(). Otherwise those skbs
would be lost.

Link to Syzkaller info and repro: https://forge.ispras.ru/issues/11743.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

V1: https://lore.kernel.org/all/20220708175949.539064-1-pchelkin@ispras.ru

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Signed-off-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20220805150216.66313-1-pchelkin@ispras.ru
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_sk_queue_activate_next_locked(): replace WARN_ON_ONCE with netdev_warn_once()</title>
<updated>2022-08-25T09:18:39+00:00</updated>
<author>
<name>Fedor Pchelkin</name>
<email>pchelkin@ispras.ru</email>
</author>
<published>2022-07-29T14:36:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=18e0ab31b028c99ba52d4e9a7fc7508bda1a9095'/>
<id>18e0ab31b028c99ba52d4e9a7fc7508bda1a9095</id>
<content type='text'>
commit 8ef49f7f8244424adcf4a546dba4cbbeb0b09c09 upstream.

We should warn user-space that it is doing something wrong when trying
to activate sessions with identical parameters but WARN_ON_ONCE macro
can not be used here as it serves a different purpose.

So it would be good to replace it with netdev_warn_once() message.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Signed-off-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20220729143655.1108297-1-pchelkin@ispras.ru
[mkl: fix indention]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 8ef49f7f8244424adcf4a546dba4cbbeb0b09c09 upstream.

We should warn user-space that it is doing something wrong when trying
to activate sessions with identical parameters but WARN_ON_ONCE macro
can not be used here as it serves a different purpose.

So it would be good to replace it with netdev_warn_once() message.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Signed-off-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20220729143655.1108297-1-pchelkin@ispras.ru
[mkl: fix indention]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing/probes: Have kprobes and uprobes use $COMM too</title>
<updated>2022-08-25T09:18:39+00:00</updated>
<author>
<name>Steven Rostedt (Google)</name>
<email>rostedt@goodmis.org</email>
</author>
<published>2022-08-20T13:43:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5c9637279f656b0da817ed9705dfbf86d78186be'/>
<id>5c9637279f656b0da817ed9705dfbf86d78186be</id>
<content type='text'>
commit ab8384442ee512fc0fc72deeb036110843d0e7ff upstream.

Both $comm and $COMM can be used to get current-&gt;comm in eprobes and the
filtering and histogram logic. Make kprobes and uprobes consistent in this
regard and allow both $comm and $COMM as well. Currently kprobes and
uprobes only handle $comm, which is inconsistent with the other utilities,
and can be confusing to users.

Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org
Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Tzvetomir Stoyanov &lt;tz.stoyanov@gmail.com&gt;
Cc: Tom Zanussi &lt;zanussi@kernel.org&gt;
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Suggested-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.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 ab8384442ee512fc0fc72deeb036110843d0e7ff upstream.

Both $comm and $COMM can be used to get current-&gt;comm in eprobes and the
filtering and histogram logic. Make kprobes and uprobes consistent in this
regard and allow both $comm and $COMM as well. Currently kprobes and
uprobes only handle $comm, which is inconsistent with the other utilities,
and can be confusing to users.

Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org
Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Tzvetomir Stoyanov &lt;tz.stoyanov@gmail.com&gt;
Cc: Tom Zanussi &lt;zanussi@kernel.org&gt;
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Suggested-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Acked-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.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>MIPS: tlbex: Explicitly compare _PAGE_NO_EXEC against 0</title>
<updated>2022-08-25T09:18:39+00:00</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2022-08-02T17:59:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5d8244d42d34e13de423c345ac2b6b66499098dc'/>
<id>5d8244d42d34e13de423c345ac2b6b66499098dc</id>
<content type='text'>
[ Upstream commit 74de14fe05dd6b151d73cb0c73c8ec874cbdcde6 ]

When CONFIG_XPA is enabled, Clang warns:

  arch/mips/mm/tlbex.c:629:24: error: converting the result of '&lt;&lt;' to a boolean; did you mean '(1 &lt;&lt; _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
          if (cpu_has_rixi &amp;&amp; !!_PAGE_NO_EXEC) {
                              ^
  arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
  # define _PAGE_NO_EXEC          (1 &lt;&lt; _PAGE_NO_EXEC_SHIFT)
                                     ^
  arch/mips/mm/tlbex.c:2568:24: error: converting the result of '&lt;&lt;' to a boolean; did you mean '(1 &lt;&lt; _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
          if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
                                ^
  arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
  # define _PAGE_NO_EXEC          (1 &lt;&lt; _PAGE_NO_EXEC_SHIFT)
                                     ^
  2 errors generated.

_PAGE_NO_EXEC can be '0' or '1 &lt;&lt; _PAGE_NO_EXEC_SHIFT' depending on the
build and runtime configuration, which is what the negation operators
are trying to convey. To silence the warning, explicitly compare against
0 so the result of the '&lt;&lt;' operator is not implicitly converted to a
boolean.

According to its documentation, GCC enables -Wint-in-bool-context with
-Wall but this warning is not visible when building the same
configuration with GCC. It appears GCC only warns when compiling C++,
not C, although the documentation makes no note of this:
https://godbolt.org/z/x39q3brxf

Reported-by: Sudip Mukherjee (Codethink) &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.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 74de14fe05dd6b151d73cb0c73c8ec874cbdcde6 ]

When CONFIG_XPA is enabled, Clang warns:

  arch/mips/mm/tlbex.c:629:24: error: converting the result of '&lt;&lt;' to a boolean; did you mean '(1 &lt;&lt; _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
          if (cpu_has_rixi &amp;&amp; !!_PAGE_NO_EXEC) {
                              ^
  arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
  # define _PAGE_NO_EXEC          (1 &lt;&lt; _PAGE_NO_EXEC_SHIFT)
                                     ^
  arch/mips/mm/tlbex.c:2568:24: error: converting the result of '&lt;&lt;' to a boolean; did you mean '(1 &lt;&lt; _PAGE_NO_EXEC_SHIFT) != 0'? [-Werror,-Wint-in-bool-context]
          if (!cpu_has_rixi || !_PAGE_NO_EXEC) {
                                ^
  arch/mips/include/asm/pgtable-bits.h:174:28: note: expanded from macro '_PAGE_NO_EXEC'
  # define _PAGE_NO_EXEC          (1 &lt;&lt; _PAGE_NO_EXEC_SHIFT)
                                     ^
  2 errors generated.

_PAGE_NO_EXEC can be '0' or '1 &lt;&lt; _PAGE_NO_EXEC_SHIFT' depending on the
build and runtime configuration, which is what the negation operators
are trying to convey. To silence the warning, explicitly compare against
0 so the result of the '&lt;&lt;' operator is not implicitly converted to a
boolean.

According to its documentation, GCC enables -Wint-in-bool-context with
-Wall but this warning is not visible when building the same
configuration with GCC. It appears GCC only warns when compiling C++,
not C, although the documentation makes no note of this:
https://godbolt.org/z/x39q3brxf

Reported-by: Sudip Mukherjee (Codethink) &lt;sudipm.mukherjee@gmail.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>video: fbdev: i740fb: Check the argument of i740_calc_vclk()</title>
<updated>2022-08-25T09:18:38+00:00</updated>
<author>
<name>Zheyu Ma</name>
<email>zheyuma97@gmail.com</email>
</author>
<published>2022-08-03T09:24:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=2b7f559152a33c55f51b569b22efbe5e24886798'/>
<id>2b7f559152a33c55f51b569b22efbe5e24886798</id>
<content type='text'>
[ Upstream commit 40bf722f8064f50200b8c4f8946cd625b441dda9 ]

Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug.

If the user provides an improper 'pixclock' value that makes the argumet
of i740_calc_vclk() less than 'I740_RFREQ_FIX', it will cause a
divide-by-zero bug in:
    drivers/video/fbdev/i740fb.c:353 p_best = min(15, ilog2(I740_MAX_VCO_FREQ / (freq / I740_RFREQ_FIX)));

The following log can reveal it:

divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:i740_calc_vclk drivers/video/fbdev/i740fb.c:353 [inline]
RIP: 0010:i740fb_decode_var drivers/video/fbdev/i740fb.c:646 [inline]
RIP: 0010:i740fb_set_par+0x163f/0x3b70 drivers/video/fbdev/i740fb.c:742
Call Trace:
 fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1034
 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189

Fix this by checking the argument of i740_calc_vclk() first.

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.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 40bf722f8064f50200b8c4f8946cd625b441dda9 ]

Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug.

If the user provides an improper 'pixclock' value that makes the argumet
of i740_calc_vclk() less than 'I740_RFREQ_FIX', it will cause a
divide-by-zero bug in:
    drivers/video/fbdev/i740fb.c:353 p_best = min(15, ilog2(I740_MAX_VCO_FREQ / (freq / I740_RFREQ_FIX)));

The following log can reveal it:

divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:i740_calc_vclk drivers/video/fbdev/i740fb.c:353 [inline]
RIP: 0010:i740fb_decode_var drivers/video/fbdev/i740fb.c:646 [inline]
RIP: 0010:i740fb_set_par+0x163f/0x3b70 drivers/video/fbdev/i740fb.c:742
Call Trace:
 fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1034
 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189

Fix this by checking the argument of i740_calc_vclk() first.

Signed-off-by: Zheyu Ma &lt;zheyuma97@gmail.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64: Init jump labels before parse_early_param()</title>
<updated>2022-08-25T09:18:38+00:00</updated>
<author>
<name>Zhouyi Zhou</name>
<email>zhouzhouyi@gmail.com</email>
</author>
<published>2022-07-26T01:57:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5e14b04c8459afbeea1eeb74e81af86d7b196a4d'/>
<id>5e14b04c8459afbeea1eeb74e81af86d7b196a4d</id>
<content type='text'>
[ Upstream commit ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 ]

On 64-bit, calling jump_label_init() in setup_feature_keys() is too
late because static keys may be used in subroutines of
parse_early_param() which is again subroutine of early_init_devtree().

For example booting with "threadirqs":

  static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init()
  WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120
  ...
  NIP static_key_enable_cpuslocked+0xfc/0x120
  LR  static_key_enable_cpuslocked+0xf8/0x120
  Call Trace:
    static_key_enable_cpuslocked+0xf8/0x120 (unreliable)
    static_key_enable+0x30/0x50
    setup_forced_irqthreads+0x28/0x40
    do_early_param+0xa0/0x108
    parse_args+0x290/0x4e0
    parse_early_options+0x48/0x5c
    parse_early_param+0x58/0x84
    early_init_devtree+0xd4/0x518
    early_setup+0xb4/0x214

So call jump_label_init() just before parse_early_param() in
early_init_devtree().

Suggested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Zhouyi Zhou &lt;zhouzhouyi@gmail.com&gt;
[mpe: Add call trace to change log and minor wording edits.]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.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 ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 ]

On 64-bit, calling jump_label_init() in setup_feature_keys() is too
late because static keys may be used in subroutines of
parse_early_param() which is again subroutine of early_init_devtree().

For example booting with "threadirqs":

  static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init()
  WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120
  ...
  NIP static_key_enable_cpuslocked+0xfc/0x120
  LR  static_key_enable_cpuslocked+0xf8/0x120
  Call Trace:
    static_key_enable_cpuslocked+0xf8/0x120 (unreliable)
    static_key_enable+0x30/0x50
    setup_forced_irqthreads+0x28/0x40
    do_early_param+0xa0/0x108
    parse_args+0x290/0x4e0
    parse_early_options+0x48/0x5c
    parse_early_param+0x58/0x84
    early_init_devtree+0xd4/0x518
    early_setup+0xb4/0x214

So call jump_label_init() just before parse_early_param() in
early_init_devtree().

Suggested-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Zhouyi Zhou &lt;zhouzhouyi@gmail.com&gt;
[mpe: Add call trace to change log and minor wording edits.]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>smb3: check xattr value length earlier</title>
<updated>2022-08-25T09:18:38+00:00</updated>
<author>
<name>Steve French</name>
<email>stfrench@microsoft.com</email>
</author>
<published>2022-07-12T16:43:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=720f6112c393e97df955e558699555d4a6431b4b'/>
<id>720f6112c393e97df955e558699555d4a6431b4b</id>
<content type='text'>
[ Upstream commit 5fa2cffba0b82336a2244d941322eb1627ff787b ]

Coverity complains about assigning a pointer based on
value length before checking that value length goes
beyond the end of the SMB.  Although this is even more
unlikely as value length is a single byte, and the
pointer is not dereferenced until laterm, it is clearer
to check the lengths first.

Addresses-Coverity: 1467704 ("Speculative execution data leak")
Reviewed-by: Ronnie Sahlberg &lt;lsahlber@redhat.com&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&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 5fa2cffba0b82336a2244d941322eb1627ff787b ]

Coverity complains about assigning a pointer based on
value length before checking that value length goes
beyond the end of the SMB.  Although this is even more
unlikely as value length is a single byte, and the
pointer is not dereferenced until laterm, it is clearer
to check the lengths first.

Addresses-Coverity: 1467704 ("Speculative execution data leak")
Reviewed-by: Ronnie Sahlberg &lt;lsahlber@redhat.com&gt;
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
