<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git, branch v5.18.19</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.18.19</id>
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<updated>2022-08-21T13:18:56Z</updated>
<entry>
<title>Linux 5.18.19</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2022-08-21T13:18:56Z</published>
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<id>urn:sha1:22a992953741ad79c07890d3f4104585e52ef26b</id>
<content type='text'>
Link: https://lore.kernel.org/r/20220819153710.430046927@linuxfoundation.org
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Ron Economos &lt;re@w6rz.net&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>arm64: kexec_file: use more system keyrings to verify kernel image signature</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Coiby Xu</name>
<email>coxu@redhat.com</email>
</author>
<published>2022-07-14T13:40:26Z</published>
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<id>urn:sha1:f7cb29b2a8e5d607b694ef64189cb461a0b02e9e</id>
<content type='text'>
commit 0d519cadf75184a24313568e7f489a7fc9b1be3b upstream.

Currently, when loading a kernel image via the kexec_file_load() system
call, arm64 can only use the .builtin_trusted_keys keyring to verify
a signature whereas x86 can use three more keyrings i.e.
.secondary_trusted_keys, .machine and .platform keyrings. For example,
one resulting problem is kexec'ing a kernel image  would be rejected
with the error "Lockdown: kexec: kexec of unsigned images is restricted;
see man kernel_lockdown.7".

This patch set enables arm64 to make use of the same keyrings as x86 to
verify the signature kexec'ed kernel image.

Fixes: 732b7b93d849 ("arm64: kexec_file: add kernel signature verification support")
Cc: stable@vger.kernel.org # 105e10e2cf1c: kexec_file: drop weak attribute from functions
Cc: stable@vger.kernel.org # 34d5960af253: kexec: clean up arch_kexec_kernel_verify_sig
Cc: stable@vger.kernel.org # 83b7bb2d49ae: kexec, KEYS: make the code in bzImage64_verify_sig generic
Acked-by: Baoquan He &lt;bhe@redhat.com&gt;
Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Co-developed-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Signed-off-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Acked-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Coiby Xu &lt;coxu@redhat.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>kexec, KEYS: make the code in bzImage64_verify_sig generic</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Coiby Xu</name>
<email>coxu@redhat.com</email>
</author>
<published>2022-07-14T13:40:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8fd872cddf2a46f6d60e616832b7686d3f5fe40a'/>
<id>urn:sha1:8fd872cddf2a46f6d60e616832b7686d3f5fe40a</id>
<content type='text'>
commit c903dae8941deb55043ee46ded29e84e97cd84bb upstream.

commit 278311e417be ("kexec, KEYS: Make use of platform keyring for
signature verify") adds platform keyring support on x86 kexec but not
arm64.

The code in bzImage64_verify_sig uses the keys on the
.builtin_trusted_keys, .machine, if configured and enabled,
.secondary_trusted_keys, also if configured, and .platform keyrings
to verify the signed kernel image as PE file.

Cc: kexec@lists.infradead.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Reviewed-by: Michal Suchanek &lt;msuchanek@suse.de&gt;
Signed-off-by: Coiby Xu &lt;coxu@redhat.com&gt;
Signed-off-by: Mimi Zohar &lt;zohar@linux.ibm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>btrfs: raid56: don't trust any cached sector in __raid56_parity_recover()</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Qu Wenruo</name>
<email>wqu@suse.com</email>
</author>
<published>2022-08-19T07:40:59Z</published>
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<id>urn:sha1:3efab6d817d5a4f238c4e9c6ab908a4a23f99cf2</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>
</entry>
<entry>
<title>btrfs: only write the sectors in the vertical stripe which has data stripes</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Qu Wenruo</name>
<email>wqu@suse.com</email>
</author>
<published>2022-08-19T07:40:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2bec2cb847b0ec604c34caebe1dd19a44afbce0b'/>
<id>urn:sha1:2bec2cb847b0ec604c34caebe1dd19a44afbce0b</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>
</entry>
<entry>
<title>net_sched: cls_route: disallow handle of 0</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Jamal Hadi Salim</name>
<email>jhs@mojatatu.com</email>
</author>
<published>2022-08-14T11:27:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c0931e464b87d981515cfc19d28361d187b9e12f'/>
<id>urn:sha1:c0931e464b87d981515cfc19d28361d187b9e12f</id>
<content type='text'>
commit 02799571714dc5dd6948824b9d080b44a295f695 upstream.

Follows up on:
https://lore.kernel.org/all/20220809170518.164662-1-cascardo@canonical.com/

handle of 0 implies from/to of universe realm which is not very
sensible.

Lets see what this patch will do:
$sudo tc qdisc add dev $DEV root handle 1:0 prio

//lets manufacture a way to insert handle of 0
$sudo tc filter add dev $DEV parent 1:0 protocol ip prio 100 \
route to 0 from 0 classid 1:10 action ok

//gets rejected...
Error: handle of 0 is not valid.
We have an error talking to the kernel, -1

//lets create a legit entry..
sudo tc filter add dev $DEV parent 1:0 protocol ip prio 100 route from 10 \
classid 1:10 action ok

//what did the kernel insert?
$sudo tc filter ls dev $DEV parent 1:0
filter protocol ip pref 100 route chain 0
filter protocol ip pref 100 route chain 0 fh 0x000a8000 flowid 1:10 from 10
	action order 1: gact action pass
	 random type none pass val 0
	 index 1 ref 1 bind 1

//Lets try to replace that legit entry with a handle of 0
$ sudo tc filter replace dev $DEV parent 1:0 protocol ip prio 100 \
handle 0x000a8000 route to 0 from 0 classid 1:10 action drop

Error: Replacing with handle of 0 is invalid.
We have an error talking to the kernel, -1

And last, lets run Cascardo's POC:
$ ./poc
0
0
-22
-22
-22

Signed-off-by: Jamal Hadi Salim &lt;jhs@mojatatu.com&gt;
Acked-by: Stephen Hemminger &lt;stephen@networkplumber.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>tee: add overflow check in register_shm_helper()</title>
<updated>2022-08-21T13:18:56Z</updated>
<author>
<name>Jens Wiklander</name>
<email>jens.wiklander@linaro.org</email>
</author>
<published>2022-08-18T11:08:59Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=2f8e79a1a6128214cb9b205a9869341af5dfb16b'/>
<id>urn:sha1:2f8e79a1a6128214cb9b205a9869341af5dfb16b</id>
<content type='text'>
commit 573ae4f13f630d6660008f1974c0a8a29c30e18a upstream.

With special lengths supplied by user space, register_shm_helper() has
an integer overflow when calculating the number of pages covered by a
supplied user space memory region.

This causes internal_get_user_pages_fast() a helper function of
pin_user_pages_fast() to do a NULL pointer dereference:

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
  Modules linked in:
  CPU: 1 PID: 173 Comm: optee_example_a Not tainted 5.19.0 #11
  Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
  pc : internal_get_user_pages_fast+0x474/0xa80
  Call trace:
   internal_get_user_pages_fast+0x474/0xa80
   pin_user_pages_fast+0x24/0x4c
   register_shm_helper+0x194/0x330
   tee_shm_register_user_buf+0x78/0x120
   tee_ioctl+0xd0/0x11a0
   __arm64_sys_ioctl+0xa8/0xec
   invoke_syscall+0x48/0x114

Fix this by adding an an explicit call to access_ok() in
tee_shm_register_user_buf() to catch an invalid user space address
early.

Fixes: 033ddf12bcf5 ("tee: add register user memory")
Cc: stable@vger.kernel.org
Reported-by: Nimish Mishra &lt;neelam.nimish@gmail.com&gt;
Reported-by: Anirban Chakraborty &lt;ch.anirban00727@gmail.com&gt;
Reported-by: Debdeep Mukhopadhyay &lt;debdeep.mukhopadhyay@gmail.com&gt;
Suggested-by: Jerome Forissier &lt;jerome.forissier@linaro.org&gt;
Signed-off-by: Jens Wiklander &lt;jens.wiklander@linaro.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Linux 5.18.18</title>
<updated>2022-08-17T12:42:36Z</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2022-08-17T12:42:36Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=07e0b709cab7dc987b5071443789865e20481119'/>
<id>urn:sha1:07e0b709cab7dc987b5071443789865e20481119</id>
<content type='text'>
Link: https://lore.kernel.org/r/20220815180429.240518113@linuxfoundation.org
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Link: https://lore.kernel.org/r/20220816124604.978842485@linuxfoundation.org
Tested-by: Linux Kernel Functional Testing &lt;lkft@linaro.org&gt;
Tested-by: Ron Economos &lt;re@w6rz.net&gt;
Tested-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>mm: introduce clear_highpage_kasan_tagged</title>
<updated>2022-08-17T12:42:36Z</updated>
<author>
<name>Andrey Konovalov</name>
<email>andreyknvl@google.com</email>
</author>
<published>2022-06-09T18:18:46Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=043fcdc2876029c45bf781a3f9ef31fc0b35e881'/>
<id>urn:sha1:043fcdc2876029c45bf781a3f9ef31fc0b35e881</id>
<content type='text'>
commit d9da8f6cf55eeca642c021912af1890002464c64 upstream.

Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a
page potentially tagged by KASAN.

This helper is used by the following patch.

Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Jiri Slaby &lt;jirislaby@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression</title>
<updated>2022-08-17T12:42:36Z</updated>
<author>
<name>Luiz Augusto von Dentz</name>
<email>luiz.von.dentz@intel.com</email>
</author>
<published>2022-08-01T20:52:07Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=11e008e599700f1ff1f39b9190fdb2fee972996b'/>
<id>urn:sha1:11e008e599700f1ff1f39b9190fdb2fee972996b</id>
<content type='text'>
commit 332f1795ca202489c665a75e62e18ff6284de077 upstream.

The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused
by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch
static checker warning:

        net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm()
        error: we previously assumed 'c' could be null (see line 1996)

Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put")
Reported-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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