<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/fs, branch v5.4.152</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>silence nfscache allocation warnings with kvzalloc</title>
<updated>2021-10-09T12:39:50+00:00</updated>
<author>
<name>Rik van Riel</name>
<email>riel@surriel.com</email>
</author>
<published>2020-09-14T17:07:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fecbe957ef4d869a3b185c5f4a8bc535d8b8f05b'/>
<id>fecbe957ef4d869a3b185c5f4a8bc535d8b8f05b</id>
<content type='text'>
commit 8c38b705b4f4ca4e7f9cc116141bc38391917c30 upstream.

silence nfscache allocation warnings with kvzalloc

Currently nfsd_reply_cache_init attempts hash table allocation through
kmalloc, and manually falls back to vzalloc if that fails. This makes
the code a little larger than needed, and creates a significant amount
of serial console spam if you have enough systems.

Switching to kvzalloc gets rid of the allocation warnings, and makes
the code a little cleaner too as a side effect.

Freeing of nn-&gt;drc_hashtbl is already done using kvfree currently.

Signed-off-by: Rik van Riel &lt;riel@surriel.com&gt;
Signed-off-by: J. Bruce Fields &lt;bfields@redhat.com&gt;
Cc: Krzysztof Olędzki &lt;ole@ans.pl&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 8c38b705b4f4ca4e7f9cc116141bc38391917c30 upstream.

silence nfscache allocation warnings with kvzalloc

Currently nfsd_reply_cache_init attempts hash table allocation through
kmalloc, and manually falls back to vzalloc if that fails. This makes
the code a little larger than needed, and creates a significant amount
of serial console spam if you have enough systems.

Switching to kvzalloc gets rid of the allocation warnings, and makes
the code a little cleaner too as a side effect.

Freeing of nn-&gt;drc_hashtbl is already done using kvfree currently.

Signed-off-by: Rik van Riel &lt;riel@surriel.com&gt;
Signed-off-by: J. Bruce Fields &lt;bfields@redhat.com&gt;
Cc: Krzysztof Olędzki &lt;ole@ans.pl&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext2: fix sleeping in atomic bugs on error</title>
<updated>2021-10-09T12:39:49+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2021-09-21T20:32:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f194b57696a332dc100907b92b71650bff8adad'/>
<id>4f194b57696a332dc100907b92b71650bff8adad</id>
<content type='text'>
[ Upstream commit 372d1f3e1bfede719864d0d1fbf3146b1e638c88 ]

The ext2_error() function syncs the filesystem so it sleeps.  The caller
is holding a spinlock so it's not allowed to sleep.

   ext2_statfs() &lt;- disables preempt
   -&gt; ext2_count_free_blocks()
      -&gt; ext2_get_group_desc()

Fix this by using WARN() to print an error message and a stack trace
instead of using ext2_error().

Link: https://lore.kernel.org/r/20210921203233.GA16529@kili
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&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 372d1f3e1bfede719864d0d1fbf3146b1e638c88 ]

The ext2_error() function syncs the filesystem so it sleeps.  The caller
is holding a spinlock so it's not allowed to sleep.

   ext2_statfs() &lt;- disables preempt
   -&gt; ext2_count_free_blocks()
      -&gt; ext2_get_group_desc()

Fix this by using WARN() to print an error message and a stack trace
instead of using ext2_error().

Link: https://lore.kernel.org/r/20210921203233.GA16529@kili
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fix potential infinite loop in ext4_dx_readdir()</title>
<updated>2021-10-06T13:42:37+00:00</updated>
<author>
<name>yangerkun</name>
<email>yangerkun@huawei.com</email>
</author>
<published>2021-09-14T11:14:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d518ea03145ce4b770081fb89ea883f90a82525a'/>
<id>d518ea03145ce4b770081fb89ea883f90a82525a</id>
<content type='text'>
commit 42cb447410d024e9d54139ae9c21ea132a8c384c upstream.

When ext4_htree_fill_tree() fails, ext4_dx_readdir() can run into an
infinite loop since if info-&gt;last_pos != ctx-&gt;pos this will reset the
directory scan and reread the failing entry.  For example:

1. a dx_dir which has 3 block, block 0 as dx_root block, block 1/2 as
   leaf block which own the ext4_dir_entry_2
2. block 1 read ok and call_filldir which will fill the dirent and update
   the ctx-&gt;pos
3. block 2 read fail, but we has already fill some dirent, so we will
   return back to userspace will a positive return val(see ksys_getdents64)
4. the second ext4_dx_readdir will reset the world since info-&gt;last_pos
   != ctx-&gt;pos, and will also init the curr_hash which pos to block 1
5. So we will read block1 too, and once block2 still read fail, we can
   only fill one dirent because the hash of the entry in block1(besides
   the last one) won't greater than curr_hash
6. this time, we forget update last_pos too since the read for block2
   will fail, and since we has got the one entry, ksys_getdents64 can
   return success
7. Latter we will trapped in a loop with step 4~6

Cc: stable@kernel.org
Signed-off-by: yangerkun &lt;yangerkun@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Link: https://lore.kernel.org/r/20210914111415.3921954-1-yangerkun@huawei.com
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 42cb447410d024e9d54139ae9c21ea132a8c384c upstream.

When ext4_htree_fill_tree() fails, ext4_dx_readdir() can run into an
infinite loop since if info-&gt;last_pos != ctx-&gt;pos this will reset the
directory scan and reread the failing entry.  For example:

1. a dx_dir which has 3 block, block 0 as dx_root block, block 1/2 as
   leaf block which own the ext4_dir_entry_2
2. block 1 read ok and call_filldir which will fill the dirent and update
   the ctx-&gt;pos
3. block 2 read fail, but we has already fill some dirent, so we will
   return back to userspace will a positive return val(see ksys_getdents64)
4. the second ext4_dx_readdir will reset the world since info-&gt;last_pos
   != ctx-&gt;pos, and will also init the curr_hash which pos to block 1
5. So we will read block1 too, and once block2 still read fail, we can
   only fill one dirent because the hash of the entry in block1(besides
   the last one) won't greater than curr_hash
6. this time, we forget update last_pos too since the read for block2
   will fail, and since we has got the one entry, ksys_getdents64 can
   return success
7. Latter we will trapped in a loop with step 4~6

Cc: stable@kernel.org
Signed-off-by: yangerkun &lt;yangerkun@huawei.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Link: https://lore.kernel.org/r/20210914111415.3921954-1-yangerkun@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fix reserved space counter leakage</title>
<updated>2021-10-06T13:42:37+00:00</updated>
<author>
<name>Jeffle Xu</name>
<email>jefflexu@linux.alibaba.com</email>
</author>
<published>2021-08-23T06:13:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=59c19fdcde79287a7a45813eec1db9ebf784f727'/>
<id>59c19fdcde79287a7a45813eec1db9ebf784f727</id>
<content type='text'>
commit 6fed83957f21eff11c8496e9f24253b03d2bc1dc upstream.

When ext4_insert_delayed block receives and recovers from an error from
ext4_es_insert_delayed_block(), e.g., ENOMEM, it does not release the
space it has reserved for that block insertion as it should. One effect
of this bug is that s_dirtyclusters_counter is not decremented and
remains incorrectly elevated until the file system has been unmounted.
This can result in premature ENOSPC returns and apparent loss of free
space.

Another effect of this bug is that
/sys/fs/ext4/&lt;dev&gt;/delayed_allocation_blocks can remain non-zero even
after syncfs has been executed on the filesystem.

Besides, add check for s_dirtyclusters_counter when inode is going to be
evicted and freed. s_dirtyclusters_counter can still keep non-zero until
inode is written back in .evict_inode(), and thus the check is delayed
to .destroy_inode().

Fixes: 51865fda28e5 ("ext4: let ext4 maintain extent status tree")
Cc: stable@kernel.org
Suggested-by: Gao Xiang &lt;hsiangkao@linux.alibaba.com&gt;
Signed-off-by: Jeffle Xu &lt;jefflexu@linux.alibaba.com&gt;
Reviewed-by: Eric Whitney &lt;enwlinux@gmail.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Link: https://lore.kernel.org/r/20210823061358.84473-1-jefflexu@linux.alibaba.com
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 6fed83957f21eff11c8496e9f24253b03d2bc1dc upstream.

When ext4_insert_delayed block receives and recovers from an error from
ext4_es_insert_delayed_block(), e.g., ENOMEM, it does not release the
space it has reserved for that block insertion as it should. One effect
of this bug is that s_dirtyclusters_counter is not decremented and
remains incorrectly elevated until the file system has been unmounted.
This can result in premature ENOSPC returns and apparent loss of free
space.

Another effect of this bug is that
/sys/fs/ext4/&lt;dev&gt;/delayed_allocation_blocks can remain non-zero even
after syncfs has been executed on the filesystem.

Besides, add check for s_dirtyclusters_counter when inode is going to be
evicted and freed. s_dirtyclusters_counter can still keep non-zero until
inode is written back in .evict_inode(), and thus the check is delayed
to .destroy_inode().

Fixes: 51865fda28e5 ("ext4: let ext4 maintain extent status tree")
Cc: stable@kernel.org
Suggested-by: Gao Xiang &lt;hsiangkao@linux.alibaba.com&gt;
Signed-off-by: Jeffle Xu &lt;jefflexu@linux.alibaba.com&gt;
Reviewed-by: Eric Whitney &lt;enwlinux@gmail.com&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Link: https://lore.kernel.org/r/20210823061358.84473-1-jefflexu@linux.alibaba.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ext4: fix loff_t overflow in ext4_max_bitmap_size()</title>
<updated>2021-10-06T13:42:36+00:00</updated>
<author>
<name>Ritesh Harjani</name>
<email>riteshh@linux.ibm.com</email>
</author>
<published>2021-06-05T05:09:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c4b8db2b4755f2e13569a00d8d52d43794a0d336'/>
<id>c4b8db2b4755f2e13569a00d8d52d43794a0d336</id>
<content type='text'>
commit 75ca6ad408f459f00b09a64f04c774559848c097 upstream.

We should use unsigned long long rather than loff_t to avoid
overflow in ext4_max_bitmap_size() for comparison before returning.
w/o this patch sbi-&gt;s_bitmap_maxbytes was becoming a negative
value due to overflow of upper_limit (with has_huge_files as true)

Below is a quick test to trigger it on a 64KB pagesize system.

sudo mkfs.ext4 -b 65536 -O ^has_extents,^64bit /dev/loop2
sudo mount /dev/loop2 /mnt
sudo echo "hello" &gt; /mnt/hello 	-&gt; This will error out with
				"echo: write error: File too large"

Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/594f409e2c543e90fd836b78188dfa5c575065ba.1622867594.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&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 75ca6ad408f459f00b09a64f04c774559848c097 upstream.

We should use unsigned long long rather than loff_t to avoid
overflow in ext4_max_bitmap_size() for comparison before returning.
w/o this patch sbi-&gt;s_bitmap_maxbytes was becoming a negative
value due to overflow of upper_limit (with has_huge_files as true)

Below is a quick test to trigger it on a 64KB pagesize system.

sudo mkfs.ext4 -b 65536 -O ^has_extents,^64bit /dev/loop2
sudo mount /dev/loop2 /mnt
sudo echo "hello" &gt; /mnt/hello 	-&gt; This will error out with
				"echo: write error: File too large"

Signed-off-by: Ritesh Harjani &lt;riteshh@linux.ibm.com&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/594f409e2c543e90fd836b78188dfa5c575065ba.1622867594.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o &lt;tytso@mit.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>debugfs: debugfs_create_file_size(): use IS_ERR to check for error</title>
<updated>2021-10-06T13:42:35+00:00</updated>
<author>
<name>Nirmoy Das</name>
<email>nirmoy.das@amd.com</email>
</author>
<published>2021-09-02T10:29:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=91d5de0b710b00d5dbee863fee9064005ad7750d'/>
<id>91d5de0b710b00d5dbee863fee9064005ad7750d</id>
<content type='text'>
commit af505cad9567f7a500d34bf183696d570d7f6810 upstream.

debugfs_create_file() returns encoded error so use IS_ERR for checking
return value.

Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Nirmoy Das &lt;nirmoy.das@amd.com&gt;
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Cc: stable &lt;stable@vger.kernel.org&gt;
References: https://gitlab.freedesktop.org/drm/amd/-/issues/1686
Link: https://lore.kernel.org/r/20210902102917.2233-1-nirmoy.das@amd.com
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 af505cad9567f7a500d34bf183696d570d7f6810 upstream.

debugfs_create_file() returns encoded error so use IS_ERR for checking
return value.

Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Nirmoy Das &lt;nirmoy.das@amd.com&gt;
Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL")
Cc: stable &lt;stable@vger.kernel.org&gt;
References: https://gitlab.freedesktop.org/drm/amd/-/issues/1686
Link: https://lore.kernel.org/r/20210902102917.2233-1-nirmoy.das@amd.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>elf: don't use MAP_FIXED_NOREPLACE for elf interpreter mappings</title>
<updated>2021-10-06T13:42:35+00:00</updated>
<author>
<name>Chen Jingwen</name>
<email>chenjingwen6@huawei.com</email>
</author>
<published>2021-09-28T12:56:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=98574c91e3739ed8d499428958e567e832fa7f35'/>
<id>98574c91e3739ed8d499428958e567e832fa7f35</id>
<content type='text'>
commit 9b2f72cc0aa4bb444541bb87581c35b7508b37d3 upstream.

In commit b212921b13bd ("elf: don't use MAP_FIXED_NOREPLACE for elf
executable mappings") we still leave MAP_FIXED_NOREPLACE in place for
load_elf_interp.

Unfortunately, this will cause kernel to fail to start with:

    1 (init): Uhuuh, elf segment at 00003ffff7ffd000 requested but the memory is mapped already
    Failed to execute /init (error -17)

The reason is that the elf interpreter (ld.so) has overlapping segments.

  readelf -l ld-2.31.so
  Program Headers:
    Type           Offset             VirtAddr           PhysAddr
                   FileSiz            MemSiz              Flags  Align
    LOAD           0x0000000000000000 0x0000000000000000 0x0000000000000000
                   0x000000000002c94c 0x000000000002c94c  R E    0x10000
    LOAD           0x000000000002dae0 0x000000000003dae0 0x000000000003dae0
                   0x00000000000021e8 0x0000000000002320  RW     0x10000
    LOAD           0x000000000002fe00 0x000000000003fe00 0x000000000003fe00
                   0x00000000000011ac 0x0000000000001328  RW     0x10000

The reason for this problem is the same as described in commit
ad55eac74f20 ("elf: enforce MAP_FIXED on overlaying elf segments").

Not only executable binaries, elf interpreters (e.g. ld.so) can have
overlapping elf segments, so we better drop MAP_FIXED_NOREPLACE and go
back to MAP_FIXED in load_elf_interp.

Fixes: 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map")
Cc: &lt;stable@vger.kernel.org&gt; # v4.19
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Chen Jingwen &lt;chenjingwen6@huawei.com&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 9b2f72cc0aa4bb444541bb87581c35b7508b37d3 upstream.

In commit b212921b13bd ("elf: don't use MAP_FIXED_NOREPLACE for elf
executable mappings") we still leave MAP_FIXED_NOREPLACE in place for
load_elf_interp.

Unfortunately, this will cause kernel to fail to start with:

    1 (init): Uhuuh, elf segment at 00003ffff7ffd000 requested but the memory is mapped already
    Failed to execute /init (error -17)

The reason is that the elf interpreter (ld.so) has overlapping segments.

  readelf -l ld-2.31.so
  Program Headers:
    Type           Offset             VirtAddr           PhysAddr
                   FileSiz            MemSiz              Flags  Align
    LOAD           0x0000000000000000 0x0000000000000000 0x0000000000000000
                   0x000000000002c94c 0x000000000002c94c  R E    0x10000
    LOAD           0x000000000002dae0 0x000000000003dae0 0x000000000003dae0
                   0x00000000000021e8 0x0000000000002320  RW     0x10000
    LOAD           0x000000000002fe00 0x000000000003fe00 0x000000000003fe00
                   0x00000000000011ac 0x0000000000001328  RW     0x10000

The reason for this problem is the same as described in commit
ad55eac74f20 ("elf: enforce MAP_FIXED on overlaying elf segments").

Not only executable binaries, elf interpreters (e.g. ld.so) can have
overlapping elf segments, so we better drop MAP_FIXED_NOREPLACE and go
back to MAP_FIXED in load_elf_interp.

Fixes: 4ed28639519c ("fs, elf: drop MAP_FIXED usage from elf_map")
Cc: &lt;stable@vger.kernel.org&gt; # v4.19
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Chen Jingwen &lt;chenjingwen6@huawei.com&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>fs-verity: fix signed integer overflow with i_size near S64_MAX</title>
<updated>2021-10-06T13:42:30+00:00</updated>
<author>
<name>Eric Biggers</name>
<email>ebiggers@google.com</email>
</author>
<published>2021-09-16T20:34:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=504cf969d5856bd9a084da3bfe636ae4b42a6fe8'/>
<id>504cf969d5856bd9a084da3bfe636ae4b42a6fe8</id>
<content type='text'>
commit 80f6e3080bfcf865062a926817b3ca6c4a137a57 upstream.

If the file size is almost S64_MAX, the calculated number of Merkle tree
levels exceeds FS_VERITY_MAX_LEVELS, causing FS_IOC_ENABLE_VERITY to
fail.  This is unintentional, since as the comment above the definition
of FS_VERITY_MAX_LEVELS states, it is enough for over U64_MAX bytes of
data using SHA-256 and 4K blocks.  (Specifically, 4096*128**8 &gt;= 2**64.)

The bug is actually that when the number of blocks in the first level is
calculated from i_size, there is a signed integer overflow due to i_size
being signed.  Fix this by treating i_size as unsigned.

This was found by the new test "generic: test fs-verity EFBIG scenarios"
(https://lkml.kernel.org/r/b1d116cd4d0ea74b9cd86f349c672021e005a75c.1631558495.git.boris@bur.io).

This didn't affect ext4 or f2fs since those have a smaller maximum file
size, but it did affect btrfs which allows files up to S64_MAX bytes.

Reported-by: Boris Burkov &lt;boris@bur.io&gt;
Fixes: 3fda4c617e84 ("fs-verity: implement FS_IOC_ENABLE_VERITY ioctl")
Fixes: fd2d1acfcadf ("fs-verity: add the hook for file -&gt;open()")
Cc: &lt;stable@vger.kernel.org&gt; # v5.4+
Reviewed-by: Boris Burkov &lt;boris@bur.io&gt;
Link: https://lore.kernel.org/r/20210916203424.113376-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.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 80f6e3080bfcf865062a926817b3ca6c4a137a57 upstream.

If the file size is almost S64_MAX, the calculated number of Merkle tree
levels exceeds FS_VERITY_MAX_LEVELS, causing FS_IOC_ENABLE_VERITY to
fail.  This is unintentional, since as the comment above the definition
of FS_VERITY_MAX_LEVELS states, it is enough for over U64_MAX bytes of
data using SHA-256 and 4K blocks.  (Specifically, 4096*128**8 &gt;= 2**64.)

The bug is actually that when the number of blocks in the first level is
calculated from i_size, there is a signed integer overflow due to i_size
being signed.  Fix this by treating i_size as unsigned.

This was found by the new test "generic: test fs-verity EFBIG scenarios"
(https://lkml.kernel.org/r/b1d116cd4d0ea74b9cd86f349c672021e005a75c.1631558495.git.boris@bur.io).

This didn't affect ext4 or f2fs since those have a smaller maximum file
size, but it did affect btrfs which allows files up to S64_MAX bytes.

Reported-by: Boris Burkov &lt;boris@bur.io&gt;
Fixes: 3fda4c617e84 ("fs-verity: implement FS_IOC_ENABLE_VERITY ioctl")
Fixes: fd2d1acfcadf ("fs-verity: add the hook for file -&gt;open()")
Cc: &lt;stable@vger.kernel.org&gt; # v5.4+
Reviewed-by: Boris Burkov &lt;boris@bur.io&gt;
Link: https://lore.kernel.org/r/20210916203424.113376-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers &lt;ebiggers@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>qnx4: work around gcc false positive warning bug</title>
<updated>2021-09-30T08:09:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-09-20T17:26:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27f8c4402c4af24a261bf509338e98857002b14d'/>
<id>27f8c4402c4af24a261bf509338e98857002b14d</id>
<content type='text'>
commit d5f6545934c47e97c0b48a645418e877b452a992 upstream.

In commit b7213ffa0e58 ("qnx4: avoid stringop-overread errors") I tried
to teach gcc about how the directory entry structure can be two
different things depending on a status flag.  It made the code clearer,
and it seemed to make gcc happy.

However, Arnd points to a gcc bug, where despite using two different
members of a union, gcc then gets confused, and uses the size of one of
the members to decide if a string overrun happens.  And not necessarily
the rigth one.

End result: with some configurations, gcc-11 will still complain about
the source buffer size being overread:

  fs/qnx4/dir.c: In function 'qnx4_readdir':
  fs/qnx4/dir.c:76:32: error: 'strnlen' specified bound [16, 48] exceeds source size 1 [-Werror=stringop-overread]
     76 |                         size = strnlen(name, size);
        |                                ^~~~~~~~~~~~~~~~~~~
  fs/qnx4/dir.c:26:22: note: source object declared here
     26 |                 char de_name;
        |                      ^~~~~~~

because gcc will get confused about which union member entry is actually
getting accessed, even when the source code is very clear about it.  Gcc
internally will have combined two "redundant" pointers (pointing to
different union elements that are at the same offset), and takes the
size checking from one or the other - not necessarily the right one.

This is clearly a gcc bug, but we can work around it fairly easily.  The
biggest thing here is the big honking comment about why we do what we
do.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6
Reported-and-tested-by: Arnd Bergmann &lt;arnd@kernel.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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d5f6545934c47e97c0b48a645418e877b452a992 upstream.

In commit b7213ffa0e58 ("qnx4: avoid stringop-overread errors") I tried
to teach gcc about how the directory entry structure can be two
different things depending on a status flag.  It made the code clearer,
and it seemed to make gcc happy.

However, Arnd points to a gcc bug, where despite using two different
members of a union, gcc then gets confused, and uses the size of one of
the members to decide if a string overrun happens.  And not necessarily
the rigth one.

End result: with some configurations, gcc-11 will still complain about
the source buffer size being overread:

  fs/qnx4/dir.c: In function 'qnx4_readdir':
  fs/qnx4/dir.c:76:32: error: 'strnlen' specified bound [16, 48] exceeds source size 1 [-Werror=stringop-overread]
     76 |                         size = strnlen(name, size);
        |                                ^~~~~~~~~~~~~~~~~~~
  fs/qnx4/dir.c:26:22: note: source object declared here
     26 |                 char de_name;
        |                      ^~~~~~~

because gcc will get confused about which union member entry is actually
getting accessed, even when the source code is very clear about it.  Gcc
internally will have combined two "redundant" pointers (pointing to
different union elements that are at the same offset), and takes the
size checking from one or the other - not necessarily the right one.

This is clearly a gcc bug, but we can work around it fairly easily.  The
biggest thing here is the big honking comment about why we do what we
do.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99578#c6
Reported-and-tested-by: Arnd Bergmann &lt;arnd@kernel.org&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>qnx4: avoid stringop-overread errors</title>
<updated>2021-09-30T08:09:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-09-15T20:56:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8cd34eb616d97add9a707e1fca19b5deeb7dc46f'/>
<id>8cd34eb616d97add9a707e1fca19b5deeb7dc46f</id>
<content type='text'>
[ Upstream commit b7213ffa0e585feb1aee3e7173e965e66ee0abaa ]

The qnx4 directory entries are 64-byte blocks that have different
contents depending on the a status byte that is in the last byte of the
block.

In particular, a directory entry can be either a "link info" entry with
a 48-byte name and pointers to the real inode information, or an "inode
entry" with a smaller 16-byte name and the full inode information.

But the code was written to always just treat the directory name as if
it was part of that "inode entry", and just extend the name to the
longer case if the status byte said it was a link entry.

That work just fine and gives the right results, but now that gcc is
tracking data structure accesses much more, the code can trigger a
compiler error about using up to 48 bytes (the long name) in a structure
that only has that shorter name in it:

   fs/qnx4/dir.c: In function ‘qnx4_readdir’:
   fs/qnx4/dir.c:51:32: error: ‘strnlen’ specified bound 48 exceeds source size 16 [-Werror=stringop-overread]
      51 |                         size = strnlen(de-&gt;di_fname, size);
         |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from fs/qnx4/qnx4.h:3,
                    from fs/qnx4/dir.c:16:
   include/uapi/linux/qnx4_fs.h:45:25: note: source object declared here
      45 |         char            di_fname[QNX4_SHORT_NAME_MAX];
         |                         ^~~~~~~~

which is because the source code doesn't really make this whole "one of
two different types" explicit.

Fix this by introducing a very explicit union of the two types, and
basically explaining to the compiler what is really going on.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.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 b7213ffa0e585feb1aee3e7173e965e66ee0abaa ]

The qnx4 directory entries are 64-byte blocks that have different
contents depending on the a status byte that is in the last byte of the
block.

In particular, a directory entry can be either a "link info" entry with
a 48-byte name and pointers to the real inode information, or an "inode
entry" with a smaller 16-byte name and the full inode information.

But the code was written to always just treat the directory name as if
it was part of that "inode entry", and just extend the name to the
longer case if the status byte said it was a link entry.

That work just fine and gives the right results, but now that gcc is
tracking data structure accesses much more, the code can trigger a
compiler error about using up to 48 bytes (the long name) in a structure
that only has that shorter name in it:

   fs/qnx4/dir.c: In function ‘qnx4_readdir’:
   fs/qnx4/dir.c:51:32: error: ‘strnlen’ specified bound 48 exceeds source size 16 [-Werror=stringop-overread]
      51 |                         size = strnlen(de-&gt;di_fname, size);
         |                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from fs/qnx4/qnx4.h:3,
                    from fs/qnx4/dir.c:16:
   include/uapi/linux/qnx4_fs.h:45:25: note: source object declared here
      45 |         char            di_fname[QNX4_SHORT_NAME_MAX];
         |                         ^~~~~~~~

which is because the source code doesn't really make this whole "one of
two different types" explicit.

Fix this by introducing a very explicit union of the two types, and
basically explaining to the compiler what is really going on.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
