<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/fs/netfs, branch linux-6.11.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>netfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING</title>
<updated>2024-12-05T12:52:47+00:00</updated>
<author>
<name>Zizhi Wo</name>
<email>wozizhi@huawei.com</email>
</author>
<published>2024-11-07T11:06:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8beb682cc9a0798a280bbb95e3e41617237090b2'/>
<id>8beb682cc9a0798a280bbb95e3e41617237090b2</id>
<content type='text'>
[ Upstream commit 22f9400a6f3560629478e0a64247b8fcc811a24d ]

In fscache_create_volume(), there is a missing memory barrier between the
bit-clearing operation and the wake-up operation. This may cause a
situation where, after a wake-up, the bit-clearing operation hasn't been
detected yet, leading to an indefinite wait. The triggering process is as
follows:

  [cookie1]                [cookie2]                  [volume_work]
fscache_perform_lookup
  fscache_create_volume
                        fscache_perform_lookup
                          fscache_create_volume
			                        fscache_create_volume_work
                                                  cachefiles_acquire_volume
                                                  clear_and_wake_up_bit
    test_and_set_bit
                            test_and_set_bit
                              goto maybe_wait
      goto no_wait

In the above process, cookie1 and cookie2 has the same volume. When cookie1
enters the -no_wait- process, it will clear the bit and wake up the waiting
process. If a barrier is missing, it may cause cookie2 to remain in the
-wait- process indefinitely.

In commit 3288666c7256 ("fscache: Use clear_and_wake_up_bit() in
fscache_create_volume_work()"), barriers were added to similar operations
in fscache_create_volume_work(), but fscache_create_volume() was missed.

By combining the clear and wake operations into clear_and_wake_up_bit() to
fix this issue.

Fixes: bfa22da3ed65 ("fscache: Provide and use cache methods to lookup/create/free a volume")
Signed-off-by: Zizhi Wo &lt;wozizhi@huawei.com&gt;
Link: https://lore.kernel.org/r/20241107110649.3980193-6-wozizhi@huawei.com
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.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 22f9400a6f3560629478e0a64247b8fcc811a24d ]

In fscache_create_volume(), there is a missing memory barrier between the
bit-clearing operation and the wake-up operation. This may cause a
situation where, after a wake-up, the bit-clearing operation hasn't been
detected yet, leading to an indefinite wait. The triggering process is as
follows:

  [cookie1]                [cookie2]                  [volume_work]
fscache_perform_lookup
  fscache_create_volume
                        fscache_perform_lookup
                          fscache_create_volume
			                        fscache_create_volume_work
                                                  cachefiles_acquire_volume
                                                  clear_and_wake_up_bit
    test_and_set_bit
                            test_and_set_bit
                              goto maybe_wait
      goto no_wait

In the above process, cookie1 and cookie2 has the same volume. When cookie1
enters the -no_wait- process, it will clear the bit and wake up the waiting
process. If a barrier is missing, it may cause cookie2 to remain in the
-wait- process indefinitely.

In commit 3288666c7256 ("fscache: Use clear_and_wake_up_bit() in
fscache_create_volume_work()"), barriers were added to similar operations
in fscache_create_volume_work(), but fscache_create_volume() was missed.

By combining the clear and wake operations into clear_and_wake_up_bit() to
fix this issue.

Fixes: bfa22da3ed65 ("fscache: Provide and use cache methods to lookup/create/free a volume")
Signed-off-by: Zizhi Wo &lt;wozizhi@huawei.com&gt;
Link: https://lore.kernel.org/r/20241107110649.3980193-6-wozizhi@huawei.com
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfs: Downgrade i_rwsem for a buffered write</title>
<updated>2024-11-17T14:09:53+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2024-10-16T16:28:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e58a012d9889f644e598cd299b46892312c4c01'/>
<id>4e58a012d9889f644e598cd299b46892312c4c01</id>
<content type='text'>
[ Upstream commit d6a77668a708f0b5ca6713b39c178c9d9563c35b ]

In the I/O locking code borrowed from NFS into netfslib, i_rwsem is held
locked across a buffered write - but this causes a performance regression
in cifs as it excludes buffered reads for the duration (cifs didn't use any
locking for buffered reads).

Mitigate this somewhat by downgrading the i_rwsem to a read lock across the
buffered write.  This at least allows parallel reads to occur whilst
excluding other writes, DIO, truncate and setattr.

Note that this shouldn't be a problem for a buffered write as a read
through an mmap can circumvent i_rwsem anyway.

Also note that we might want to make this change in NFS also.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Link: https://lore.kernel.org/r/1317958.1729096113@warthog.procyon.org.uk
cc: Steve French &lt;sfrench@samba.org&gt;
cc: Paulo Alcantara &lt;pc@manguebit.com&gt;
cc: Trond Myklebust &lt;trondmy@kernel.org&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: netfs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.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 d6a77668a708f0b5ca6713b39c178c9d9563c35b ]

In the I/O locking code borrowed from NFS into netfslib, i_rwsem is held
locked across a buffered write - but this causes a performance regression
in cifs as it excludes buffered reads for the duration (cifs didn't use any
locking for buffered reads).

Mitigate this somewhat by downgrading the i_rwsem to a read lock across the
buffered write.  This at least allows parallel reads to occur whilst
excluding other writes, DIO, truncate and setattr.

Note that this shouldn't be a problem for a buffered write as a read
through an mmap can circumvent i_rwsem anyway.

Also note that we might want to make this change in NFS also.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Link: https://lore.kernel.org/r/1317958.1729096113@warthog.procyon.org.uk
cc: Steve French &lt;sfrench@samba.org&gt;
cc: Paulo Alcantara &lt;pc@manguebit.com&gt;
cc: Trond Myklebust &lt;trondmy@kernel.org&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: netfs@lists.linux.dev
cc: linux-cifs@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfs: Cancel dirty folios that have no storage destination</title>
<updated>2024-10-10T10:03:18+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2024-07-29T11:23:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bfaaf21a5d326e6bd011a59a127eb1721552f477'/>
<id>bfaaf21a5d326e6bd011a59a127eb1721552f477</id>
<content type='text'>
[ Upstream commit 8f246b7c0a1be0882374f2ff831a61f0dbe77678 ]

Kafs wants to be able to cache the contents of directories (and symlinks),
but whilst these are downloaded from the server with the FS.FetchData RPC
op and similar, the same as for regular files, they can't be updated by
FS.StoreData, but rather have special operations (FS.MakeDir, etc.).

Now, rather than redownloading a directory's content after each change made
to that directory, kafs modifies the local blob.  This blob can be saved
out to the cache, and since it's using netfslib, kafs just marks the folios
dirty and lets -&gt;writepages() on the directory take care of it, as for an
regular file.

This is fine as long as there's a cache as although the upload stream is
disabled, there's a cache stream to drive the procedure.  But if the cache
goes away in the meantime, suddenly there's no way do any writes and the
code gets confused, complains "R=%x: No submit" to dmesg and leaves the
dirty folio hanging.

Fix this by just cancelling the store of the folio if neither stream is
active.  (If there's no cache at the time of dirtying, we should just not
mark the folio dirty).

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-23-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner &lt;brauner@kernel.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 8f246b7c0a1be0882374f2ff831a61f0dbe77678 ]

Kafs wants to be able to cache the contents of directories (and symlinks),
but whilst these are downloaded from the server with the FS.FetchData RPC
op and similar, the same as for regular files, they can't be updated by
FS.StoreData, but rather have special operations (FS.MakeDir, etc.).

Now, rather than redownloading a directory's content after each change made
to that directory, kafs modifies the local blob.  This blob can be saved
out to the cache, and since it's using netfslib, kafs just marks the folios
dirty and lets -&gt;writepages() on the directory take care of it, as for an
regular file.

This is fine as long as there's a cache as although the upload stream is
disabled, there's a cache stream to drive the procedure.  But if the cache
goes away in the meantime, suddenly there's no way do any writes and the
code gets confused, complains "R=%x: No submit" to dmesg and leaves the
dirty folio hanging.

Fix this by just cancelling the store of the folio if neither stream is
active.  (If there's no cache at the time of dirtying, we should just not
mark the folio dirty).

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-23-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfs: Fix missing wakeup after issuing writes</title>
<updated>2024-10-10T10:03:00+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2024-10-02T14:45:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2c1eabb461c2623c1fe26e2e0515c6e2cc5674cf'/>
<id>2c1eabb461c2623c1fe26e2e0515c6e2cc5674cf</id>
<content type='text'>
[ Upstream commit 1ca4169c391c370e0f3a92938df2862900575096 ]

After dividing up a proposed write into subrequests, netfslib sets
NETFS_RREQ_ALL_QUEUED to indicate to the collector that it can move on to
the final cleanup once it has emptied the subrequest queues.

Now, whilst the collector will normally end up running at least once after
this bit is set just because it takes a while to process all the write
subrequests before the collector runs out of subrequests, there exists the
possibility that the issuing thread will be forced to sleep and the
collector thread will clean up all the subrequests before ALL_QUEUED gets
set.

In such a case, the collector thread will not get triggered again and will
never clear NETFS_RREQ_IN_PROGRESS thus leaving a request uncompleted and
causing a potential futute hang.

Fix this by scheduling the write collector if all the subrequest queues are
empty (and thus no writes pending issuance).

Note that we'd do this ideally before queuing the subrequest, but in the
case of buffered writeback, at least, we can't find out that we've run out
of folios until after we've called writeback_iter() and it has returned
NULL - at which point we might not actually have any subrequests still
under construction.

Fixes: 288ace2f57c9 ("netfs: New writeback implementation")
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Link: https://lore.kernel.org/r/3317784.1727880350@warthog.procyon.org.uk
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.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 1ca4169c391c370e0f3a92938df2862900575096 ]

After dividing up a proposed write into subrequests, netfslib sets
NETFS_RREQ_ALL_QUEUED to indicate to the collector that it can move on to
the final cleanup once it has emptied the subrequest queues.

Now, whilst the collector will normally end up running at least once after
this bit is set just because it takes a while to process all the write
subrequests before the collector runs out of subrequests, there exists the
possibility that the issuing thread will be forced to sleep and the
collector thread will clean up all the subrequests before ALL_QUEUED gets
set.

In such a case, the collector thread will not get triggered again and will
never clear NETFS_RREQ_IN_PROGRESS thus leaving a request uncompleted and
causing a potential futute hang.

Fix this by scheduling the write collector if all the subrequest queues are
empty (and thus no writes pending issuance).

Note that we'd do this ideally before queuing the subrequest, but in the
case of buffered writeback, at least, we can't find out that we've run out
of folios until after we've called writeback_iter() and it has returned
NULL - at which point we might not actually have any subrequests still
under construction.

Fixes: 288ace2f57c9 ("netfs: New writeback implementation")
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Link: https://lore.kernel.org/r/3317784.1727880350@warthog.procyon.org.uk
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfs: Delete subtree of 'fs/netfs' when netfs module exits</title>
<updated>2024-10-04T14:38:49+00:00</updated>
<author>
<name>Baokun Li</name>
<email>libaokun1@huawei.com</email>
</author>
<published>2024-08-26T11:34:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7a9eaf97d56625e55b31a7beb558e1ee185ca461'/>
<id>7a9eaf97d56625e55b31a7beb558e1ee185ca461</id>
<content type='text'>
commit 3c58a9575e02c2b90a3180007d57105ceaa7c246 upstream.

In netfs_init() or fscache_proc_init(), we create dentry under 'fs/netfs',
but in netfs_exit(), we only delete the proc entry of 'fs/netfs' without
deleting its subtree. This triggers the following WARNING:

==================================================================
remove_proc_entry: removing non-empty directory 'fs/netfs', leaking at least 'requests'
WARNING: CPU: 4 PID: 566 at fs/proc/generic.c:717 remove_proc_entry+0x160/0x1c0
Modules linked in: netfs(-)
CPU: 4 UID: 0 PID: 566 Comm: rmmod Not tainted 6.11.0-rc3 #860
RIP: 0010:remove_proc_entry+0x160/0x1c0
Call Trace:
 &lt;TASK&gt;
 netfs_exit+0x12/0x620 [netfs]
 __do_sys_delete_module.isra.0+0x14c/0x2e0
 do_syscall_64+0x4b/0x110
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
==================================================================

Therefore use remove_proc_subtree() instead of remove_proc_entry() to
fix the above problem.

Fixes: 7eb5b3e3a0a5 ("netfs, fscache: Move /proc/fs/fscache to /proc/fs/netfs and put in a symlink")
Cc: stable@kernel.org
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240826113404.3214786-1-libaokun@huaweicloud.com
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@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 3c58a9575e02c2b90a3180007d57105ceaa7c246 upstream.

In netfs_init() or fscache_proc_init(), we create dentry under 'fs/netfs',
but in netfs_exit(), we only delete the proc entry of 'fs/netfs' without
deleting its subtree. This triggers the following WARNING:

==================================================================
remove_proc_entry: removing non-empty directory 'fs/netfs', leaking at least 'requests'
WARNING: CPU: 4 PID: 566 at fs/proc/generic.c:717 remove_proc_entry+0x160/0x1c0
Modules linked in: netfs(-)
CPU: 4 UID: 0 PID: 566 Comm: rmmod Not tainted 6.11.0-rc3 #860
RIP: 0010:remove_proc_entry+0x160/0x1c0
Call Trace:
 &lt;TASK&gt;
 netfs_exit+0x12/0x620 [netfs]
 __do_sys_delete_module.isra.0+0x14c/0x2e0
 do_syscall_64+0x4b/0x110
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
==================================================================

Therefore use remove_proc_subtree() instead of remove_proc_entry() to
fix the above problem.

Fixes: 7eb5b3e3a0a5 ("netfs, fscache: Move /proc/fs/fscache to /proc/fs/netfs and put in a symlink")
Cc: stable@kernel.org
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240826113404.3214786-1-libaokun@huaweicloud.com
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'v6.11-rc6-cifs-client-fixes' of git://git.samba.org/sfrench/cifs-2.6</title>
<updated>2024-09-07T00:30:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-07T00:30:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a86b83f77797ad1289601beb9a9ea61ad9f593cc'/>
<id>a86b83f77797ad1289601beb9a9ea61ad9f593cc</id>
<content type='text'>
Pull smb client fixes from Steve French:

 - fix potential mount hang

 - fix retry problem in two types of compound operations

 - important netfs integration fix in SMB1 read paths

 - fix potential uninitialized zero point of inode

 - minor patch to improve debugging for potential crediting problems

* tag 'v6.11-rc6-cifs-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  netfs, cifs: Improve some debugging bits
  cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3
  cifs: Fix zero_point init on inode initialisation
  smb: client: fix double put of @cfile in smb2_set_path_size()
  smb: client: fix double put of @cfile in smb2_rename_path()
  smb: client: fix hang in wait_for_response() for negproto
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull smb client fixes from Steve French:

 - fix potential mount hang

 - fix retry problem in two types of compound operations

 - important netfs integration fix in SMB1 read paths

 - fix potential uninitialized zero point of inode

 - minor patch to improve debugging for potential crediting problems

* tag 'v6.11-rc6-cifs-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  netfs, cifs: Improve some debugging bits
  cifs: Fix SMB1 readv/writev callback in the same way as SMB2/3
  cifs: Fix zero_point init on inode initialisation
  smb: client: fix double put of @cfile in smb2_set_path_size()
  smb: client: fix double put of @cfile in smb2_rename_path()
  smb: client: fix hang in wait_for_response() for negproto
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'vfs-6.11-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2024-09-04T16:33:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-04T16:33:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4356ab331c8f0dbed0f683abde345cd5503db1e4'/>
<id>4356ab331c8f0dbed0f683abde345cd5503db1e4</id>
<content type='text'>
Pull vfs fixes from Christian Brauner:
 "Two netfs fixes for this merge window:

   - Ensure that fscache_cookie_lru_time is deleted when the fscache
     module is removed to prevent UAF

   - Fix filemap_invalidate_inode() to use invalidate_inode_pages2_range()

     Before it used truncate_inode_pages_partial() which causes
     copy_file_range() to fail on cifs"

* tag 'vfs-6.11-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF
  mm: Fix filemap_invalidate_inode() to use invalidate_inode_pages2_range()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull vfs fixes from Christian Brauner:
 "Two netfs fixes for this merge window:

   - Ensure that fscache_cookie_lru_time is deleted when the fscache
     module is removed to prevent UAF

   - Fix filemap_invalidate_inode() to use invalidate_inode_pages2_range()

     Before it used truncate_inode_pages_partial() which causes
     copy_file_range() to fail on cifs"

* tag 'vfs-6.11-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF
  mm: Fix filemap_invalidate_inode() to use invalidate_inode_pages2_range()
</pre>
</div>
</content>
</entry>
<entry>
<title>netfs, cifs: Improve some debugging bits</title>
<updated>2024-09-03T15:17:51+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2024-08-23T13:36:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ab85218910729b95f9b0acfebab55c2cab5f8ee7'/>
<id>ab85218910729b95f9b0acfebab55c2cab5f8ee7</id>
<content type='text'>
Improve some debugging bits:

 (1) The netfslib _debug() macro doesn't need a newline in its format
     string.

 (2) Display the request debug ID and subrequest index in messages emitted
     in smb2_adjust_credits() to make it easier to reference in traces.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Steve French &lt;sfrench@samba.org&gt;
cc: Paulo Alcantara &lt;pc@manguebit.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Improve some debugging bits:

 (1) The netfslib _debug() macro doesn't need a newline in its format
     string.

 (2) Display the request debug ID and subrequest index in messages emitted
     in smb2_adjust_credits() to make it easier to reference in traces.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Steve French &lt;sfrench@samba.org&gt;
cc: Paulo Alcantara &lt;pc@manguebit.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fscache: delete fscache_cookie_lru_timer when fscache exits to avoid UAF</title>
<updated>2024-09-01T08:30:25+00:00</updated>
<author>
<name>Baokun Li</name>
<email>libaokun1@huawei.com</email>
</author>
<published>2024-08-26T11:20:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f'/>
<id>72a6e22c604c95ddb3b10b5d3bb85b6ff4dbc34f</id>
<content type='text'>
The fscache_cookie_lru_timer is initialized when the fscache module
is inserted, but is not deleted when the fscache module is removed.
If timer_reduce() is called before removing the fscache module,
the fscache_cookie_lru_timer will be added to the timer list of
the current cpu. Afterwards, a use-after-free will be triggered
in the softIRQ after removing the fscache module, as follows:

==================================================================
BUG: unable to handle page fault for address: fffffbfff803c9e9
 PF: supervisor read access in kernel mode
 PF: error_code(0x0000) - not-present page
PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855
Tainted: [W]=WARN
RIP: 0010:__run_timer_base.part.0+0x254/0x8a0
Call Trace:
 &lt;IRQ&gt;
 tmigr_handle_remote_up+0x627/0x810
 __walk_groups.isra.0+0x47/0x140
 tmigr_handle_remote+0x1fa/0x2f0
 handle_softirqs+0x180/0x590
 irq_exit_rcu+0x84/0xb0
 sysvec_apic_timer_interrupt+0x6e/0x90
 &lt;/IRQ&gt;
 &lt;TASK&gt;
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
 default_idle_call+0x38/0x60
 do_idle+0x2b5/0x300
 cpu_startup_entry+0x54/0x60
 start_secondary+0x20d/0x280
 common_startup_64+0x13e/0x148
 &lt;/TASK&gt;
Modules linked in: [last unloaded: netfs]
==================================================================

Therefore delete fscache_cookie_lru_timer when removing the fscahe module.

Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning")
Cc: stable@kernel.org
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240826112056.2458299-1-libaokun@huaweicloud.com
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The fscache_cookie_lru_timer is initialized when the fscache module
is inserted, but is not deleted when the fscache module is removed.
If timer_reduce() is called before removing the fscache module,
the fscache_cookie_lru_timer will be added to the timer list of
the current cpu. Afterwards, a use-after-free will be triggered
in the softIRQ after removing the fscache module, as follows:

==================================================================
BUG: unable to handle page fault for address: fffffbfff803c9e9
 PF: supervisor read access in kernel mode
 PF: error_code(0x0000) - not-present page
PGD 21ffea067 P4D 21ffea067 PUD 21ffe6067 PMD 110a7c067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G W 6.11.0-rc3 #855
Tainted: [W]=WARN
RIP: 0010:__run_timer_base.part.0+0x254/0x8a0
Call Trace:
 &lt;IRQ&gt;
 tmigr_handle_remote_up+0x627/0x810
 __walk_groups.isra.0+0x47/0x140
 tmigr_handle_remote+0x1fa/0x2f0
 handle_softirqs+0x180/0x590
 irq_exit_rcu+0x84/0xb0
 sysvec_apic_timer_interrupt+0x6e/0x90
 &lt;/IRQ&gt;
 &lt;TASK&gt;
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:default_idle+0xf/0x20
 default_idle_call+0x38/0x60
 do_idle+0x2b5/0x300
 cpu_startup_entry+0x54/0x60
 start_secondary+0x20d/0x280
 common_startup_64+0x13e/0x148
 &lt;/TASK&gt;
Modules linked in: [last unloaded: netfs]
==================================================================

Therefore delete fscache_cookie_lru_timer when removing the fscahe module.

Fixes: 12bb21a29c19 ("fscache: Implement cookie user counting and resource pinning")
Cc: stable@kernel.org
Signed-off-by: Baokun Li &lt;libaokun1@huawei.com&gt;
Link: https://lore.kernel.org/r/20240826112056.2458299-1-libaokun@huaweicloud.com
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfs, cifs: Fix handling of short DIO read</title>
<updated>2024-08-28T12:47:36+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2024-08-22T22:06:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1da29f2c39b67b846b74205c81bf0ccd96d34727'/>
<id>1da29f2c39b67b846b74205c81bf0ccd96d34727</id>
<content type='text'>
Short DIO reads, particularly in relation to cifs, are not being handled
correctly by cifs and netfslib.  This can be tested by doing a DIO read of
a file where the size of read is larger than the size of the file.  When it
crosses the EOF, it gets a short read and this gets retried, and in the
case of cifs, the retry read fails, with the failure being translated to
ENODATA.

Fix this by the following means:

 (1) Add a flag, NETFS_SREQ_HIT_EOF, for the filesystem to set when it
     detects that the read did hit the EOF.

 (2) Make the netfslib read assessment stop processing subrequests when it
     encounters one with that flag set.

 (3) Return rreq-&gt;transferred, the accumulated contiguous amount read to
     that point, to userspace for a DIO read.

 (4) Make cifs set the flag and clear the error if the read RPC returned
     ENODATA.

 (5) Make cifs set the flag and clear the error if a short read occurred
     without error and the read-to file position is now at the remote inode
     size.

Fixes: 69c3c023af25 ("cifs: Implement netfslib hooks")
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Steve French &lt;sfrench@samba.org&gt;
cc: Paulo Alcantara &lt;pc@manguebit.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Short DIO reads, particularly in relation to cifs, are not being handled
correctly by cifs and netfslib.  This can be tested by doing a DIO read of
a file where the size of read is larger than the size of the file.  When it
crosses the EOF, it gets a short read and this gets retried, and in the
case of cifs, the retry read fails, with the failure being translated to
ENODATA.

Fix this by the following means:

 (1) Add a flag, NETFS_SREQ_HIT_EOF, for the filesystem to set when it
     detects that the read did hit the EOF.

 (2) Make the netfslib read assessment stop processing subrequests when it
     encounters one with that flag set.

 (3) Return rreq-&gt;transferred, the accumulated contiguous amount read to
     that point, to userspace for a DIO read.

 (4) Make cifs set the flag and clear the error if the read RPC returned
     ENODATA.

 (5) Make cifs set the flag and clear the error if a short read occurred
     without error and the read-to file position is now at the remote inode
     size.

Fixes: 69c3c023af25 ("cifs: Implement netfslib hooks")
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
cc: Steve French &lt;sfrench@samba.org&gt;
cc: Paulo Alcantara &lt;pc@manguebit.com&gt;
cc: Jeff Layton &lt;jlayton@kernel.org&gt;
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French &lt;stfrench@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
