<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/fs/overlayfs/inode.c, branch linux-6.4.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-6.4.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-6.4.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2023-07-19T14:37:00Z</updated>
<entry>
<title>ovl: fix null pointer dereference in ovl_get_acl_rcu()</title>
<updated>2023-07-19T14:37:00Z</updated>
<author>
<name>Zhihao Cheng</name>
</author>
<published>2023-05-16T14:16:19Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=d536af163c53ce9f9bcfe87d2e9946f06f1a7ea4'/>
<id>urn:sha1:d536af163c53ce9f9bcfe87d2e9946f06f1a7ea4</id>
<content type='text'>
commit f4e19e595cc2e76a8a58413eb19d3d9c51328b53 upstream.

Following process:
         P1                     P2
 path_openat
  link_path_walk
   may_lookup
    inode_permission(rcu)
     ovl_permission
      acl_permission_check
       check_acl
        get_cached_acl_rcu
	 ovl_get_inode_acl
	  realinode = ovl_inode_real(ovl_inode)
	                      drop_cache
		               __dentry_kill(ovl_dentry)
				iput(ovl_inode)
		                 ovl_destroy_inode(ovl_inode)
		                  dput(oi-&gt;__upperdentry)
		                   dentry_kill(upperdentry)
		                    dentry_unlink_inode
				     upperdentry-&gt;d_inode = NULL
	    ovl_inode_upper
	     upperdentry = ovl_i_dentry_upper(ovl_inode)
	     d_inode(upperdentry) // returns NULL
	  IS_POSIXACL(realinode) // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
  [  205.472797] BUG: kernel NULL pointer dereference, address:
                 0000000000000028
  [  205.476701] CPU: 2 PID: 2713 Comm: ls Not tainted
                 6.3.0-12064-g2edfa098e750-dirty #1216
  [  205.478754] RIP: 0010:do_ovl_get_acl+0x5d/0x300
  [  205.489584] Call Trace:
  [  205.489812]  &lt;TASK&gt;
  [  205.490014]  ovl_get_inode_acl+0x26/0x30
  [  205.490466]  get_cached_acl_rcu+0x61/0xa0
  [  205.490908]  generic_permission+0x1bf/0x4e0
  [  205.491447]  ovl_permission+0x79/0x1b0
  [  205.491917]  inode_permission+0x15e/0x2c0
  [  205.492425]  link_path_walk+0x115/0x550
  [  205.493311]  path_lookupat.isra.0+0xb2/0x200
  [  205.493803]  filename_lookup+0xda/0x240
  [  205.495747]  vfs_fstatat+0x7b/0xb0

Fetch a reproducer in [Link].

Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217404
Fixes: 332f606b32b6 ("ovl: enable RCU'd -&gt;get_acl()")
Cc: &lt;stable@vger.kernel.org&gt; # v5.15
Signed-off-by: Zhihao Cheng &lt;chengzhihao1@huawei.com&gt;
Suggested-by: Christian Brauner &lt;brauner@kernel.org&gt;
Suggested-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ovl: fix null pointer dereference in ovl_permission()</title>
<updated>2023-07-19T14:37:00Z</updated>
<author>
<name>Zhihao Cheng</name>
</author>
<published>2023-05-16T14:16:18Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=69f9ae7edf9ec0ff500429101923347fcba5c8c4'/>
<id>urn:sha1:69f9ae7edf9ec0ff500429101923347fcba5c8c4</id>
<content type='text'>
commit 1a73f5b8f079fd42a544c1600beface50c63af7c upstream.

Following process:
          P1                     P2
 path_lookupat
  link_path_walk
   inode_permission
    ovl_permission
      ovl_i_path_real(inode, &amp;realpath)
        path-&gt;dentry = ovl_i_dentry_upper(inode)
                          drop_cache
			   __dentry_kill(ovl_dentry)
		            iput(ovl_inode)
		             ovl_destroy_inode(ovl_inode)
		              dput(oi-&gt;__upperdentry)
		               dentry_kill(upperdentry)
		                dentry_unlink_inode
				 upperdentry-&gt;d_inode = NULL
      realinode = d_inode(realpath.dentry) // return NULL
      inode_permission(realinode)
       inode-&gt;i_sb  // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
  [  335.664979] BUG: kernel NULL pointer dereference,
                 address: 0000000000000002
  [  335.668032] CPU: 0 PID: 2592 Comm: ls Not tainted 6.3.0
  [  335.669956] RIP: 0010:inode_permission+0x33/0x2c0
  [  335.678939] Call Trace:
  [  335.679165]  &lt;TASK&gt;
  [  335.679371]  ovl_permission+0xde/0x320
  [  335.679723]  inode_permission+0x15e/0x2c0
  [  335.680090]  link_path_walk+0x115/0x550
  [  335.680771]  path_lookupat.isra.0+0xb2/0x200
  [  335.681170]  filename_lookup+0xda/0x240
  [  335.681922]  vfs_statx+0xa6/0x1f0
  [  335.682233]  vfs_fstatat+0x7b/0xb0

Fetch a reproducer in [Link].

Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217405
Fixes: 4b7791b2e958 ("ovl: handle idmappings in ovl_permission()")
Cc: &lt;stable@vger.kernel.org&gt; # v5.19
Signed-off-by: Zhihao Cheng &lt;chengzhihao1@huawei.com&gt;
Suggested-by: Christian Brauner &lt;brauner@kernel.org&gt;
Suggested-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>fs: port vfs{g,u}id helpers to mnt_idmap</title>
<updated>2023-01-19T08:24:30Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:32Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4d7ca4090184c153f8ccb1a68ca5cf136dac108b'/>
<id>urn:sha1:4d7ca4090184c153f8ccb1a68ca5cf136dac108b</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port privilege checking helpers to mnt_idmap</title>
<updated>2023-01-19T08:24:29Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:27Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=9452e93e6dae862d7aeff2b11236d79bde6f9b66'/>
<id>urn:sha1:9452e93e6dae862d7aeff2b11236d79bde6f9b66</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port inode_owner_or_capable() to mnt_idmap</title>
<updated>2023-01-19T08:24:29Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:26Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=01beba7957a26f9b7179127e8ad56bb5a0f56138'/>
<id>urn:sha1:01beba7957a26f9b7179127e8ad56bb5a0f56138</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port -&gt;permission() to pass mnt_idmap</title>
<updated>2023-01-19T08:24:28Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:22Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4609e1f18e19c3b302e1eb4858334bca1532f780'/>
<id>urn:sha1:4609e1f18e19c3b302e1eb4858334bca1532f780</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port -&gt;fileattr_set() to pass mnt_idmap</title>
<updated>2023-01-19T08:24:27Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:21Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=8782a9aea3ab4d697ad67d1f8ebca38a4e1c24ab'/>
<id>urn:sha1:8782a9aea3ab4d697ad67d1f8ebca38a4e1c24ab</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port -&gt;set_acl() to pass mnt_idmap</title>
<updated>2023-01-19T08:24:27Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:20Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=13e83a4923bea7c4f2f6714030cb7e56d20ef7e5'/>
<id>urn:sha1:13e83a4923bea7c4f2f6714030cb7e56d20ef7e5</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port -&gt;get_acl() to pass mnt_idmap</title>
<updated>2023-01-19T08:24:27Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:19Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=77435322777d8a8a08264a39111bef94e32b871b'/>
<id>urn:sha1:77435322777d8a8a08264a39111bef94e32b871b</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
<entry>
<title>fs: port -&gt;getattr() to pass mnt_idmap</title>
<updated>2023-01-19T08:24:25Z</updated>
<author>
<name>Christian Brauner</name>
</author>
<published>2023-01-13T11:49:12Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=b74d24f7a74ffd2d42ca883d84b7422b8d545901'/>
<id>urn:sha1:b74d24f7a74ffd2d42ca883d84b7422b8d545901</id>
<content type='text'>
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner &lt;dchinner@redhat.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Christian Brauner (Microsoft) &lt;brauner@kernel.org&gt;
</content>
</entry>
</feed>
