History log of /linux-6.15/include/linux/posix_acl.h (Results 1 – 25 of 51)
Revision (<<< Hide revision tags) (Show revision tags >>>) Date Author Comments
Revision tags: v6.15, v6.15-rc7, v6.15-rc6, v6.15-rc5, v6.15-rc4, v6.15-rc3, v6.15-rc2, v6.15-rc1, v6.14, v6.14-rc7, v6.14-rc6, v6.14-rc5, v6.14-rc4, v6.14-rc3, v6.14-rc2
# dfd500d8 04-Feb-2025 Gustavo A. R. Silva <[email protected]>

fs: nfs: acl: Avoid -Wflex-array-member-not-at-end warning

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

So, in order to avoid ending up

fs: nfs: acl: Avoid -Wflex-array-member-not-at-end warning

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

So, in order to avoid ending up with a flexible-array member in the
middle of other structs, we use the `struct_group_tagged()` helper
to create a new tagged `struct posix_acl_hdr`. This structure
groups together all the members of the flexible `struct posix_acl`
except the flexible array.

As a result, the array is effectively separated from the rest of the
members without modifying the memory layout of the flexible structure.
We then change the type of the middle struct member currently causing
trouble from `struct posix_acl` to `struct posix_acl_hdr`.

We also want to ensure that when new members need to be added to the
flexible structure, they are always included within the newly created
tagged struct. For this, we use `static_assert()`. This ensures that the
memory layout for both the flexible structure and the new tagged struct
is the same after any changes.

This approach avoids having to implement `struct posix_acl_hdr` as a
completely separate structure, thus preventing having to maintain two
independent but basically identical structures, closing the door to
potential bugs in the future.

We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure, through which we can access the flexible-array
member, if necessary.

So, with these changes, fix the following warning:

fs/nfs_common/nfsacl.c:45:26: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <[email protected]>
Acked-by: Anna Schumaker <[email protected]>
Acked-by: Jeff Layton <[email protected]>
Signed-off-by: Chuck Lever <[email protected]>

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Revision tags: v6.14-rc1, v6.13, v6.13-rc7, v6.13-rc6, v6.13-rc5, v6.13-rc4, v6.13-rc3, v6.13-rc2, v6.13-rc1, v6.12, v6.12-rc7, v6.12-rc6, v6.12-rc5, v6.12-rc4
# 8c6e03ff 18-Oct-2024 Thorsten Blum <[email protected]>

acl: Annotate struct posix_acl with __counted_by()

Add the __counted_by compiler attribute to the flexible array member
a_entries to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG

acl: Annotate struct posix_acl with __counted_by()

Add the __counted_by compiler attribute to the flexible array member
a_entries to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Use struct_size() to calculate the number of bytes to allocate for new
and cloned acls and remove the local size variables.

Change the posix_acl_alloc() function parameter count from int to
unsigned int to match posix_acl's a_count data type. Add identifier
names to the function definition to silence two checkpatch warnings.

Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Thorsten Blum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Cc: Nathan Chancellor <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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# 99bdadbd 15-Oct-2024 Thorsten Blum <[email protected]>

acl: Realign struct posix_acl to save 8 bytes

Reduce posix_acl's struct size by 8 bytes by realigning its members.

Cc: Christian Brauner <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Si

acl: Realign struct posix_acl to save 8 bytes

Reduce posix_acl's struct size by 8 bytes by realigning its members.

Cc: Christian Brauner <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Signed-off-by: Thorsten Blum <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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Revision tags: v6.12-rc3, v6.12-rc2, v6.12-rc1, v6.11, v6.11-rc7, v6.11-rc6, v6.11-rc5, v6.11-rc4, v6.11-rc3, v6.11-rc2, v6.11-rc1, v6.10, v6.10-rc7, v6.10-rc6, v6.10-rc5, v6.10-rc4, v6.10-rc3, v6.10-rc2, v6.10-rc1, v6.9, v6.9-rc7, v6.9-rc6, v6.9-rc5, v6.9-rc4, v6.9-rc3, v6.9-rc2, v6.9-rc1, v6.8, v6.8-rc7, v6.8-rc6, v6.8-rc5, v6.8-rc4, v6.8-rc3, v6.8-rc2, v6.8-rc1, v6.7, v6.7-rc8, v6.7-rc7, v6.7-rc6, v6.7-rc5, v6.7-rc4, v6.7-rc3, v6.7-rc2, v6.7-rc1, v6.6, v6.6-rc7, v6.6-rc6, v6.6-rc5, v6.6-rc4, v6.6-rc3, v6.6-rc2, v6.6-rc1, v6.5, v6.5-rc7, v6.5-rc6, v6.5-rc5, v6.5-rc4, v6.5-rc3, v6.5-rc2, v6.5-rc1, v6.4, v6.4-rc7, v6.4-rc6, v6.4-rc5, v6.4-rc4, v6.4-rc3, v6.4-rc2, v6.4-rc1, v6.3, v6.3-rc7, v6.3-rc6, v6.3-rc5, v6.3-rc4, v6.3-rc3, v6.3-rc2, v6.3-rc1, v6.2, v6.2-rc8, v6.2-rc7
# f2620f16 01-Feb-2023 Christian Brauner <[email protected]>

xattr: simplify listxattr helpers

The generic_listxattr() and simple_xattr_list() helpers list xattrs and
contain duplicated code. Add two helpers that both generic_listxattr()
and simple_xattr_list

xattr: simplify listxattr helpers

The generic_listxattr() and simple_xattr_list() helpers list xattrs and
contain duplicated code. Add two helpers that both generic_listxattr()
and simple_xattr_list() can use.

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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Revision tags: v6.2-rc6, v6.2-rc5, v6.2-rc4
# 700b7940 13-Jan-2023 Christian Brauner <[email protected]>

fs: port acl to mnt_idmap

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 conversi

fs: port acl to mnt_idmap

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 <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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# 13e83a49 13-Jan-2023 Christian Brauner <[email protected]>

fs: port ->set_acl() to pass mnt_idmap

Convert to struct mnt_idmap.

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

fs: port ->set_acl() to pass mnt_idmap

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 <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

show more ...


# 77435322 13-Jan-2023 Christian Brauner <[email protected]>

fs: port ->get_acl() to pass mnt_idmap

Convert to struct mnt_idmap.

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

fs: port ->get_acl() to pass mnt_idmap

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 <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

show more ...


Revision tags: v6.2-rc3, v6.2-rc2, v6.2-rc1, v6.1, v6.1-rc8, v6.1-rc7, v6.1-rc6, v6.1-rc5, v6.1-rc4, v6.1-rc3, v6.1-rc2, v6.1-rc1, v6.0, v6.0-rc7
# aeb7f005 22-Sep-2022 Christian Brauner <[email protected]>

acl: add vfs_remove_acl()

In previous patches we implemented get and set inode operations for all
non-stacking filesystems that support posix acls but didn't yet
implement get and/or set acl inode o

acl: add vfs_remove_acl()

In previous patches we implemented get and set inode operations for all
non-stacking filesystems that support posix acls but didn't yet
implement get and/or set acl inode operations. This specifically
affected cifs and 9p.

Now we can build a posix acl api based solely on get and set inode
operations. We add a new vfs_remove_acl() api that can be used to set
posix acls. This finally removes all type unsafety and type conversion
issues explained in detail in [1] that we aim to get rid of.

After we finished building the vfs api we can switch stacking
filesystems to rely on the new posix api and then finally switch the
xattr system calls themselves to rely on the posix acl api.

Link: https://lore.kernel.org/all/[email protected] [1]
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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# 4f353ba4 22-Sep-2022 Christian Brauner <[email protected]>

acl: add vfs_get_acl()

In previous patches we implemented get and set inode operations for all
non-stacking filesystems that support posix acls but didn't yet
implement get and/or set acl inode oper

acl: add vfs_get_acl()

In previous patches we implemented get and set inode operations for all
non-stacking filesystems that support posix acls but didn't yet
implement get and/or set acl inode operations. This specifically
affected cifs and 9p.

Now we can build a posix acl api based solely on get and set inode
operations. We add a new vfs_get_acl() api that can be used to get posix
acls. This finally removes all type unsafety and type conversion issues
explained in detail in [1] that we aim to get rid of.

After we finished building the vfs api we can switch stacking
filesystems to rely on the new posix api and then finally switch the
xattr system calls themselves to rely on the posix acl api.

Link: https://lore.kernel.org/all/[email protected] [1]
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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# e4cc9163 22-Sep-2022 Christian Brauner <[email protected]>

acl: add vfs_set_acl()

In previous patches we implemented get and set inode operations for all
non-stacking filesystems that support posix acls but didn't yet
implement get and/or set acl inode oper

acl: add vfs_set_acl()

In previous patches we implemented get and set inode operations for all
non-stacking filesystems that support posix acls but didn't yet
implement get and/or set acl inode operations. This specifically
affected cifs and 9p.

Now we can build a posix acl api based solely on get and set inode
operations. We add a new vfs_set_acl() api that can be used to set posix
acls. This finally removes all type unsafety and type conversion issues
explained in detail in [1] that we aim to get rid of.

After we finished building the vfs api we can switch stacking
filesystems to rely on the new posix api and then finally switch the
xattr system calls themselves to rely on the posix acl api.

Link: https://lore.kernel.org/all/[email protected] [1]
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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# cac2f8b8 22-Sep-2022 Christian Brauner <[email protected]>

fs: rename current get acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acl

fs: rename current get acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

The current inode operation for getting posix acls takes an inode
argument but various filesystems (e.g., 9p, cifs, overlayfs) need access
to the dentry. In contrast to the ->set_acl() inode operation we cannot
simply extend ->get_acl() to take a dentry argument. The ->get_acl()
inode operation is called from:

acl_permission_check()
-> check_acl()
-> get_acl()

which is part of generic_permission() which in turn is part of
inode_permission(). Both generic_permission() and inode_permission() are
called in the ->permission() handler of various filesystems (e.g.,
overlayfs). So simply passing a dentry argument to ->get_acl() would
amount to also having to pass a dentry argument to ->permission(). We
should avoid this unnecessary change.

So instead of extending the existing inode operation rename it from
->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that
passes a dentry argument and which filesystems that need access to the
dentry can implement instead of ->get_inode_acl(). Filesystems like cifs
which allow setting and getting posix acls but not using them for
permission checking during lookup can simply not implement
->get_inode_acl().

This is intended to be a non-functional change.

Link: https://lore.kernel.org/all/[email protected] [1]
Suggested-by/Inspired-by: Christoph Hellwig <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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# 138060ba 23-Sep-2022 Christian Brauner <[email protected]>

fs: pass dentry to set acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acl

fs: pass dentry to set acl method

The current way of setting and getting posix acls through the generic
xattr interface is error prone and type unsafe. The vfs needs to
interpret and fixup posix acls before storing or reporting it to
userspace. Various hacks exist to make this work. The code is hard to
understand and difficult to maintain in it's current form. Instead of
making this work by hacking posix acls through xattr handlers we are
building a dedicated posix acl api around the get and set inode
operations. This removes a lot of hackiness and makes the codepaths
easier to maintain. A lot of background can be found in [1].

Since some filesystem rely on the dentry being available to them when
setting posix acls (e.g., 9p and cifs) they cannot rely on set acl inode
operation. But since ->set_acl() is required in order to use the generic
posix acl xattr handlers filesystems that do not implement this inode
operation cannot use the handler and need to implement their own
dedicated posix acl handlers.

Update the ->set_acl() inode method to take a dentry argument. This
allows all filesystems to rely on ->set_acl().

As far as I can tell all codepaths can be switched to rely on the dentry
instead of just the inode. Note that the original motivation for passing
the dentry separate from the inode instead of just the dentry in the
xattr handlers was because of security modules that call
security_d_instantiate(). This hook is called during
d_instantiate_new(), d_add(), __d_instantiate_anon(), and
d_splice_alias() to initialize the inode's security context and possibly
to set security.* xattrs. Since this only affects security.* xattrs this
is completely irrelevant for posix acls.

Link: https://lore.kernel.org/all/[email protected] [1]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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Revision tags: v6.0-rc6, v6.0-rc5, v6.0-rc4, v6.0-rc3, v6.0-rc2, v6.0-rc1, v5.19, v5.19-rc8, v5.19-rc7, v5.19-rc6
# 8043bffd 06-Jul-2022 Christian Brauner <[email protected]>

acl: make posix_acl_clone() available to overlayfs

The ovl_get_acl() function needs to alter the POSIX ACLs retrieved from the
lower filesystem. Instead of hand-rolling a overlayfs specific
posix_ac

acl: make posix_acl_clone() available to overlayfs

The ovl_get_acl() function needs to alter the POSIX ACLs retrieved from the
lower filesystem. Instead of hand-rolling a overlayfs specific
posix_acl_clone() variant allow export it. It's not special and it's not deeply
internal anyway.

Link: https://lore.kernel.org/r/[email protected]
Cc: Seth Forshee <[email protected]>
Cc: Amir Goldstein <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Aleksa Sarai <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Cc: [email protected]
Cc: [email protected]
Reviewed-by: Seth Forshee <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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Revision tags: v5.19-rc5, v5.19-rc4, v5.19-rc3, v5.19-rc2, v5.19-rc1, v5.18, v5.18-rc7, v5.18-rc6, v5.18-rc5, v5.18-rc4, v5.18-rc3, v5.18-rc2, v5.18-rc1, v5.17, v5.17-rc8, v5.17-rc7, v5.17-rc6, v5.17-rc5, v5.17-rc4, v5.17-rc3, v5.17-rc2, v5.17-rc1, v5.16, v5.16-rc8, v5.16-rc7, v5.16-rc6, v5.16-rc5, v5.16-rc4, v5.16-rc3, v5.16-rc2, v5.16-rc1, v5.15, v5.15-rc7, v5.15-rc6, v5.15-rc5, v5.15-rc4, v5.15-rc3, v5.15-rc2, v5.15-rc1, v5.14, v5.14-rc7
# 332f606b 18-Aug-2021 Miklos Szeredi <[email protected]>

ovl: enable RCU'd ->get_acl()

Overlayfs does not cache ACL's (to avoid double caching). Instead it just
calls the underlying filesystem's i_op->get_acl(), which will return the
cached value, if pos

ovl: enable RCU'd ->get_acl()

Overlayfs does not cache ACL's (to avoid double caching). Instead it just
calls the underlying filesystem's i_op->get_acl(), which will return the
cached value, if possible.

In rcu path walk, however, get_cached_acl_rcu() is employed to get the
value from the cache, which will fail on overlayfs resulting in dropping
out of rcu walk mode. This can result in a big performance hit in certain
situations.

Fix by calling ->get_acl() with rcu=true in case of ACL_DONT_CACHE (which
indicates pass-through)

Reported-by: garyhuang <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

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Revision tags: v5.14-rc6, v5.14-rc5, v5.14-rc4, v5.14-rc3, v5.14-rc2, v5.14-rc1, v5.13, v5.13-rc7, v5.13-rc6, v5.13-rc5, v5.13-rc4, v5.13-rc3, v5.13-rc2, v5.13-rc1, v5.12, v5.12-rc8, v5.12-rc7, v5.12-rc6, v5.12-rc5, v5.12-rc4, v5.12-rc3, v5.12-rc2, v5.12-rc1, v5.12-rc1-dontuse, v5.11, v5.11-rc7, v5.11-rc6, v5.11-rc5
# 549c7297 21-Jan-2021 Christian Brauner <[email protected]>

fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has b

fs: make helpers idmap mount aware

Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/[email protected]
Cc: Christoph Hellwig <[email protected]>
Cc: David Howells <[email protected]>
Cc: Al Viro <[email protected]>
Cc: [email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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# e65ce2a5 21-Jan-2021 Christian Brauner <[email protected]>

acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it

acl: handle idmapped mounts

The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.

The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.

In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.

Link: https://lore.kernel.org/r/[email protected]
Cc: Christoph Hellwig <[email protected]>
Cc: David Howells <[email protected]>
Cc: Al Viro <[email protected]>
Cc: [email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...


# 47291baa 21-Jan-2021 Christian Brauner <[email protected]>

namei: make permission helpers idmapped mount aware

The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller

namei: make permission helpers idmapped mount aware

The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). If the
initial user namespace is passed nothing changes so non-idmapped mounts
will see identical behavior as before.

Link: https://lore.kernel.org/r/[email protected]
Cc: Christoph Hellwig <[email protected]>
Cc: David Howells <[email protected]>
Cc: Al Viro <[email protected]>
Cc: [email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: James Morris <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

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Revision tags: v5.11-rc4, v5.11-rc3, v5.11-rc2, v5.11-rc1, v5.10, v5.10-rc7, v5.10-rc6, v5.10-rc5, v5.10-rc4, v5.10-rc3, v5.10-rc2, v5.10-rc1, v5.9, v5.9-rc8, v5.9-rc7, v5.9-rc6, v5.9-rc5, v5.9-rc4, v5.9-rc3, v5.9-rc2, v5.9-rc1, v5.8, v5.8-rc7, v5.8-rc6, v5.8-rc5, v5.8-rc4, v5.8-rc3, v5.8-rc2, v5.8-rc1, v5.7, v5.7-rc7, v5.7-rc6, v5.7-rc5, v5.7-rc4, v5.7-rc3, v5.7-rc2, v5.7-rc1, v5.6
# 70f1451e 24-Mar-2020 Gustavo A. R. Silva <[email protected]>

posix_acl.h: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to decla

posix_acl.h: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <[email protected]>

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Revision tags: v5.6-rc7, v5.6-rc6, v5.6-rc5, v5.6-rc4, v5.6-rc3, v5.6-rc2, v5.6-rc1, v5.5, v5.5-rc7, v5.5-rc6, v5.5-rc5, v5.5-rc4, v5.5-rc3, v5.5-rc2, v5.5-rc1, v5.4, v5.4-rc8, v5.4-rc7, v5.4-rc6, v5.4-rc5, v5.4-rc4, v5.4-rc3, v5.4-rc2, v5.4-rc1, v5.3, v5.3-rc8, v5.3-rc7, v5.3-rc6, v5.3-rc5, v5.3-rc4, v5.3-rc3, v5.3-rc2, v5.3-rc1, v5.2, v5.2-rc7, v5.2-rc6, v5.2-rc5, v5.2-rc4, v5.2-rc3, v5.2-rc2, v5.2-rc1, v5.1, v5.1-rc7, v5.1-rc6, v5.1-rc5, v5.1-rc4, v5.1-rc3, v5.1-rc2, v5.1-rc1, v5.0, v5.0-rc8, v5.0-rc7, v5.0-rc6, v5.0-rc5, v5.0-rc4, v5.0-rc3, v5.0-rc2, v5.0-rc1, v4.20, v4.20-rc7, v4.20-rc6, v4.20-rc5, v4.20-rc4, v4.20-rc3, v4.20-rc2, v4.20-rc1, v4.19, v4.19-rc8, v4.19-rc7, v4.19-rc6, v4.19-rc5, v4.19-rc4, v4.19-rc3, v4.19-rc2, v4.19-rc1, v4.18, v4.18-rc8, v4.18-rc7, v4.18-rc6, v4.18-rc5, v4.18-rc4, v4.18-rc3, v4.18-rc2, v4.18-rc1, v4.17, v4.17-rc7, v4.17-rc6, v4.17-rc5, v4.17-rc4, v4.17-rc3, v4.17-rc2, v4.17-rc1, v4.16, v4.16-rc7, v4.16-rc6, v4.16-rc5, v4.16-rc4, v4.16-rc3, v4.16-rc2, v4.16-rc1, v4.15, v4.15-rc9, v4.15-rc8, v4.15-rc7, v4.15-rc6, v4.15-rc5, v4.15-rc4, v4.15-rc3, v4.15-rc2
# 66717260 29-Nov-2017 Elena Reshetova <[email protected]>

posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t

atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to

posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t

atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable posix_acl.a_refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

**Important note for maintainers:

Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts.
The full comparison can be seen in
https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon
in state to be merged to the documentation tree.
Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.

For the posix_acl.a_refcount it might make a difference
in following places:
- get_cached_acl(): increment in refcount_inc_not_zero() only
guarantees control dependency on success vs. fully ordered
atomic counterpart. However this operation is performed under
rcu_read_lock(), so this should be fine.
- posix_acl_release(): decrement in refcount_dec_and_test() only
provides RELEASE ordering and control dependency on success
vs. fully ordered atomic counterpart

Suggested-by: Kees Cook <[email protected]>
Reviewed-by: David Windsor <[email protected]>
Reviewed-by: Hans Liljestrand <[email protected]>
Signed-off-by: Elena Reshetova <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>

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Revision tags: v4.15-rc1, v4.14, v4.14-rc8
# b2441318 01-Nov-2017 Greg Kroah-Hartman <[email protected]>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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Revision tags: v4.14-rc7, v4.14-rc6, v4.14-rc5, v4.14-rc4, v4.14-rc3, v4.14-rc2, v4.14-rc1, v4.13, v4.13-rc7, v4.13-rc6, v4.13-rc5, v4.13-rc4, v4.13-rc3, v4.13-rc2, v4.13-rc1, v4.12, v4.12-rc7, v4.12-rc6, v4.12-rc5, v4.12-rc4, v4.12-rc3, v4.12-rc2, v4.12-rc1, v4.11, v4.11-rc8, v4.11-rc7, v4.11-rc6, v4.11-rc5, v4.11-rc4, v4.11-rc3, v4.11-rc2, v4.11-rc1, v4.10, v4.10-rc8, v4.10-rc7, v4.10-rc6, v4.10-rc5, v4.10-rc4, v4.10-rc3, v4.10-rc2, v4.10-rc1, v4.9, v4.9-rc8, v4.9-rc7, v4.9-rc6, v4.9-rc5, v4.9-rc4, v4.9-rc3, v4.9-rc2, v4.9-rc1, v4.8
# bc8bcf3b 27-Sep-2016 Andreas Gruenbacher <[email protected]>

posix_acl: uapi header split

Export the base definitions and the xattr representation of POSIX ACLs
to user space.

Signed-off-by: Andreas Gruenbacher <[email protected]>
Signed-off-by: Al Viro <v

posix_acl: uapi header split

Export the base definitions and the xattr representation of POSIX ACLs
to user space.

Signed-off-by: Andreas Gruenbacher <[email protected]>
Signed-off-by: Al Viro <[email protected]>

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Revision tags: v4.8-rc8
# 07393101 19-Sep-2016 Jan Kara <[email protected]>

posix_acl: Clear SGID bit when setting file permissions

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in

posix_acl: Clear SGID bit when setting file permissions

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok(). Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2). Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
Signed-off-by: Andreas Gruenbacher <[email protected]>

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Revision tags: v4.8-rc7, v4.8-rc6, v4.8-rc5, v4.8-rc4, v4.8-rc3, v4.8-rc2, v4.8-rc1, v4.7
# 6d4e56ce 11-Jul-2016 Jeff Layton <[email protected]>

posix_acl: de-union a_refcount and a_rcu

Currently the two are unioned together, but I don't think that's safe.

It looks like get_cached_acl could race with the last put in
posix_acl_release. get_c

posix_acl: de-union a_refcount and a_rcu

Currently the two are unioned together, but I don't think that's safe.

It looks like get_cached_acl could race with the last put in
posix_acl_release. get_cached_acl calls atomic_inc_not_zero on
a_refcount, but that field could have already been clobbered by
call_rcu, and may no longer be zero. Fix this by de-unioning the two
fields.

Fixes: b8a7a3a66747 (posix_acl: Inode acl caching fixes)
Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Al Viro <[email protected]>

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Revision tags: v4.7-rc7, v4.7-rc6
# 0d4d717f 27-Jun-2016 Eric W. Biederman <[email protected]>

vfs: Verify acls are valid within superblock's s_user_ns.

Update posix_acl_valid to verify that an acl is within a user namespace.

Update the callers of posix_acl_valid to pass in an appropriate
us

vfs: Verify acls are valid within superblock's s_user_ns.

Update posix_acl_valid to verify that an acl is within a user namespace.

Update the callers of posix_acl_valid to pass in an appropriate
user namespace. For posix_acl_xattr_set and v9fs_xattr_set_acl pass in
inode->i_sb->s_user_ns to posix_acl_valid. For md_unpack_acl pass in
&init_user_ns as no inode or superblock is in sight.

Acked-by: Seth Forshee <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>

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Revision tags: v4.7-rc5, v4.7-rc4, v4.7-rc3, v4.7-rc2, v4.7-rc1, v4.6, v4.6-rc7, v4.6-rc6, v4.6-rc5, v4.6-rc4, v4.6-rc3, v4.6-rc2, v4.6-rc1
# 04c57f45 24-Mar-2016 Andreas Gruenbacher <[email protected]>

posix_acl: Unexport acl_by_type and make it static

acl_by_type(inode, type) returns a pointer to either inode->i_acl or
inode->i_default_acl depending on type. This is useful in
fs/posix_acl.c, but

posix_acl: Unexport acl_by_type and make it static

acl_by_type(inode, type) returns a pointer to either inode->i_acl or
inode->i_default_acl depending on type. This is useful in
fs/posix_acl.c, but should never have been visible outside that file.

Signed-off-by: Andreas Gruenbacher <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Al Viro <[email protected]>

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