[PATCH v16 1/4] Add flags option to get xattr method paired to __vfs_getxattr

From: Mark Salyzyn
Date: Mon Oct 19 2020 - 07:53:21 EST

Add a flag option to get xattr method that could have a bit flag of
XATTR_NOSECURITY passed to it. XATTR_NOSECURITY is generally then
set in the __vfs_getxattr path when called by security
infrastructure.

This handles the case of a union filesystem driver that is being
requested by the security layer to report back the xattr data.

For the use case where access is to be blocked by the security layer.

The path then could be security(dentry) ->
__vfs_getxattr(dentry...XATTR_NOSECURITY) ->
handler->get(dentry...XATTR_NOSECURITY) ->
__vfs_getxattr(lower_dentry...XATTR_NOSECURITY) ->
lower_handler->get(lower_dentry...XATTR_NOSECURITY)
which would report back through the chain data and success as
expected, the logging security layer at the top would have the
data to determine the access permissions and report back the target
context that was blocked.

Without the get handler flag, the path on a union filesystem would be
the errant security(dentry) -> __vfs_getxattr(dentry) ->
handler->get(dentry) -> vfs_getxattr(lower_dentry) -> nested ->
security(lower_dentry, log off) -> lower_handler->get(lower_dentry)
which would report back through the chain no data, and -EACCES.

For selinux for both cases, this would translate to a correctly
determined blocked access. In the first case with this change a correct avc
log would be reported, in the second legacy case an incorrect avc log
would be reported against an uninitialized u:object_r:unlabeled:s0
context making the logs cosmetically useless for audit2allow.

This patch series is inert and is the wide-spread addition of the
flags option for xattr functions, and a replacement of __vfs_getxattr
with __vfs_getxattr(...XATTR_NOSECURITY).

Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Acked-by: Jan Kara <jack@xxxxxxx>
Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
Acked-by: David Sterba <dsterba@xxxxxxxx>
Acked-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Acked-by: Mike Marshall <hubcap@xxxxxxxxxxxx>
Cc: Stephen Smalley <sds@xxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
To: linux-fsdevel@xxxxxxxxxxxxxxx
To: linux-unionfs@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-security-module@xxxxxxxxxxxxxxx
Cc: kernel-team@xxxxxxxxxxx

v16
- rebase

v15
- revert back to v4 as struct xattr_gs_args was not acceptable by the
wider audience. Incorporate any relevant fixes on the way.

v14 (new series):
- Reincorporate back into the bugfix series for overlayfs

v8:
- Documentation reported 'struct xattr_gs_flags' rather than
'struct xattr_gs_flags *args' as argument to get and set methods.

v7:
- missed spots in fs/9p/acl.c, fs/afs/xattr.c, fs/ecryptfs/crypto.c,
fs/ubifs/xattr.c, fs/xfs/libxfs/xfs_attr.c,
security/integrity/evm/evm_main.c and security/smack/smack_lsm.c.

v6:
- kernfs missed a spot

v5:
- introduce struct xattr_gs_args for get and set methods,
__vfs_getxattr and __vfs_setxattr functions.
- cover a missing spot in ext2.
- switch from snprintf to scnprintf for correctness.

v4:
- ifdef __KERNEL__ around XATTR_NOSECURITY to
keep it colocated in uapi headers.

v3:
- poor aim on ubifs not ubifs_xattr_get, but static xattr_get

v2:
- Missed a spot: ubifs, erofs and afs.

v1:
- Removed from an overlayfs patch set, and made independent.
Expect this to be the basis of some security improvements.
---
Documentation/filesystems/locking.rst | 2 +-
fs/9p/acl.c | 3 ++-
fs/9p/xattr.c | 3 ++-
fs/afs/xattr.c | 10 ++++----
fs/btrfs/xattr.c | 3 ++-
fs/ceph/xattr.c | 3 ++-
fs/cifs/xattr.c | 2 +-
fs/ecryptfs/inode.c | 6 +++--
fs/ecryptfs/mmap.c | 2 +-
fs/erofs/xattr.c | 3 ++-
fs/ext2/xattr_security.c | 2 +-
fs/ext2/xattr_trusted.c | 2 +-
fs/ext2/xattr_user.c | 2 +-
fs/ext4/xattr_security.c | 2 +-
fs/ext4/xattr_trusted.c | 2 +-
fs/ext4/xattr_user.c | 2 +-
fs/f2fs/xattr.c | 4 +--
fs/fuse/xattr.c | 4 +--
fs/gfs2/xattr.c | 3 ++-
fs/hfs/attr.c | 2 +-
fs/hfsplus/xattr.c | 3 ++-
fs/hfsplus/xattr_security.c | 3 ++-
fs/hfsplus/xattr_trusted.c | 3 ++-
fs/hfsplus/xattr_user.c | 3 ++-
fs/jffs2/security.c | 3 ++-
fs/jffs2/xattr_trusted.c | 3 ++-
fs/jffs2/xattr_user.c | 3 ++-
fs/jfs/xattr.c | 5 ++--
fs/kernfs/inode.c | 3 ++-
fs/nfs/nfs4proc.c | 9 ++++---
fs/ocfs2/xattr.c | 9 ++++---
fs/orangefs/xattr.c | 3 ++-
fs/overlayfs/super.c | 8 +++---
fs/posix_acl.c | 2 +-
fs/reiserfs/xattr_security.c | 3 ++-
fs/reiserfs/xattr_trusted.c | 3 ++-
fs/reiserfs/xattr_user.c | 3 ++-
fs/squashfs/xattr.c | 2 +-
fs/ubifs/xattr.c | 3 ++-
fs/xattr.c | 36 +++++++++++++--------------
fs/xfs/xfs_xattr.c | 3 ++-
include/linux/xattr.h | 9 ++++---
include/uapi/linux/xattr.h | 7 ++++--
mm/shmem.c | 3 ++-
net/socket.c | 3 ++-
security/commoncap.c | 6 +++--
security/integrity/evm/evm_main.c | 3 ++-
security/selinux/hooks.c | 11 +++++---
security/smack/smack_lsm.c | 5 ++--
49 files changed, 133 insertions(+), 89 deletions(-)

diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index c0f2c7586531..bcb092e74c1e 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -125,7 +125,7 @@ prototypes::
bool (*list)(struct dentry *dentry);
int (*get)(const struct xattr_handler *handler, struct dentry *dentry,
struct inode *inode, const char *name, void *buffer,
- size_t size);
+ size_t size, int flags);
int (*set)(const struct xattr_handler *handler, struct dentry *dentry,
struct inode *inode, const char *name, const void *buffer,
size_t size, int flags);
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index 6261719f6f2a..cb14e8b312bc 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -214,7 +214,8 @@ int v9fs_acl_mode(struct inode *dir, umode_t *modep,

static int v9fs_xattr_get_acl(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
struct v9fs_session_info *v9ses;
struct posix_acl *acl;
diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
index ac8ff8ca4c11..5cfa772452fd 100644
--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -139,7 +139,8 @@ ssize_t v9fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)

static int v9fs_xattr_handler_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
const char *full_name = xattr_full_name(handler, name);

diff --git a/fs/afs/xattr.c b/fs/afs/xattr.c
index 84f3c4f57531..00cf18cff98f 100644
--- a/fs/afs/xattr.c
+++ b/fs/afs/xattr.c
@@ -59,7 +59,7 @@ static const struct afs_operation_ops afs_fetch_acl_operation = {
static int afs_xattr_get_acl(const struct xattr_handler *handler,
struct dentry *dentry,
struct inode *inode, const char *name,
- void *buffer, size_t size)
+ void *buffer, size_t size, int flags)
{
struct afs_operation *op;
struct afs_vnode *vnode = AFS_FS_I(inode);
@@ -165,7 +165,7 @@ static const struct afs_operation_ops yfs_fetch_opaque_acl_operation = {
static int afs_xattr_get_yfs(const struct xattr_handler *handler,
struct dentry *dentry,
struct inode *inode, const char *name,
- void *buffer, size_t size)
+ void *buffer, size_t size, int flags)
{
struct afs_operation *op;
struct afs_vnode *vnode = AFS_FS_I(inode);
@@ -288,7 +288,7 @@ static const struct xattr_handler afs_xattr_yfs_handler = {
static int afs_xattr_get_cell(const struct xattr_handler *handler,
struct dentry *dentry,
struct inode *inode, const char *name,
- void *buffer, size_t size)
+ void *buffer, size_t size, int flags)
{
struct afs_vnode *vnode = AFS_FS_I(inode);
struct afs_cell *cell = vnode->volume->cell;
@@ -315,7 +315,7 @@ static const struct xattr_handler afs_xattr_afs_cell_handler = {
static int afs_xattr_get_fid(const struct xattr_handler *handler,
struct dentry *dentry,
struct inode *inode, const char *name,
- void *buffer, size_t size)
+ void *buffer, size_t size, int flags)
{
struct afs_vnode *vnode = AFS_FS_I(inode);
char text[16 + 1 + 24 + 1 + 8 + 1];
@@ -353,7 +353,7 @@ static const struct xattr_handler afs_xattr_afs_fid_handler = {
static int afs_xattr_get_volume(const struct xattr_handler *handler,
struct dentry *dentry,
struct inode *inode, const char *name,
- void *buffer, size_t size)
+ void *buffer, size_t size, int flags)
{
struct afs_vnode *vnode = AFS_FS_I(inode);
const char *volname = vnode->volume->name;
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 95d9aebff2c4..1e522e145344 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -353,7 +353,8 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)

static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
name = xattr_full_name(handler, name);
return btrfs_getxattr(inode, name, buffer, size);
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 3a733ac33d9b..ffc370538781 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1154,7 +1154,8 @@ int __ceph_setxattr(struct inode *inode, const char *name,

static int ceph_get_xattr_handler(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size,
+ int flags)
{
if (!ceph_is_valid_xattr(name))
return -EOPNOTSUPP;
diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index b8299173ea7e..032df60c4afa 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -281,7 +281,7 @@ static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,

static int cifs_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size, int flags)
{
ssize_t rc = -EOPNOTSUPP;
unsigned int xid;
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index e23752d9a79f..12616d5510cf 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -1040,7 +1040,8 @@ ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
goto out;
}
inode_lock(lower_inode);
- rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
+ rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size,
+ XATTR_NOSECURITY);
inode_unlock(lower_inode);
out:
return rc;
@@ -1125,7 +1126,8 @@ const struct inode_operations ecryptfs_main_iops = {

static int ecryptfs_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return ecryptfs_getxattr(dentry, inode, name, buffer, size);
}
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 019572c6b39a..bc1ca4dea751 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -422,7 +422,7 @@ static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode)
}
inode_lock(lower_inode);
size = __vfs_getxattr(lower_dentry, lower_inode, ECRYPTFS_XATTR_NAME,
- xattr_virt, PAGE_SIZE);
+ xattr_virt, PAGE_SIZE, XATTR_NOSECURITY);
if (size < 0)
size = 8;
put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt);
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
index 5bde77d70852..58cf0cf1b818 100644
--- a/fs/erofs/xattr.c
+++ b/fs/erofs/xattr.c
@@ -463,7 +463,8 @@ int erofs_getxattr(struct inode *inode, int index,

static int erofs_xattr_generic_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);

diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
index 9a682e440acb..d5f6eb0b487b 100644
--- a/fs/ext2/xattr_security.c
+++ b/fs/ext2/xattr_security.c
@@ -11,7 +11,7 @@
static int
ext2_xattr_security_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
return ext2_xattr_get(inode, EXT2_XATTR_INDEX_SECURITY, name,
buffer, size);
diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c
index 49add1107850..8d313664f0fa 100644
--- a/fs/ext2/xattr_trusted.c
+++ b/fs/ext2/xattr_trusted.c
@@ -18,7 +18,7 @@ ext2_xattr_trusted_list(struct dentry *dentry)
static int
ext2_xattr_trusted_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
return ext2_xattr_get(inode, EXT2_XATTR_INDEX_TRUSTED, name,
buffer, size);
diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
index c243a3b4d69d..712b7c95cc64 100644
--- a/fs/ext2/xattr_user.c
+++ b/fs/ext2/xattr_user.c
@@ -20,7 +20,7 @@ ext2_xattr_user_list(struct dentry *dentry)
static int
ext2_xattr_user_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
if (!test_opt(inode->i_sb, XATTR_USER))
return -EOPNOTSUPP;
diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
index 197a9d8a15ef..50fb71393fb6 100644
--- a/fs/ext4/xattr_security.c
+++ b/fs/ext4/xattr_security.c
@@ -15,7 +15,7 @@
static int
ext4_xattr_security_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY,
name, buffer, size);
diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
index e9389e5d75c3..64bd8f86c1f1 100644
--- a/fs/ext4/xattr_trusted.c
+++ b/fs/ext4/xattr_trusted.c
@@ -22,7 +22,7 @@ ext4_xattr_trusted_list(struct dentry *dentry)
static int
ext4_xattr_trusted_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED,
name, buffer, size);
diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
index d4546184b34b..b7301373820e 100644
--- a/fs/ext4/xattr_user.c
+++ b/fs/ext4/xattr_user.c
@@ -21,7 +21,7 @@ ext4_xattr_user_list(struct dentry *dentry)
static int
ext4_xattr_user_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
if (!test_opt(inode->i_sb, XATTR_USER))
return -EOPNOTSUPP;
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index 65afcc3cc68a..eb892dbe85e3 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -44,7 +44,7 @@ static void xattr_free(struct f2fs_sb_info *sbi, void *xattr_addr,

static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

@@ -99,7 +99,7 @@ static bool f2fs_xattr_trusted_list(struct dentry *dentry)

static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
if (buffer)
*((char *)buffer) = F2FS_I(inode)->i_advise;
diff --git a/fs/fuse/xattr.c b/fs/fuse/xattr.c
index 20d052e08b3b..414718a51c25 100644
--- a/fs/fuse/xattr.c
+++ b/fs/fuse/xattr.c
@@ -176,7 +176,7 @@ int fuse_removexattr(struct inode *inode, const char *name)

static int fuse_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size, int flags)
{
return fuse_getxattr(inode, name, value, size);
}
@@ -199,7 +199,7 @@ static bool no_xattr_list(struct dentry *dentry)

static int no_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size, int flags)
{
return -EOPNOTSUPP;
}
diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
index 9d7667bc4292..2e4a9b9dcad1 100644
--- a/fs/gfs2/xattr.c
+++ b/fs/gfs2/xattr.c
@@ -588,7 +588,8 @@ static int __gfs2_xattr_get(struct inode *inode, const char *name,

static int gfs2_xattr_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
diff --git a/fs/hfs/attr.c b/fs/hfs/attr.c
index 74fa62643136..08222a9c5d31 100644
--- a/fs/hfs/attr.c
+++ b/fs/hfs/attr.c
@@ -115,7 +115,7 @@ static ssize_t __hfs_getxattr(struct inode *inode, enum hfs_xattr_type type,

static int hfs_xattr_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size, int flags)
{
return __hfs_getxattr(inode, handler->flags, value, size);
}
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index bb0b27d88e50..381c2aaedbc8 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -839,7 +839,8 @@ static int hfsplus_removexattr(struct inode *inode, const char *name)

static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
/*
* Don't allow retrieving properly prefixed attributes
diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
index cfbe6a3bfb1e..43e28b3a716d 100644
--- a/fs/hfsplus/xattr_security.c
+++ b/fs/hfsplus/xattr_security.c
@@ -15,7 +15,8 @@

static int hfsplus_security_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer,
+ size_t size, int flags)
{
return hfsplus_getxattr(inode, name, buffer, size,
XATTR_SECURITY_PREFIX,
diff --git a/fs/hfsplus/xattr_trusted.c b/fs/hfsplus/xattr_trusted.c
index fbad91e1dada..54d926314f8c 100644
--- a/fs/hfsplus/xattr_trusted.c
+++ b/fs/hfsplus/xattr_trusted.c
@@ -14,7 +14,8 @@

static int hfsplus_trusted_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer,
+ size_t size, int flags)
{
return hfsplus_getxattr(inode, name, buffer, size,
XATTR_TRUSTED_PREFIX,
diff --git a/fs/hfsplus/xattr_user.c b/fs/hfsplus/xattr_user.c
index 74d19faf255e..4d2b1ffff887 100644
--- a/fs/hfsplus/xattr_user.c
+++ b/fs/hfsplus/xattr_user.c
@@ -14,7 +14,8 @@

static int hfsplus_user_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{

return hfsplus_getxattr(inode, name, buffer, size,
diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
index c2332e30f218..e6f42fe435af 100644
--- a/fs/jffs2/security.c
+++ b/fs/jffs2/security.c
@@ -50,7 +50,8 @@ int jffs2_init_security(struct inode *inode, struct inode *dir,
/* ---- XATTR Handler for "security.*" ----------------- */
static int jffs2_security_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return do_jffs2_getxattr(inode, JFFS2_XPREFIX_SECURITY,
name, buffer, size);
diff --git a/fs/jffs2/xattr_trusted.c b/fs/jffs2/xattr_trusted.c
index 5d6030826c52..9dccaae549f5 100644
--- a/fs/jffs2/xattr_trusted.c
+++ b/fs/jffs2/xattr_trusted.c
@@ -18,7 +18,8 @@

static int jffs2_trusted_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return do_jffs2_getxattr(inode, JFFS2_XPREFIX_TRUSTED,
name, buffer, size);
diff --git a/fs/jffs2/xattr_user.c b/fs/jffs2/xattr_user.c
index 9d027b4abcf9..c0983a3e810b 100644
--- a/fs/jffs2/xattr_user.c
+++ b/fs/jffs2/xattr_user.c
@@ -18,7 +18,8 @@

static int jffs2_user_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return do_jffs2_getxattr(inode, JFFS2_XPREFIX_USER,
name, buffer, size);
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index db41e7803163..5c79a35bf62f 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -925,7 +925,7 @@ static int __jfs_xattr_set(struct inode *inode, const char *name,

static int jfs_xattr_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size, int flags)
{
name = xattr_full_name(handler, name);
return __jfs_getxattr(inode, name, value, size);
@@ -942,7 +942,8 @@ static int jfs_xattr_set(const struct xattr_handler *handler,

static int jfs_xattr_get_os2(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size,
+ int flags)
{
if (is_known_namespace(name))
return -EOPNOTSUPP;
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index fc2469a20fed..1c9e4eca3a4e 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -310,7 +310,8 @@ int kernfs_xattr_set(struct kernfs_node *kn, const char *name,

static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *suffix, void *value, size_t size)
+ const char *suffix, void *value, size_t size,
+ int flags)
{
const char *name = xattr_full_name(handler, suffix);
struct kernfs_node *kn = inode->i_private;
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 6e95c85fe395..33efea1da3bb 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7401,7 +7401,8 @@ static int nfs4_xattr_set_nfs4_acl(const struct xattr_handler *handler,

static int nfs4_xattr_get_nfs4_acl(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *key, void *buf, size_t buflen)
+ const char *key, void *buf, size_t buflen,
+ int flags)
{
return nfs4_proc_get_acl(inode, buf, buflen);
}
@@ -7426,7 +7427,8 @@ static int nfs4_xattr_set_nfs4_label(const struct xattr_handler *handler,

static int nfs4_xattr_get_nfs4_label(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *key, void *buf, size_t buflen)
+ const char *key, void *buf, size_t buflen,
+ int flags)
{
if (security_ismaclabel(key))
return nfs4_get_security_label(inode, buf, buflen);
@@ -7503,7 +7505,8 @@ static int nfs4_xattr_set_nfs4_user(const struct xattr_handler *handler,

static int nfs4_xattr_get_nfs4_user(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *key, void *buf, size_t buflen)
+ const char *key, void *buf, size_t buflen,
+ int flags)
{
struct nfs_access_entry cache;
ssize_t ret;
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 9ccd19d8f7b1..0ed0a61d4c5f 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -7242,7 +7242,8 @@ int ocfs2_init_security_and_acl(struct inode *dir,
*/
static int ocfs2_xattr_security_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_SECURITY,
name, buffer, size);
@@ -7314,7 +7315,8 @@ const struct xattr_handler ocfs2_xattr_security_handler = {
*/
static int ocfs2_xattr_trusted_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return ocfs2_xattr_get(inode, OCFS2_XATTR_INDEX_TRUSTED,
name, buffer, size);
@@ -7340,7 +7342,8 @@ const struct xattr_handler ocfs2_xattr_trusted_handler = {
*/
static int ocfs2_xattr_user_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

diff --git a/fs/orangefs/xattr.c b/fs/orangefs/xattr.c
index bdc285aea360..ef4180bff7bb 100644
--- a/fs/orangefs/xattr.c
+++ b/fs/orangefs/xattr.c
@@ -541,7 +541,8 @@ static int orangefs_xattr_get_default(const struct xattr_handler *handler,
struct inode *inode,
const char *name,
void *buffer,
- size_t size)
+ size_t size,
+ int flags)
{
return orangefs_inode_getxattr(inode, name, buffer, size);

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 290983bcfbb3..f41353ba1e68 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -928,7 +928,7 @@ static unsigned int ovl_split_lowerdirs(char *str)
static int __maybe_unused
ovl_posix_acl_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size, int flags)
{
return ovl_xattr_get(dentry, inode, handler->name, buffer, size);
}
@@ -993,7 +993,8 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler,

static int ovl_own_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return -EOPNOTSUPP;
}
@@ -1008,7 +1009,8 @@ static int ovl_own_xattr_set(const struct xattr_handler *handler,

static int ovl_other_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
return ovl_xattr_get(dentry, inode, name, buffer, size);
}
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 95882b3f5f62..f3fbc26df68a 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -835,7 +835,7 @@ EXPORT_SYMBOL (posix_acl_to_xattr);
static int
posix_acl_xattr_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *value, size_t size)
+ const char *name, void *value, size_t size, int flags)
{
struct posix_acl *acl;
int error;
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
index 20be9a0e5870..eedfa07a4fd0 100644
--- a/fs/reiserfs/xattr_security.c
+++ b/fs/reiserfs/xattr_security.c
@@ -11,7 +11,8 @@

static int
security_get(const struct xattr_handler *handler, struct dentry *unused,
- struct inode *inode, const char *name, void *buffer, size_t size)
+ struct inode *inode, const char *name, void *buffer, size_t size,
+ int flags)
{
if (IS_PRIVATE(inode))
return -EPERM;
diff --git a/fs/reiserfs/xattr_trusted.c b/fs/reiserfs/xattr_trusted.c
index 5ed48da3d02b..2d11d98605dd 100644
--- a/fs/reiserfs/xattr_trusted.c
+++ b/fs/reiserfs/xattr_trusted.c
@@ -10,7 +10,8 @@

static int
trusted_get(const struct xattr_handler *handler, struct dentry *unused,
- struct inode *inode, const char *name, void *buffer, size_t size)
+ struct inode *inode, const char *name, void *buffer, size_t size,
+ int flags)
{
if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(inode))
return -EPERM;
diff --git a/fs/reiserfs/xattr_user.c b/fs/reiserfs/xattr_user.c
index a573ca45bacc..2a59d85c69c9 100644
--- a/fs/reiserfs/xattr_user.c
+++ b/fs/reiserfs/xattr_user.c
@@ -9,7 +9,8 @@

static int
user_get(const struct xattr_handler *handler, struct dentry *unused,
- struct inode *inode, const char *name, void *buffer, size_t size)
+ struct inode *inode, const char *name, void *buffer, size_t size,
+ int flags)
{
if (!reiserfs_xattrs_user(inode->i_sb))
return -EOPNOTSUPP;
diff --git a/fs/squashfs/xattr.c b/fs/squashfs/xattr.c
index e1e3f3dd5a06..d8d58c990652 100644
--- a/fs/squashfs/xattr.c
+++ b/fs/squashfs/xattr.c
@@ -204,7 +204,7 @@ static int squashfs_xattr_handler_get(const struct xattr_handler *handler,
struct dentry *unused,
struct inode *inode,
const char *name,
- void *buffer, size_t size)
+ void *buffer, size_t size, int flags)
{
return squashfs_xattr_get(inode, handler->flags, name,
buffer, size);
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index a0b9b349efe6..1afb62827a63 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -671,7 +671,8 @@ int ubifs_init_security(struct inode *dentry, struct inode *inode,

static int xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
inode->i_ino, dentry, size);
diff --git a/fs/xattr.c b/fs/xattr.c
index cd7a563e8bcd..d6bf5a7e2420 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -345,7 +345,7 @@ vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value,
return PTR_ERR(handler);
if (!handler->get)
return -EOPNOTSUPP;
- error = handler->get(handler, dentry, inode, name, NULL, 0);
+ error = handler->get(handler, dentry, inode, name, NULL, 0, 0);
if (error < 0)
return error;

@@ -356,32 +356,20 @@ vfs_getxattr_alloc(struct dentry *dentry, const char *name, char **xattr_value,
memset(value, 0, error + 1);
}

- error = handler->get(handler, dentry, inode, name, value, error);
+ error = handler->get(handler, dentry, inode, name, value, error, 0);
*xattr_value = value;
return error;
}

ssize_t
__vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
- void *value, size_t size)
+ void *value, size_t size, int flags)
{
const struct xattr_handler *handler;
-
- handler = xattr_resolve_name(inode, &name);
- if (IS_ERR(handler))
- return PTR_ERR(handler);
- if (!handler->get)
- return -EOPNOTSUPP;
- return handler->get(handler, dentry, inode, name, value, size);
-}
-EXPORT_SYMBOL(__vfs_getxattr);
-
-ssize_t
-vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
-{
- struct inode *inode = dentry->d_inode;
int error;

+ if (flags & XATTR_NOSECURITY)
+ goto nolsm;
error = xattr_permission(inode, name, MAY_READ);
if (error)
return error;
@@ -403,7 +391,19 @@ vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
return ret;
}
nolsm:
- return __vfs_getxattr(dentry, inode, name, value, size);
+ handler = xattr_resolve_name(inode, &name);
+ if (IS_ERR(handler))
+ return PTR_ERR(handler);
+ if (!handler->get)
+ return -EOPNOTSUPP;
+ return handler->get(handler, dentry, inode, name, value, size, flags);
+}
+EXPORT_SYMBOL(__vfs_getxattr);
+
+ssize_t
+vfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size)
+{
+ return __vfs_getxattr(dentry, dentry->d_inode, name, value, size, 0);
}
EXPORT_SYMBOL_GPL(vfs_getxattr);

diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index bca48b308c02..dd81d10d0679 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -19,7 +19,8 @@

static int
xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused,
- struct inode *inode, const char *name, void *value, size_t size)
+ struct inode *inode, const char *name, void *value, size_t size,
+ int flags)
{
struct xfs_da_args args = {
.dp = XFS_I(inode),
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 10b4dc2709f0..28c0da780302 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -31,10 +31,10 @@ struct xattr_handler {
const char *prefix;
int flags; /* fs private flags */
bool (*list)(struct dentry *dentry);
- int (*get)(const struct xattr_handler *, struct dentry *dentry,
+ int (*get)(const struct xattr_handler *handler, struct dentry *dentry,
struct inode *inode, const char *name, void *buffer,
- size_t size);
- int (*set)(const struct xattr_handler *, struct dentry *dentry,
+ size_t size, int flags);
+ int (*set)(const struct xattr_handler *handler, struct dentry *dentry,
struct inode *inode, const char *name, const void *buffer,
size_t size, int flags);
};
@@ -47,7 +47,8 @@ struct xattr {
size_t value_len;
};

-ssize_t __vfs_getxattr(struct dentry *, struct inode *, const char *, void *, size_t);
+ssize_t __vfs_getxattr(struct dentry *dentry, struct inode *inode,
+ const char *name, void *buffer, size_t size, int flags);
ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int);
diff --git a/include/uapi/linux/xattr.h b/include/uapi/linux/xattr.h
index 9463db2dfa9d..d22191a3cf09 100644
--- a/include/uapi/linux/xattr.h
+++ b/include/uapi/linux/xattr.h
@@ -18,8 +18,11 @@
#if __UAPI_DEF_XATTR
#define __USE_KERNEL_XATTR_DEFS

-#define XATTR_CREATE 0x1 /* set value, fail if attr already exists */
-#define XATTR_REPLACE 0x2 /* set value, fail if attr does not exist */
+#define XATTR_CREATE 0x1 /* set value, fail if attr already exists */
+#define XATTR_REPLACE 0x2 /* set value, fail if attr does not exist */
+#ifdef __KERNEL__ /* following is kernel internal, colocated for maintenance */
+#define XATTR_NOSECURITY 0x4 /* get value, do not involve security check */
+#endif
#endif

/* Namespaces */
diff --git a/mm/shmem.c b/mm/shmem.c
index 537c137698f8..2a2770714b27 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3269,7 +3269,8 @@ static int shmem_initxattrs(struct inode *inode,

static int shmem_xattr_handler_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
- const char *name, void *buffer, size_t size)
+ const char *name, void *buffer, size_t size,
+ int flags)
{
struct shmem_inode_info *info = SHMEM_I(inode);

diff --git a/net/socket.c b/net/socket.c
index 6e6cccc2104f..926f249c76d0 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -314,7 +314,8 @@ static const struct dentry_operations sockfs_dentry_operations = {

static int sockfs_xattr_get(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
- const char *suffix, void *value, size_t size)
+ const char *suffix, void *value, size_t size,
+ int flags)
{
if (value) {
if (dentry->d_name.len + 1 > size)
diff --git a/security/commoncap.c b/security/commoncap.c
index 59bf3c1674c8..61520851581a 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -297,7 +297,8 @@ int cap_inode_need_killpriv(struct dentry *dentry)
struct inode *inode = d_backing_inode(dentry);
int error;

- error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0);
+ error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0,
+ XATTR_NOSECURITY);
return error > 0;
}

@@ -586,7 +587,8 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data

fs_ns = inode->i_sb->s_user_ns;
size = __vfs_getxattr((struct dentry *)dentry, inode,
- XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ);
+ XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ,
+ XATTR_NOSECURITY);
if (size == -ENODATA || size == -EOPNOTSUPP)
/* no data, that's ok */
return -ENODATA;
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 76d19146d74b..d3b358bc1e5e 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -101,7 +101,8 @@ static int evm_find_protected_xattrs(struct dentry *dentry)
return -EOPNOTSUPP;

list_for_each_entry_lockless(xattr, &evm_config_xattrnames, list) {
- error = __vfs_getxattr(dentry, inode, xattr->name, NULL, 0);
+ error = __vfs_getxattr(dentry, inode, xattr->name, NULL, 0,
+ XATTR_NOSECURITY);
if (error < 0) {
if (error == -ENODATA)
continue;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 6b1826fc3658..349685f1f130 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -504,7 +504,8 @@ static int sb_finish_set_opts(struct super_block *sb)
goto out;
}

- rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
+ rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL,
+ 0, XATTR_NOSECURITY);
if (rc < 0 && rc != -ENODATA) {
if (rc == -EOPNOTSUPP)
pr_warn("SELinux: (dev %s, type "
@@ -1332,12 +1333,14 @@ static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
return -ENOMEM;

context[len] = '\0';
- rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
+ rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len,
+ XATTR_NOSECURITY);
if (rc == -ERANGE) {
kfree(context);

/* Need a larger buffer. Query for the right size. */
- rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
+ rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0,
+ XATTR_NOSECURITY);
if (rc < 0)
return rc;

@@ -1348,7 +1351,7 @@ static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,

context[len] = '\0';
rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
- context, len);
+ context, len, XATTR_NOSECURITY);
}
if (rc < 0) {
kfree(context);
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5c90b9fa4d40..fe8d33b287f5 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -289,7 +289,8 @@ static struct smack_known *smk_fetch(const char *name, struct inode *ip,
if (buffer == NULL)
return ERR_PTR(-ENOMEM);

- rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
+ rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL,
+ XATTR_NOSECURITY);
if (rc < 0)
skp = ERR_PTR(rc);
else if (rc == 0)
@@ -3432,7 +3433,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
} else {
rc = __vfs_getxattr(dp, inode,
XATTR_NAME_SMACKTRANSMUTE, trattr,
- TRANS_TRUE_SIZE);
+ TRANS_TRUE_SIZE, XATTR_NOSECURITY);
if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
TRANS_TRUE_SIZE) != 0)
rc = -EINVAL;
--
2.29.0.rc1.297.gfa9743e501-goog