10 Oct, 2018
1 commit
-
commit ffc4c92227db5699493e43eb140b4cb5904c30ff upstream.
Commit 786534b92f3c introduced a regression that caused listxattr to
return the POSIX ACL attribute names even though sysfs doesn't support
POSIX ACLs. This happens because simple_xattr_list checks for NULL
i_acl / i_default_acl, but inode_init_always initializes those fields
to ACL_NOT_CACHED ((void *)-1). For example:
$ getfattr -m- -d /sys
/sys: system.posix_acl_access: Operation not supported
/sys: system.posix_acl_default: Operation not supported
Fix this in simple_xattr_list by checking if the filesystem supports POSIX ACLs.Fixes: 786534b92f3c ("tmpfs: listxattr should include POSIX ACL xattrs")
Reported-by: Marc Aurèle La France
Tested-by: Marc Aurèle La France
Signed-off-by: Andreas Gruenbacher
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Al Viro
Signed-off-by: Greg Kroah-Hartman
10 Sep, 2018
1 commit
-
commit 82c9a927bc5df6e06b72d206d24a9d10cced4eb5 upstream.
When running in a container with a user namespace, if you call getxattr
with name = "system.posix_acl_access" and size % 8 != 4, then getxattr
silently skips the user namespace fixup that it normally does resulting in
un-fixed-up data being returned.
This is caused by posix_acl_fix_xattr_to_user() being passed the total
buffer size and not the actual size of the xattr as returned by
vfs_getxattr().
This commit passes the actual length of the xattr as returned by
vfs_getxattr() down.A reproducer for the issue is:
touch acl_posix
setfacl -m user:0:rwx acl_posix
and the compile:
#define _GNU_SOURCE
#include
#include
#include
#include
#include
#include
#include/* Run in user namespace with nsuid 0 mapped to uid != 0 on the host. */
int main(int argc, void **argv)
{
ssize_t ret1, ret2;
char buf1[128], buf2[132];
int fret = EXIT_SUCCESS;
char *file;if (argc < 2) {
fprintf(stderr,
"Please specify a file with "
"\"system.posix_acl_access\" permissions set\n");
_exit(EXIT_FAILURE);
}
file = argv[1];ret1 = getxattr(file, "system.posix_acl_access",
buf1, sizeof(buf1));
if (ret1 < 0) {
fprintf(stderr, "%s - Failed to retrieve "
"\"system.posix_acl_access\" "
"from \"%s\"\n", strerror(errno), file);
_exit(EXIT_FAILURE);
}ret2 = getxattr(file, "system.posix_acl_access",
buf2, sizeof(buf2));
if (ret2 < 0) {
fprintf(stderr, "%s - Failed to retrieve "
"\"system.posix_acl_access\" "
"from \"%s\"\n", strerror(errno), file);
_exit(EXIT_FAILURE);
}if (ret1 != ret2) {
fprintf(stderr, "The value of \"system.posix_acl_"
"access\" for file \"%s\" changed "
"between two successive calls\n", file);
_exit(EXIT_FAILURE);
}for (ssize_t i = 0; i < ret2; i++) {
if (buf1[i] == buf2[i])
continue;fprintf(stderr,
"Unexpected different in byte %zd: "
"%02x != %02x\n", i, buf1[i], buf2[i]);
fret = EXIT_FAILURE;
}if (fret == EXIT_SUCCESS)
fprintf(stderr, "Test passed\n");
else
fprintf(stderr, "Test failed\n");_exit(fret);
}
and run:./tester acl_posix
On a non-fixed up kernel this should return something like:
root@c1:/# ./t
Unexpected different in byte 16: ffffffa0 != 00
Unexpected different in byte 17: ffffff86 != 00
Unexpected different in byte 18: 01 != 00and on a fixed kernel:
root@c1:~# ./t
Test passedCc: stable@vger.kernel.org
Fixes: 2f6f0654ab61 ("userns: Convert vfs posix_acl support to use kuids and kgids")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=199945
Reported-by: Colin Watson
Signed-off-by: Christian Brauner
Acked-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
Signed-off-by: Greg Kroah-Hartman
04 Oct, 2017
1 commit
-
security_inode_getsecurity() provides the text string value
of a security attribute. It does not provide a "secctx".
The code in xattr_getsecurity() that calls security_inode_getsecurity()
and then calls security_release_secctx() happened to work because
SElinux and Smack treat the attribute and the secctx the same way.
It fails for cap_inode_getsecurity(), because that module has no
secctx that ever needs releasing. It turns out that Smack is the
one that's doing things wrong by not allocating memory when instructed
to do so by the "alloc" parameter.The fix is simple enough. Change the security_release_secctx() to
kfree() because it isn't a secctx being returned by
security_inode_getsecurity(). Change Smack to allocate the string when
told to do so.Note: this also fixes memory leaks for LSMs which implement
inode_getsecurity but not release_secctx, such as capabilities.Signed-off-by: Casey Schaufler
Reported-by: Konstantin Khlebnikov
Cc: stable@vger.kernel.org
Signed-off-by: James Morris
14 Sep, 2017
1 commit
-
Pull overlayfs updates from Miklos Szeredi:
"This fixes d_ino correctness in readdir, which brings overlayfs on par
with normal filesystems regarding inode number semantics, as long as
all layers are on the same filesystem.There are also some bug fixes, one in particular (random ioctl's
shouldn't be able to modify lower layers) that touches some vfs code,
but of course no-op for non-overlay fs"* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: fix false positive ESTALE on lookup
ovl: don't allow writing ioctl on lower layer
ovl: fix relatime for directories
vfs: add flags to d_real()
ovl: cleanup d_real for negative
ovl: constant d_ino for non-merge dirs
ovl: constant d_ino across copy up
ovl: fix readdir error value
ovl: check snprintf return
05 Sep, 2017
1 commit
-
Problem with ioctl() is that it's a file operation, yet often used as an
inode operation (i.e. modify the inode despite the file being opened for
read-only).mnt_want_write_file() is used by filesystems in such cases to get write
access on an arbitrary open file.Since overlayfs lets filesystems do all file operations, including ioctl,
this can lead to mnt_want_write_file() returning OK for a lower file and
modification of that lower file.This patch prevents modification by checking if the file is from an
overlayfs lower layer and returning EPERM in that case.Need to introduce a mnt_want_write_file_path() variant that still does the
old thing for inode operations that can do the copy up + modification
correctly in such cases (fchown, fsetxattr, fremovexattr).This does not address the correctness of such ioctls on overlayfs (the
correct way would be to copy up and attempt to perform ioctl on upper
file).In theory this could be a regression. We very much hope that nobody is
relying on such a hack in any sane setup.While this patch meddles in VFS code, it has no effect on non-overlayfs
filesystems.Reported-by: "zhangyi (F)"
Signed-off-by: Miklos Szeredi
02 Sep, 2017
1 commit
-
Root in a non-initial user ns cannot be trusted to write a traditional
security.capability xattr. If it were allowed to do so, then any
unprivileged user on the host could map his own uid to root in a private
namespace, write the xattr, and execute the file with privilege on the
host.However supporting file capabilities in a user namespace is very
desirable. Not doing so means that any programs designed to run with
limited privilege must continue to support other methods of gaining and
dropping privilege. For instance a program installer must detect
whether file capabilities can be assigned, and assign them if so but set
setuid-root otherwise. The program in turn must know how to drop
partial capabilities, and do so only if setuid-root.This patch introduces v3 of the security.capability xattr. It builds a
vfs_ns_cap_data struct by appending a uid_t rootid to struct
vfs_cap_data. This is the absolute uid_t (that is, the uid_t in user
namespace which mounted the filesystem, usually init_user_ns) of the
root id in whose namespaces the file capabilities may take effect.When a task asks to write a v2 security.capability xattr, if it is
privileged with respect to the userns which mounted the filesystem, then
nothing should change. Otherwise, the kernel will transparently rewrite
the xattr as a v3 with the appropriate rootid. This is done during the
execution of setxattr() to catch user-space-initiated capability writes.
Subsequently, any task executing the file which has the noted kuid as
its root uid, or which is in a descendent user_ns of such a user_ns,
will run the file with capabilities.Similarly when asking to read file capabilities, a v3 capability will
be presented as v2 if it applies to the caller's namespace.If a task writes a v3 security.capability, then it can provide a uid for
the xattr so long as the uid is valid in its own user namespace, and it
is privileged with CAP_SETFCAP over its namespace. The kernel will
translate that rootid to an absolute uid, and write that to disk. After
this, a task in the writer's namespace will not be able to use those
capabilities (unless rootid was 0), but a task in a namespace where the
given uid is root will.Only a single security.capability xattr may exist at a time for a given
file. A task may overwrite an existing xattr so long as it is
privileged over the inode. Note this is a departure from previous
semantics, which required privilege to remove a security.capability
xattr. This check can be re-added if deemed useful.This allows a simple setxattr to work, allows tar/untar to work, and
allows us to tar in one namespace and untar in another while preserving
the capability, without risking leaking privilege into a parent
namespace.Example using tar:
$ cp /bin/sleep sleepx
$ mkdir b1 b2
$ lxc-usernsexec -m b:0:100000:1 -m b:1:$(id -u):1 -- chown 0:0 b1
$ lxc-usernsexec -m b:0:100001:1 -m b:1:$(id -u):1 -- chown 0:0 b2
$ lxc-usernsexec -m b:0:100000:1000 -- tar --xattrs-include=security.capability --xattrs -cf b1/sleepx.tar sleepx
$ lxc-usernsexec -m b:0:100001:1000 -- tar --xattrs-include=security.capability --xattrs -C b2 -xf b1/sleepx.tar
$ lxc-usernsexec -m b:0:100001:1000 -- getcap b2/sleepx
b2/sleepx = cap_sys_admin+ep
# /opt/ltp/testcases/bin/getv3xattr b2/sleepx
v3 xattr, rootid is 100001A patch to linux-test-project adding a new set of tests for this
functionality is in the nsfscaps branch at github.com/hallyn/ltpChangelog:
Nov 02 2016: fix invalid check at refuse_fcap_overwrite()
Nov 07 2016: convert rootid from and to fs user_ns
(From ebiederm: mar 28 2017)
commoncap.c: fix typos - s/v4/v3
get_vfs_caps_from_disk: clarify the fs_ns root access check
nsfscaps: change the code split for cap_inode_setxattr()
Apr 09 2017:
don't return v3 cap for caps owned by current root.
return a v2 cap for a true v2 cap in non-init ns
Apr 18 2017:
. Change the flow of fscap writing to support s_user_ns writing.
. Remove refuse_fcap_overwrite(). The value of the previous
xattr doesn't matter.
Apr 24 2017:
. incorporate Eric's incremental diff
. move cap_convert_nscap to setxattr and simplify its usage
May 8, 2017:
. fix leaking dentry refcount in cap_inode_getsecuritySigned-off-by: Serge Hallyn
Signed-off-by: Eric W. Biederman
09 May, 2017
2 commits
-
There are many code paths opencoding kvmalloc. Let's use the helper
instead. The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator. E.g.
allocation requests
Reviewed-by: Boris Ostrovsky # Xen bits
Acked-by: Kees Cook
Acked-by: Vlastimil Babka
Acked-by: Andreas Dilger # Lustre
Acked-by: Christian Borntraeger # KVM/s390
Acked-by: Dan Williams # nvdim
Acked-by: David Sterba # btrfs
Acked-by: Ilya Dryomov # Ceph
Acked-by: Tariq Toukan # mlx4
Acked-by: Leon Romanovsky # mlx5
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: Herbert Xu
Cc: Anton Vorontsov
Cc: Colin Cross
Cc: Tony Luck
Cc: "Rafael J. Wysocki"
Cc: Ben Skeggs
Cc: Kent Overstreet
Cc: Santosh Raspatur
Cc: Hariprasad S
Cc: Yishai Hadas
Cc: Oleg Drokin
Cc: "Yan, Zheng"
Cc: Alexander Viro
Cc: Alexei Starovoitov
Cc: Eric Dumazet
Cc: David Miller
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
getxattr uses vmalloc to allocate memory if kzalloc fails. This is
filled by vfs_getxattr and then copied to the userspace. vmalloc,
however, doesn't zero out the memory so if the specific implementation
of the xattr handler is sloppy we can theoretically expose a kernel
memory. There is no real sign this is really the case but let's make
sure this will not happen and use vzalloc instead.Fixes: 779302e67835 ("fs/xattr.c:getxattr(): improve handling of allocation failures")
Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.org
Acked-by: Kees Cook
Reported-by: Vlastimil Babka
Signed-off-by: Michal Hocko
Cc: [3.6+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Dec, 2016
1 commit
-
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
sed -i -e "s!$PATT!#include !" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)to do the replacement at the end of the merge window.
Requested-by: Al Viro
Signed-off-by: Linus Torvalds
17 Nov, 2016
1 commit
-
The IOP_XATTR flag is set on sockfs because sockfs supports getting the
"system.sockprotoname" xattr. Since commit 6c6ef9f2, this flag is checked for
setxattr support as well. This is wrong on sockfs because security xattr
support there is supposed to be provided by security_inode_setsecurity. The
smack security module relies on socket labels (xattrs).Fix this by adding a security xattr handler on sockfs that returns
-EAGAIN, and by checking for -EAGAIN in setxattr.We cannot simply check for -EOPNOTSUPP in setxattr because there are
filesystems that neither have direct security xattr support nor support
via security_inode_setsecurity. A more proper fix might be to move the
call to security_inode_setsecurity into sockfs, but it's not clear to me
if that is safe: we would end up calling security_inode_post_setxattr after
that as well.Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro
08 Oct, 2016
7 commits
-
These inode operations are no longer used; remove them.
Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro -
All filesystems that support xattrs by now do so via xattr handlers.
They all define sb->s_xattr, and their getxattr, setxattr, and
removexattr inode operations use the generic inode operations. On
filesystems that don't support xattrs, the xattr inode operations are
all NULL, and sb->s_xattr is also NULL.This means that we can remove the getxattr, setxattr, and removexattr
inode operations and directly call the generic handlers, or better,
inline expand those handlers into fs/xattr.c.Filesystems that do not support xattrs on some inodes should clear the
IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems
have checks to disable xattrs on some inodes in the ->list, ->get, and
->set xattr handler operations instead.) The IOP_XATTR flag is
automatically cleared in inodes of filesystems that don't have xattr
support.In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a
check for symlinks to orangefs_inode_getxattr to preserve the current,
weird behavior; that check may not be necessary though.Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro -
When an inode doesn't support xattrs, turn listxattr off as well.
(When xattrs are "turned off", the VFS still passes security xattr
operations through to security modules, which can still expose inode
security labels that way.)Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro -
Right now, various places in the kernel check for the existence of
getxattr, setxattr, and removexattr inode operations and directly call
those operations. Switch to helper functions and test for the IOP_XATTR
flag instead.Signed-off-by: Andreas Gruenbacher
Acked-by: James Morris
Signed-off-by: Al Viro -
With this change, all the xattr handler based operations will produce an
-EIO result for bad inodes, and we no longer only depend on inode->i_op
to be set to bad_inode_ops.Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro -
The IOP_XATTR inode operations flag in inode->i_opflags indicates that
the inode has xattr support. The flag is automatically set by
new_inode() on filesystems with xattr support (where sb->s_xattr is
defined), and cleared otherwise. Filesystems can explicitly clear it
for inodes that should not have xattr support.Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro -
Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro
07 Oct, 2016
1 commit
-
When NULL is passed to one of the xattr system calls as the attribute
name, copying that name from user space already fails with -EFAULT;
xattr_resolve_name is never called with a NULL attribute name.Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro
06 Jul, 2016
1 commit
-
When a filesystem outside of init_user_ns is mounted it could have
uids and gids stored in it that do not map to init_user_ns.The plan is to allow those filesystems to set i_uid to INVALID_UID and
i_gid to INVALID_GID for unmapped uids and gids and then to handle
that strange case in the vfs to ensure there is consistent robust
handling of the weirdness.Upon a careful review of the vfs and filesystems about the only case
where there is any possibility of confusion or trouble is when the
inode is written back to disk. In that case filesystems typically
read the inode->i_uid and inode->i_gid and write them to disk even
when just an inode timestamp is being updated.Which leads to a rule that is very simple to implement and understand
inodes whose i_uid or i_gid is not valid may not be written.In dealing with access times this means treat those inodes as if the
inode flag S_NOATIME was set. Reads of the inodes appear safe and
useful, but any write or modification is disallowed. The only inode
write that is allowed is a chown that sets the uid and gid on the
inode to valid values. After such a chown the inode is normal and may
be treated as such.Denying all writes to inodes with uids or gids unknown to the vfs also
prevents several oddball cases where corruption would have occurred
because the vfs does not have complete information.One problem case that is prevented is attempting to use the gid of a
directory for new inodes where the directories sgid bit is set but the
directories gid is not mapped.Another problem case avoided is attempting to update the evm hash
after setxattr, removexattr, and setattr. As the evm hash includeds
the inode->i_uid or inode->i_gid not knowning the uid or gid prevents
a correct evm hash from being computed. evm hash verification also
fails when i_uid or i_gid is unknown but that is essentially harmless
as it does not cause filesystem corruption.Acked-by: Seth Forshee
Signed-off-by: "Eric W. Biederman"
28 May, 2016
2 commits
-
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.Similar change for ->getxattr() had been done in commit ce23e64. Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.Reported-by: Seung-Woo Kim
Tested-by: Casey Schaufler
Signed-off-by: Al Viro -
preparation for similar switch in ->setxattr() (see the next commit for
rationale).Signed-off-by: Al Viro
26 May, 2016
2 commits
-
Signed-off-by: Al Viro
-
Commit 98e9cb57 improved the xattr name checks in xattr_resolve_name but
didn't update the NULL attribute name check appropriately, so NULL
attribute names lead to NULL pointer dereferences. Turn that into
-EINVAL results instead.Signed-off-by: Andreas Gruenbacher
fs/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Signed-off-by: Al Viro
11 Apr, 2016
2 commits
-
Signed-off-by: Al Viro
-
... and do not assume they are already attached to each other
Signed-off-by: Al Viro
20 Feb, 2016
1 commit
-
The code could leak xattrs->lock on error.
Problem introduced with 786534b92f3ce68f4 "tmpfs: listxattr should
include POSIX ACL xattrs".Signed-off-by: Mateusz Guzik
Signed-off-by: Al Viro
23 Jan, 2016
1 commit
-
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.Signed-off-by: Al Viro
13 Jan, 2016
1 commit
-
Pull misc vfs updates from Al Viro:
"All kinds of stuff. That probably should've been 5 or 6 separate
branches, but by the time I'd realized how large and mixed that bag
had become it had been too close to -final to play with rebasing.Some fs/namei.c cleanups there, memdup_user_nul() introduction and
switching open-coded instances, burying long-dead code, whack-a-mole
of various kinds, several new helpers for ->llseek(), assorted
cleanups and fixes from various people, etc.One piece probably deserves special mention - Neil's
lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets
called without ->i_mutex and tries to avoid ever taking it. That, of
course, means that it's not useful for any directory modifications,
but things like getting inode attributes in nfds readdirplus are fine
with that. I really should've asked for moratorium on lookup-related
changes this cycle, but since I hadn't done that early enough... I
*am* asking for that for the coming cycle, though - I'm going to try
and get conversion of i_mutex to rwsem with ->lookup() done under lock
taken shared.There will be a patch closer to the end of the window, along the lines
of the one Linus had posted last May - mechanical conversion of
->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
inode_is_locked()/inode_lock_nested(). To quote Linus back then:-----
| This is an automated patch using
|
| sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
| sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
| sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
| sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
| sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
|
| with a very few manual fixups
-----I'm going to send that once the ->i_mutex-affecting stuff in -next
gets mostly merged (or when Linus says he's about to stop taking
merges)"* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
nfsd: don't hold i_mutex over userspace upcalls
fs:affs:Replace time_t with time64_t
fs/9p: use fscache mutex rather than spinlock
proc: add a reschedule point in proc_readfd_common()
logfs: constify logfs_block_ops structures
fcntl: allow to set O_DIRECT flag on pipe
fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
fs: xattr: Use kvfree()
[s390] page_to_phys() always returns a multiple of PAGE_SIZE
nbd: use ->compat_ioctl()
fs: use block_device name vsprintf helper
lib/vsprintf: add %*pg format specifier
fs: use gendisk->disk_name where possible
poll: plug an unused argument to do_poll
amdkfd: don't open-code memdup_user()
cdrom: don't open-code memdup_user()
rsxx: don't open-code memdup_user()
mtip32xx: don't open-code memdup_user()
[um] mconsole: don't open-code memdup_user_nul()
[um] hostaudio: don't open-code memdup_user()
...
09 Jan, 2016
1 commit
-
... instead of open coding it.
Signed-off-by: Richard Weinberger
Signed-off-by: Al Viro
14 Dec, 2015
2 commits
-
Change the list operation to only return whether or not an attribute
should be listed. Copying the attribute names into the buffer is moved
to the callers.Since the result only depends on the dentry and not on the attribute
name, we do not pass the attribute name to list operations.Signed-off-by: Andreas Gruenbacher
Signed-off-by: Al Viro -
Add a nfs_listxattr operation. Move the call to security_inode_listsecurity
from list operation of the "security.*" xattr handler to nfs_listxattr.Signed-off-by: Andreas Gruenbacher
Cc: Trond Myklebust
Cc: Anna Schumaker
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Al Viro
07 Dec, 2015
4 commits
-
When a file on tmpfs has an ACL or a Default ACL, listxattr should include the
corresponding xattr name.Signed-off-by: Andreas Gruenbacher
Reviewed-by: James Morris
Cc: Hugh Dickins
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro -
Use the VFS xattr handler infrastructure and get rid of similar code in
the filesystem. For implementing shmem_xattr_handler_set, we need a
version of simple_xattr_set which removes the attribute when value is
NULL. Use this to implement kernfs_iop_removexattr as well.Signed-off-by: Andreas Gruenbacher
Reviewed-by: James Morris
Cc: Hugh Dickins
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro -
Add an additional "name" field to struct xattr_handler. When the name
is set, the handler matches attributes with exactly that name. When the
prefix is set instead, the handler matches attributes with the given
prefix and with a non-empty suffix.This patch should avoid bugs like the one fixed in commit c361016a in
the future.Signed-off-by: Andreas Gruenbacher
Reviewed-by: James Morris
Signed-off-by: Al Viro -
This function was only briefly used in security/integrity/evm, between
commits 66dbc325 and 15647eb3.Signed-off-by: Andreas Gruenbacher
Reviewed-by: James Morris
Signed-off-by: Al Viro
14 Nov, 2015
2 commits
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Now that the xattr handler is passed to the xattr handler operations, we
can use the same get and set operations for the user, trusted, and security
xattr namespaces. In those namespaces, we can access the full attribute
name by "reattaching" the name prefix the vfs has skipped for us. Add a
xattr_full_name helper to make this obvious in the code.For the "system.posix_acl_access" and "system.posix_acl_default"
attributes, handler->prefix is the full attribute name; the suffix is the
empty string.Signed-off-by: Andreas Gruenbacher
Cc: Eric Van Hensbergen
Cc: Ron Minnich
Cc: Latchesar Ionkov
Cc: v9fs-developer@lists.sourceforge.net
Signed-off-by: Al Viro -
The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example. In some oprations, it would be useful to also have
access to the handler prefix. To allow that, pass a pointer to the handler
to operations instead of the flags value alone.Signed-off-by: Andreas Gruenbacher
Reviewed-by: Christoph Hellwig
Signed-off-by: Al Viro
22 May, 2015
1 commit
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EVM needs to be atomically updated when removing xattrs.
Otherwise concurrent EVM verification may fail in between.
This patch fixes by moving i_mutex unlocking after calling
EVM hook. fsnotify_xattr() is also now called while locked
the same way as it is done in __vfs_setxattr_noperm.Changelog:
- remove unused 'inode' variable.Signed-off-by: Dmitry Kasatkin
Signed-off-by: Mimi Zohar
20 Nov, 2014
1 commit
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... for situations when we don't have any candidate in pathnames - basically,
in descriptor-based syscalls.[Folded the build fix for !CONFIG_AUDITSYSCALL configs from Chen Gang]
Signed-off-by: Al Viro
13 Oct, 2014
1 commit
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The following pairs of system calls dealing with extended attributes only
differ in their behavior on whether the symbolic link is followed (when
the named file is a symbolic link):- setxattr() and lsetxattr()
- getxattr() and lgetxattr()
- listxattr() and llistxattr()
- removexattr() and lremovexattr()Despite this, the implementations all had duplicated code, so this commit
redirects each of the above pairs of system calls to a corresponding
function to which different lookup flags (LOOKUP_FOLLOW or 0) are passed.For me this reduced the stripped size of xattr.o from 8824 to 8248 bytes.
Signed-off-by: Eric Biggers
Signed-off-by: Al Viro
