Fix memory leak in smack_inode_getsecctx
The implementation of smack_inode_getsecctx() made
incorrect assumptions about how Smack presents a security
context. Smack does not need to allocate memory to support
security contexts, so "releasing" a Smack context is a no-op.
The code made an unnecessary copy and returned that as a
context, which was never freed. The revised implementation
returns the context correctly.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: CHANDAN VN <chandan.vn@samsung.com>
Tested-by: CHANDAN VN <chandan.vn@samsung.com>
Pull userns updates from Eric Biederman:
"This is the last couple of vfs bits to enable root in a user namespace
to mount and manipulate a filesystem with backing store (AKA not a
virtual filesystem like proc, but a filesystem where the unprivileged
user controls the content). The target filesystem for this work is
fuse, and Miklos should be sending you the pull request for the fuse
bits this merge window.
The two key patches are "evm: Don't update hmacs in user ns mounts"
and "vfs: Don't allow changing the link count of an inode with an
invalid uid or gid". Those close small gaps in the vfs that would be a
problem if an unprivileged fuse filesystem is mounted.
The rest of the changes are things that are now safe to allow a root
user in a user namespace to do with a filesystem they have mounted.
The most interesting development is that remount is now safe"
* 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems
capabilities: Allow privileged user in s_user_ns to set security.* xattrs
fs: Allow superblock owner to access do_remount_sb()
fs: Allow superblock owner to replace invalid owners of inodes
vfs: Allow userns root to call mknod on owned filesystems.
vfs: Don't allow changing the link count of an inode with an invalid uid or gid
evm: Don't update hmacs in user ns mounts
Pull misc vfs updates from Al Viro:
"Misc bits and pieces not fitting into anything more specific"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: delete unnecessary assignment in vfs_listxattr
Documentation: filesystems: update filesystem locking documentation
vfs: namei: use path_equal() in follow_dotdot()
fs.h: fix outdated comment about file flags
__inode_security_revalidate() never gets NULL opt_dentry
make xattr_getsecurity() static
vfat: simplify checks in vfat_lookup()
get rid of dead code in d_find_alias()
it's SB_BORN, not MS_BORN...
msdos_rmdir(): kill BS comment
remove rpc_rmdir()
fs: avoid fdput() after failed fdget() in vfs_dedupe_file_range()
Filling in the padding slot in the bpf structure as a bug fix in 'ne'
overlapped with actually using that padding area for something in
'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to unlock before returning on this error path.
Fixes: fa516b66a1 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
If the user sets xattr->name[0] to NUL then we would read one character
before the start of the array. This bug seems harmless as far as I can
see but perhaps it would trigger a warning in KASAN.
Fixes: fa516b66a1 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
In the case where the allocation of xattr fails and xattr is NULL, the
error exit return path via label 'out' will dereference xattr when
kfree'ing xattr-name. Fix this by only kfree'ing xattr->name and xattr
when xattr is non-null.
Detected by CoverityScan, CID#1469366 ("Dereference after null check")
Fixes: fa516b66a1 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
The allocation of 'temp' is not kfree'd and hence there is a memory
leak on each call of evm_read_xattrs. Fix this by kfree'ing it
after copying data from it back to the user space buffer 'buf'.
Detected by CoverityScan, CID#1469386 ("Resource Leak")
Fixes: fa516b66a1 ("EVM: Allow runtime modification of the set of verified xattrs")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Use list_splice_tail_init_rcu() to extend the existing custom IMA policy
with additional IMA policy rules.
Signed-off-by: Petko Manolov <petko.manolov@konsulko.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Pull SELinux fix from Paul Moore:
"One more small fix for SELinux: a small string length fix found by
KASAN.
I dislike sending patches this late in the release cycle, but this
patch fixes a legitimate problem, is very small, limited in scope, and
well understood.
There are two threads with more information on the problem, the latest
is linked below:
https://marc.info/?t=152723737400001&r=1&w=2
Stephen points out in the thread linked above:
'Such a setxattr() call can only be performed by a process with
CAP_MAC_ADMIN that is also allowed mac_admin permission in SELinux
policy. Consequently, this is never possible on Android (no process
is allowed mac_admin permission, always enforcing) and is only
possible in Fedora/RHEL for a few domains (if enforcing)'"
* tag 'selinux-pr-20180530' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: KASAN: slab-out-of-bounds in xattr_getsecurity
Call trace:
[<ffffff9203a8d7a8>] dump_backtrace+0x0/0x428
[<ffffff9203a8dbf8>] show_stack+0x28/0x38
[<ffffff920409bfb8>] dump_stack+0xd4/0x124
[<ffffff9203d187e8>] print_address_description+0x68/0x258
[<ffffff9203d18c00>] kasan_report.part.2+0x228/0x2f0
[<ffffff9203d1927c>] kasan_report+0x5c/0x70
[<ffffff9203d1776c>] check_memory_region+0x12c/0x1c0
[<ffffff9203d17cdc>] memcpy+0x34/0x68
[<ffffff9203d75348>] xattr_getsecurity+0xe0/0x160
[<ffffff9203d75490>] vfs_getxattr+0xc8/0x120
[<ffffff9203d75d68>] getxattr+0x100/0x2c8
[<ffffff9203d76fb4>] SyS_fgetxattr+0x64/0xa0
[<ffffff9203a83f70>] el0_svc_naked+0x24/0x28
If user get root access and calls security.selinux setxattr() with an
embedded NUL on a file and then if some process performs a getxattr()
on that file with a length greater than the actual length of the string,
it would result in a panic.
To fix this, add the actual length of the string to the security context
instead of the length passed by the userspace process.
Signed-off-by: Sachin Grover <sgrover@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <paul@paul-moore.com>
A privileged user in s_user_ns will generally have the ability to
manipulate the backing store and insert security.* xattrs into
the filesystem directly. Therefore the kernel must be prepared to
handle these xattrs from unprivileged mounts, and it makes little
sense for commoncap to prevent writing these xattrs to the
filesystem. The capability and LSM code have already been updated
to appropriately handle xattrs from unprivileged mounts, so it
is safe to loosen this restriction on setting xattrs.
The exception to this logic is that writing xattrs to a mounted
filesystem may also cause the LSM inode_post_setxattr or
inode_setsecurity callbacks to be invoked. SELinux will deny the
xattr update by virtue of applying mountpoint labeling to
unprivileged userns mounts, and Smack will deny the writes for
any user without global CAP_MAC_ADMIN, so loosening the
capability check in commoncap is safe in this respect as well.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
As IMA policy rules are added, a mask of the type of rule (eg. kernel
modules, firmware, IMA policy) is updated. Unlike custom IMA policy
rules, which replace the original builtin policy rules and update the
mask, the builtin "secure_boot" policy rules were loaded, but did not
update the mask.
This patch refactors the code to load custom policies, defining a new
function named ima_appraise_flag(). The new function is called either
when loading the builtin "secure_boot" or custom policies.
Fixes: 503ceaef8e ("ima: define a set of appraisal rules requiring file signatures")
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
If/when file data signatures are distributed with the file data, this
patch will not be needed. In the current environment where only some
files are signed, the ability to differentiate between file systems is
needed. Some file systems consider the file system magic number
internal to the file system.
This patch defines a new IMA policy condition named "fsname", based on
the superblock's file_system_type (sb->s_type) name. This allows policy
rules to be expressed in terms of the filesystem name.
The following sample rules require file signatures on rootfs files
executed or mmap'ed.
appraise func=BPRM_CHECK fsname=rootfs appraise_type=imasig
appraise func=FILE_MMAP fsname=rootfs appraise_type=imasig
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull vfs fixes from Al Viro:
"Assorted fixes all over the place"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
aio: fix io_destroy(2) vs. lookup_ioctx() race
ext2: fix a block leak
nfsd: vfs_mkdir() might succeed leaving dentry negative unhashed
cachefiles: vfs_mkdir() might succeed leaving dentry negative unhashed
unfuck sysfs_mount()
kernfs: deal with kernfs_fill_super() failures
cramfs: Fix IS_ENABLED typo
befs_lookup(): use d_splice_alias()
affs_lookup: switch to d_splice_alias()
affs_lookup(): close a race with affs_remove_link()
fix breakage caused by d_find_alias() semantics change
fs: don't scan the inode cache before SB_BORN is set
do d_instantiate/unlock_new_inode combinations safely
iov_iter: fix memory leak in pipe_get_pages_alloc()
iov_iter: fix return type of __pipe_get_pages()
Sites may wish to provide additional metadata alongside files in order
to make more fine-grained security decisions[1]. The security of this is
enhanced if this metadata is protected, something that EVM makes
possible. However, the kernel cannot know about the set of extended
attributes that local admins may wish to protect, and hardcoding this
policy in the kernel makes it difficult to change over time and less
convenient for distributions to enable.
This patch adds a new /sys/kernel/security/integrity/evm/evm_xattrs node,
which can be read to obtain the current set of EVM-protected extended
attributes or written to in order to add new entries. Extending this list
will not change the validity of any existing signatures provided that the
file in question does not have any of the additional extended attributes -
missing xattrs are skipped when calculating the EVM hash.
[1] For instance, a package manager could install information about the
package uploader in an additional extended attribute. Local LSM policy
could then be associated with that extended attribute in order to
restrict the privileges available to packages from less trusted
uploaders.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Pull SELinux fixes from Paul Moore:
"A small pull request to fix a few regressions in the SELinux/SCTP code
with applications that call bind() with AF_UNSPEC/INADDR_ANY.
The individual commit descriptions have more information, but the
commits themselves should be self explanatory"
* tag 'selinux-pr-20180516' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: correctly handle sa_family cases in selinux_sctp_bind_connect()
selinux: fix address family in bind() and connect() to match address/port
selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind()
We want to add additional evm control nodes, and it'd be preferable not
to clutter up the securityfs root directory any further. Create a new
integrity directory, move the ima directory into it, create an evm
directory for the evm attribute and add compatibility symlinks.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
James Morris
Casey Schaufler
Linus Torvalds
David S. Miller
Dan Carpenter
Colin Ian King
Petko Manolov
Yisheng Xie
Sachin Grover
Eric W. Biederman
Mimi Zohar
Matthew Garrett