- 15 12月, 2012 1 次提交
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由 Eric W. Biederman 提交于
Andy Lutomirski <luto@amacapital.net> found a nasty little bug in the permissions of setns. With unprivileged user namespaces it became possible to create new namespaces without privilege. However the setns calls were relaxed to only require CAP_SYS_ADMIN in the user nameapce of the targed namespace. Which made the following nasty sequence possible. pid = clone(CLONE_NEWUSER | CLONE_NEWNS); if (pid == 0) { /* child */ system("mount --bind /home/me/passwd /etc/passwd"); } else if (pid != 0) { /* parent */ char path[PATH_MAX]; snprintf(path, sizeof(path), "/proc/%u/ns/mnt"); fd = open(path, O_RDONLY); setns(fd, 0); system("su -"); } Prevent this possibility by requiring CAP_SYS_ADMIN in the current user namespace when joing all but the user namespace. Acked-by: NSerge Hallyn <serge.hallyn@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
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- 20 11月, 2012 1 次提交
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由 Eric W. Biederman 提交于
Assign a unique proc inode to each namespace, and use that inode number to ensure we only allocate at most one proc inode for every namespace in proc. A single proc inode per namespace allows userspace to test to see if two processes are in the same namespace. This has been a long requested feature and only blocked because a naive implementation would put the id in a global space and would ultimately require having a namespace for the names of namespaces, making migration and certain virtualization tricks impossible. We still don't have per superblock inode numbers for proc, which appears necessary for application unaware checkpoint/restart and migrations (if the application is using namespace file descriptors) but that is now allowd by the design if it becomes important. I have preallocated the ipc and uts initial proc inode numbers so their structures can be statically initialized. Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
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- 19 11月, 2012 5 次提交
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由 Zhao Hongjiang 提交于
Change return value from -EINVAL to -EPERM when the permission check fails. Signed-off-by: NZhao Hongjiang <zhaohongjiang@huawei.com> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
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由 Eric W. Biederman 提交于
- Add a filesystem flag to mark filesystems that are safe to mount as an unprivileged user. - Add a filesystem flag to mark filesystems that don't need MNT_NODEV when mounted by an unprivileged user. - Relax the permission checks to allow unprivileged users that have CAP_SYS_ADMIN permissions in the user namespace referred to by the current mount namespace to be allowed to mount, unmount, and move filesystems. Acked-by: N"Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
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由 Eric W. Biederman 提交于
Sharing mount subtress with mount namespaces created by unprivileged users allows unprivileged mounts created by unprivileged users to propagate to mount namespaces controlled by privileged users. Prevent nasty consequences by changing shared subtrees to slave subtress when an unprivileged users creates a new mount namespace. Acked-by: NSerge Hallyn <serge.hallyn@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
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由 Eric W. Biederman 提交于
This will allow for support for unprivileged mounts in a new user namespace. Acked-by: N"Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
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由 Eric W. Biederman 提交于
setns support for the mount namespace is a little tricky as an arbitrary decision must be made about what to set fs->root and fs->pwd to, as there is no expectation of a relationship between the two mount namespaces. Therefore I arbitrarily find the root mount point, and follow every mount on top of it to find the top of the mount stack. Then I set fs->root and fs->pwd to that location. The topmost root of the mount stack seems like a reasonable place to be. Bind mount support for the mount namespace inodes has the possibility of creating circular dependencies between mount namespaces. Circular dependencies can result in loops that prevent mount namespaces from every being freed. I avoid creating those circular dependencies by adding a sequence number to the mount namespace and require all bind mounts be of a younger mount namespace into an older mount namespace. Add a helper function proc_ns_inode so it is possible to detect when we are attempting to bind mound a namespace inode. Acked-by: NSerge Hallyn <serge.hallyn@canonical.com> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
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- 13 10月, 2012 1 次提交
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由 Jeff Layton 提交于
getname() is intended to copy pathname strings from userspace into a kernel buffer. The result is just a string in kernel space. It would however be quite helpful to be able to attach some ancillary info to the string. For instance, we could attach some audit-related info to reduce the amount of audit-related processing needed. When auditing is enabled, we could also call getname() on the string more than once and not need to recopy it from userspace. This patchset converts the getname()/putname() interfaces to return a struct instead of a string. For now, the struct just tracks the string in kernel space and the original userland pointer for it. Later, we'll add other information to the struct as it becomes convenient. Signed-off-by: NJeff Layton <jlayton@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 12 10月, 2012 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 23 9月, 2012 1 次提交
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由 Al Viro 提交于
normally we deal with lock_mount()/umount races by checking that mountpoint to be is still in our namespace after lock_mount() has been done. However, do_add_mount() skips that check when called with MNT_SHRINKABLE in flags (i.e. from finish_automount()). The reason is that ->mnt_ns may be a temporary namespace created exactly to contain automounts a-la NFS4 referral handling. It's not the namespace of the caller, though, so check_mnt() would fail here. We still need to check that ->mnt_ns is non-NULL in that case, though. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 31 7月, 2012 1 次提交
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由 Jan Kara 提交于
Most of places where we want freeze protection coincides with the places where we also have remount-ro protection. So make mnt_want_write() and mnt_drop_write() (and their _file alternative) prevent freezing as well. For the few cases that are really interested only in remount-ro protection provide new function variants. BugLink: https://bugs.launchpad.net/bugs/897421Tested-by: NKamal Mostafa <kamal@canonical.com> Tested-by: NPeter M. Petrakis <peter.petrakis@canonical.com> Tested-by: NDann Frazier <dann.frazier@canonical.com> Tested-by: NMassimo Morana <massimo.morana@canonical.com> Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 14 7月, 2012 4 次提交
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由 David Howells 提交于
Add comments describing what the directions "up" and "down" mean and ref count handling to the VFS mount following family of functions. Signed-off-by: Valerie Aurora <vaurora@redhat.com> (Original author) Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 David Howells 提交于
copy_tree() can theoretically fail in a case other than ENOMEM, but always returns NULL which is interpreted by callers as -ENOMEM. Change it to return an explicit error. Also change clone_mnt() for consistency and because union mounts will add new error cases. Thanks to Andreas Gruenbacher <agruen@suse.de> for a bug fix. [AV: folded braino fix by Dan Carpenter] Original-author: Valerie Aurora <vaurora@redhat.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Cc: Valerie Aurora <valerie.aurora@gmail.com> Cc: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
don't rely on proc_mounts->m being the first field; container_of() is there for purpose. No need to bother with ->private, while we are at it - the same container_of will do nicely. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
it's enough to set ->mnt_ns of internal vfsmounts to something distinct from all struct mnt_namespace out there; then we can just use the check for ->mnt_ns != NULL in the fast path of mntput_no_expire() Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 31 5月, 2012 1 次提交
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由 Al Viro 提交于
__mnt_make_shortterm() in there undoes the effect of __mnt_make_longterm() we'd done back when we set ->mnt_ns non-NULL; it should not be done to vfsmounts that had never gone through commit_tree() and friends. Kudos to lczerner for catching that one... Cc: stable@vger.kernel.org Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 30 5月, 2012 1 次提交
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由 Andi Kleen 提交于
lglocks and brlocks are currently generated with some complicated macros in lglock.h. But there's no reason to not just use common utility functions and put all the data into a common data structure. In preparation, this patch changes the API to look more like normal function calls with pointers, not magic macros. The patch is rather large because I move over all users in one go to keep it bisectable. This impacts the VFS somewhat in terms of lines changed. But no actual behaviour change. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: NAndi Kleen <ak@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 07 1月, 2012 4 次提交
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由 Miklos Szeredi 提交于
If there are any inodes on the super block that have been unlinked (i_nlink == 0) but have not yet been deleted then prevent the remounting the super block read-only. Reported-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz> Tested-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Miklos Szeredi 提交于
Currently remouting superblock read-only is racy in a major way. With the per mount read-only infrastructure it is now possible to prevent most races, which this patch attempts. Before starting the remount read-only, iterate through all mounts belonging to the superblock and if none of them have any pending writes, set sb->s_readonly_remount. This indicates that remount is in progress and no further write requests are allowed. If the remount succeeds set MS_RDONLY and reset s_readonly_remount. If the remounting is unsuccessful just reset s_readonly_remount. This can result in transient EROFS errors, despite the fact the remount failed. Unfortunately hodling off writes is difficult as remount itself may touch the filesystem (e.g. through load_nls()) which would deadlock. A later patch deals with delayed writes due to nlink going to zero. Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz> Tested-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Miklos Szeredi 提交于
Keep track of vfsmounts belonging to a superblock. List is protected by vfsmount_lock. Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz> Tested-by: NToshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 04 1月, 2012 19 次提交
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由 Al Viro 提交于
[folded fix for missing magic.h from Tetsuo Handa] Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
rationale: that stuff is far tighter bound to fs/namespace.c than to the guts of procfs proper. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
make IS_MNT_SLAVE take struct mount * at the same time Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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