- 07 7月, 2017 1 次提交
-
-
由 Pavel Tatashin 提交于
Update dcache, inode, pid, mountpoint, and mount hash tables to use HASH_ZERO, and remove initialization after allocations. In case of places where HASH_EARLY was used such as in __pv_init_lock_hash the zeroed hash table was already assumed, because memblock zeroes the memory. CPU: SPARC M6, Memory: 7T Before fix: Dentry cache hash table entries: 1073741824 Inode-cache hash table entries: 536870912 Mount-cache hash table entries: 16777216 Mountpoint-cache hash table entries: 16777216 ftrace: allocating 20414 entries in 40 pages Total time: 11.798s After fix: Dentry cache hash table entries: 1073741824 Inode-cache hash table entries: 536870912 Mount-cache hash table entries: 16777216 Mountpoint-cache hash table entries: 16777216 ftrace: allocating 20414 entries in 40 pages Total time: 3.198s CPU: Intel Xeon E5-2630, Memory: 2.2T: Before fix: Dentry cache hash table entries: 536870912 Inode-cache hash table entries: 268435456 Mount-cache hash table entries: 8388608 Mountpoint-cache hash table entries: 8388608 CPU: Physical Processor ID: 0 Total time: 3.245s After fix: Dentry cache hash table entries: 536870912 Inode-cache hash table entries: 268435456 Mount-cache hash table entries: 8388608 Mountpoint-cache hash table entries: 8388608 CPU: Physical Processor ID: 0 Total time: 3.244s Link: http://lkml.kernel.org/r/1488432825-92126-4-git-send-email-pasha.tatashin@oracle.comSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: NBabu Moger <babu.moger@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 15 6月, 2017 1 次提交
-
-
由 Andrei Vagin 提交于
Fixes: 4f757f3c ("make sure that mntns_install() doesn't end up with referral for root") Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrei Vagin <avagin@openvz.org> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 23 5月, 2017 2 次提交
-
-
由 Eric W. Biederman 提交于
While investigating some poor umount performance I realized that in the case of overlapping mount trees where some of the mounts are locked the code has been failing to unmount all of the mounts it should have been unmounting. This failure to unmount all of the necessary mounts can be reproduced with: $ cat locked_mounts_test.sh mount -t tmpfs test-base /mnt mount --make-shared /mnt mkdir -p /mnt/b mount -t tmpfs test1 /mnt/b mount --make-shared /mnt/b mkdir -p /mnt/b/10 mount -t tmpfs test2 /mnt/b/10 mount --make-shared /mnt/b/10 mkdir -p /mnt/b/10/20 mount --rbind /mnt/b /mnt/b/10/20 unshare -Urm --propagation unchaged /bin/sh -c 'sleep 5; if [ $(grep test /proc/self/mountinfo | wc -l) -eq 1 ] ; then echo SUCCESS ; else echo FAILURE ; fi' sleep 1 umount -l /mnt/b wait %% $ unshare -Urm ./locked_mounts_test.sh This failure is corrected by removing the prepass that marks mounts that may be umounted. A first pass is added that umounts mounts if possible and if not sets mount mark if they could be unmounted if they weren't locked and adds them to a list to umount possibilities. This first pass reconsiders the mounts parent if it is on the list of umount possibilities, ensuring that information of umoutability will pass from child to mount parent. A second pass then walks through all mounts that are umounted and processes their children unmounting them or marking them for reparenting. A last pass cleans up the state on the mounts that could not be umounted and if applicable reparents them to their first parent that remained mounted. While a bit longer than the old code this code is much more robust as it allows information to flow up from the leaves and down from the trunk making the order in which mounts are encountered in the umount propgation tree irrelevant. Cc: stable@vger.kernel.org Fixes: 0c56fe31 ("mnt: Don't propagate unmounts to locked mounts") Reviewed-by: NAndrei Vagin <avagin@virtuozzo.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
It was observed that in some pathlogical cases that the current code does not unmount everything it should. After investigation it was determined that the issue is that mnt_change_mntpoint can can change which mounts are available to be unmounted during mount propagation which is wrong. The trivial reproducer is: $ cat ./pathological.sh mount -t tmpfs test-base /mnt cd /mnt mkdir 1 2 1/1 mount --bind 1 1 mount --make-shared 1 mount --bind 1 2 mount --bind 1/1 1/1 mount --bind 1/1 1/1 echo grep test-base /proc/self/mountinfo umount 1/1 echo grep test-base /proc/self/mountinfo $ unshare -Urm ./pathological.sh The expected output looks like: 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 49 54 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 50 53 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 51 49 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 54 47 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 53 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 52 50 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 The output without the fix looks like: 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 49 54 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 50 53 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 51 49 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 54 47 0:25 /1/1 /mnt/1/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 53 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 52 50 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 46 31 0:25 / /mnt rw,relatime - tmpfs test-base rw,uid=1000,gid=1000 47 46 0:25 /1 /mnt/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 48 46 0:25 /1 /mnt/2 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 52 48 0:25 /1/1 /mnt/2/1 rw,relatime shared:1 - tmpfs test-base rw,uid=1000,gid=1000 That last mount in the output was in the propgation tree to be unmounted but was missed because the mnt_change_mountpoint changed it's parent before the walk through the mount propagation tree observed it. Cc: stable@vger.kernel.org Fixes: 1064f874 ("mnt: Tuck mounts under others instead of creating shadow/side mounts.") Acked-by: NAndrei Vagin <avagin@virtuozzo.com> Reviewed-by: NRam Pai <linuxram@us.ibm.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 22 4月, 2017 1 次提交
-
-
由 Al Viro 提交于
new flag: LOOKUP_DOWN. If the starting point is overmounted, cross into whatever's mounted on top, triggering referrals et.al. Use that instead of follow_down_one() loop in mntns_install(), handle errors properly. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 10 4月, 2017 2 次提交
-
-
由 Jan Kara 提交于
Currently we free fsnotify_mark_connector structure only when inode / vfsmount is getting freed. This can however impose noticeable memory overhead when marks get attached to inodes only temporarily. So free the connector structure once the last mark is detached from the object. Since notification infrastructure can be working with the connector under the protection of fsnotify_mark_srcu, we have to be careful and free the fsnotify_mark_connector only after SRCU period passes. Reviewed-by: NMiklos Szeredi <mszeredi@redhat.com> Reviewed-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NJan Kara <jack@suse.cz>
-
由 Jan Kara 提交于
Currently notification marks are attached to object (inode or vfsmnt) by a hlist_head in the object. The list is also protected by a spinlock in the object. So while there is any mark attached to the list of marks, the object must be pinned in memory (and thus e.g. last iput() deleting inode cannot happen). Also for list iteration in fsnotify() to work, we must hold fsnotify_mark_srcu lock so that mark itself and mark->obj_list.next cannot get freed. Thus we are required to wait for response to fanotify events from userspace process with fsnotify_mark_srcu lock held. That causes issues when userspace process is buggy and does not reply to some event - basically the whole notification subsystem gets eventually stuck. So to be able to drop fsnotify_mark_srcu lock while waiting for response, we have to pin the mark in memory and make sure it stays in the object list (as removing the mark waiting for response could lead to lost notification events for groups later in the list). However we don't want inode reclaim to block on such mark as that would lead to system just locking up elsewhere. This commit is the first in the series that paves way towards solving these conflicting lifetime needs. Instead of anchoring the list of marks directly in the object, we anchor it in a dedicated structure (fsnotify_mark_connector) and just point to that structure from the object. The following commits will also add spinlock protecting the list and object pointer to the structure. Reviewed-by: NMiklos Szeredi <mszeredi@redhat.com> Reviewed-by: NAmir Goldstein <amir73il@gmail.com> Signed-off-by: NJan Kara <jack@suse.cz>
-
- 02 3月, 2017 2 次提交
-
-
由 Ingo Molnar 提交于
sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> Update all usage sites first. Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Ingo Molnar 提交于
Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
- 03 2月, 2017 1 次提交
-
-
由 Eric W. Biederman 提交于
Ever since mount propagation was introduced in cases where a mount in propagated to parent mount mountpoint pair that is already in use the code has placed the new mount behind the old mount in the mount hash table. This implementation detail is problematic as it allows creating arbitrary length mount hash chains. Furthermore it invalidates the constraint maintained elsewhere in the mount code that a parent mount and a mountpoint pair will have exactly one mount upon them. Making it hard to deal with and to talk about this special case in the mount code. Modify mount propagation to notice when there is already a mount at the parent mount and mountpoint where a new mount is propagating to and place that preexisting mount on top of the new mount. Modify unmount propagation to notice when a mount that is being unmounted has another mount on top of it (and no other children), and to replace the unmounted mount with the mount on top of it. Move the MNT_UMUONT test from __lookup_mnt_last into __propagate_umount as that is the only call of __lookup_mnt_last where MNT_UMOUNT may be set on any mount visible in the mount hash table. These modifications allow: - __lookup_mnt_last to be removed. - attach_shadows to be renamed __attach_mnt and its shadow handling to be removed. - commit_tree to be simplified - copy_tree to be simplified The result is an easier to understand tree of mounts that does not allow creation of arbitrary length hash chains in the mount hash table. The result is also a very slight userspace visible difference in semantics. The following two cases now behave identically, where before order mattered: case 1: (explicit user action) B is a slave of A mount something on A/a , it will propagate to B/a and than mount something on B/a case 2: (tucked mount) B is a slave of A mount something on B/a and than mount something on A/a Histroically umount A/a would fail in case 1 and succeed in case 2. Now umount A/a succeeds in both configurations. This very small change in semantics appears if anything to be a bug fix to me and my survey of userspace leads me to believe that no programs will notice or care of this subtle semantic change. v2: Updated to mnt_change_mountpoint to not call dput or mntput and instead to decrement the counts directly. It is guaranteed that there will be other references when mnt_change_mountpoint is called so this is safe. v3: Moved put_mountpoint under mount_lock in attach_recursive_mnt As the locking in fs/namespace.c changed between v2 and v3. v4: Reworked the logic in propagate_mount_busy and __propagate_umount that detects when a mount completely covers another mount. v5: Removed unnecessary tests whose result is alwasy true in find_topper and attach_recursive_mnt. v6: Document the user space visible semantic difference. Cc: stable@vger.kernel.org Fixes: b90fa9ae ("[PATCH] shared mount handling: bind and rbind") Tested-by: NAndrei Vagin <avagin@virtuozzo.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 01 2月, 2017 1 次提交
-
-
由 Eric W. Biederman 提交于
To support unprivileged users mounting filesystems two permission checks have to be performed: a test to see if the user allowed to create a mount in the mount namespace, and a test to see if the user is allowed to access the specified filesystem. The automount case is special in that mounting the original filesystem grants permission to mount the sub-filesystems, to any user who happens to stumble across the their mountpoint and satisfies the ordinary filesystem permission checks. Attempting to handle the automount case by using override_creds almost works. It preserves the idea that permission to mount the original filesystem is permission to mount the sub-filesystem. Unfortunately using override_creds messes up the filesystems ordinary permission checks. Solve this by being explicit that a mount is a submount by introducing vfs_submount, and using it where appropriate. vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let sget and friends know that a mount is a submount so they can take appropriate action. sget and sget_userns are modified to not perform any permission checks on submounts. follow_automount is modified to stop using override_creds as that has proven problemantic. do_mount is modified to always remove the new MS_SUBMOUNT flag so that we know userspace will never by able to specify it. autofs4 is modified to stop using current_real_cred that was put in there to handle the previous version of submount permission checking. cifs is modified to pass the mountpoint all of the way down to vfs_submount. debugfs is modified to pass the mountpoint all of the way down to trace_automount by adding a new parameter. To make this change easier a new typedef debugfs_automount_t is introduced to capture the type of the debugfs automount function. Cc: stable@vger.kernel.org Fixes: 069d5ac9 ("autofs: Fix automounts by using current_real_cred()->uid") Fixes: aeaa4a79 ("fs: Call d_automount with the filesystems creds") Reviewed-by: NTrond Myklebust <trond.myklebust@primarydata.com> Reviewed-by: NSeth Forshee <seth.forshee@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 10 1月, 2017 1 次提交
-
-
由 Eric W. Biederman 提交于
Protecting the mountpoint hashtable with namespace_sem was sufficient until a call to umount_mnt was added to mntput_no_expire. At which point it became possible for multiple calls of put_mountpoint on the same hash chain to happen on the same time. Kristen Johansen <kjlx@templeofstupid.com> reported: > This can cause a panic when simultaneous callers of put_mountpoint > attempt to free the same mountpoint. This occurs because some callers > hold the mount_hash_lock, while others hold the namespace lock. Some > even hold both. > > In this submitter's case, the panic manifested itself as a GP fault in > put_mountpoint() when it called hlist_del() and attempted to dereference > a m_hash.pprev that had been poisioned by another thread. Al Viro observed that the simple fix is to switch from using the namespace_sem to the mount_lock to protect the mountpoint hash table. I have taken Al's suggested patch moved put_mountpoint in pivot_root (instead of taking mount_lock an additional time), and have replaced new_mountpoint with get_mountpoint a function that does the hash table lookup and addition under the mount_lock. The introduction of get_mounptoint ensures that only the mount_lock is needed to manipulate the mountpoint hashtable. d_set_mounted is modified to only set DCACHE_MOUNTED if it is not already set. This allows get_mountpoint to use the setting of DCACHE_MOUNTED to ensure adding a struct mountpoint for a dentry happens exactly once. Cc: stable@vger.kernel.org Fixes: ce07d891 ("mnt: Honor MNT_LOCKED when detaching mounts") Reported-by: NKrister Johansen <kjlx@templeofstupid.com> Suggested-by: NAl Viro <viro@ZenIV.linux.org.uk> Acked-by: NAl Viro <viro@ZenIV.linux.org.uk> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 17 12月, 2016 3 次提交
-
-
由 Al Viro 提交于
Make sure that clone_mnt() never returns a mount with MNT_SHARED in flags, but without a valid ->mnt_group_id. That allows to demystify do_make_slave() quite a bit, among other things. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
由 Al Viro 提交于
not for CL_PRIVATE clone_mnt() Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
由 Al Viro 提交于
Hadn't been true for quite a while Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 06 12月, 2016 2 次提交
-
-
由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
由 Mickaël Salaün 提交于
The function path_is_under() doesn't modify the paths pointed by its arguments but only browse them. Constifying this pointers make a cleaner interface to be used by (future) code which may only have access to const struct path pointers (e.g. LSM hooks). Signed-off-by: NMickaël Salaün <mic@digikod.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 04 12月, 2016 1 次提交
-
-
由 Ian Kent 提交于
d_mountpoint() can only be used reliably to establish if a dentry is not mounted in any namespace. It isn't aware of the possibility there may be multiple mounts using a given dentry that may be in a different namespace. Add helper functions, path_is_mountpoint(), that checks if a struct path is a mountpoint for this case. Link: http://lkml.kernel.org/r/20161011053358.27645.9729.stgit@pluto.themaw.netSigned-off-by: NIan Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Omar Sandoval <osandov@osandov.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 11 10月, 2016 1 次提交
-
-
由 Emese Revfy 提交于
The __latent_entropy gcc attribute can be used only on functions and variables. If it is on a function then the plugin will instrument it for gathering control-flow entropy. If the attribute is on a variable then the plugin will initialize it with random contents. The variable must be an integer, an integer array type or a structure with integer fields. These specific functions have been selected because they are init functions (to help gather boot-time entropy), are called at unpredictable times, or they have variable loops, each of which provide some level of latent entropy. Signed-off-by: NEmese Revfy <re.emese@gmail.com> [kees: expanded commit message] Signed-off-by: NKees Cook <keescook@chromium.org>
-
- 01 10月, 2016 1 次提交
-
-
由 Eric W. Biederman 提交于
CAI Qian <caiqian@redhat.com> pointed out that the semantics of shared subtrees make it possible to create an exponentially increasing number of mounts in a mount namespace. mkdir /tmp/1 /tmp/2 mount --make-rshared / for i in $(seq 1 20) ; do mount --bind /tmp/1 /tmp/2 ; done Will create create 2^20 or 1048576 mounts, which is a practical problem as some people have managed to hit this by accident. As such CVE-2016-6213 was assigned. Ian Kent <raven@themaw.net> described the situation for autofs users as follows: > The number of mounts for direct mount maps is usually not very large because of > the way they are implemented, large direct mount maps can have performance > problems. There can be anywhere from a few (likely case a few hundred) to less > than 10000, plus mounts that have been triggered and not yet expired. > > Indirect mounts have one autofs mount at the root plus the number of mounts that > have been triggered and not yet expired. > > The number of autofs indirect map entries can range from a few to the common > case of several thousand and in rare cases up to between 30000 and 50000. I've > not heard of people with maps larger than 50000 entries. > > The larger the number of map entries the greater the possibility for a large > number of active mounts so it's not hard to expect cases of a 1000 or somewhat > more active mounts. So I am setting the default number of mounts allowed per mount namespace at 100,000. This is more than enough for any use case I know of, but small enough to quickly stop an exponential increase in mounts. Which should be perfect to catch misconfigurations and malfunctioning programs. For anyone who needs a higher limit this can be changed by writing to the new /proc/sys/fs/mount-max sysctl. Tested-by: NCAI Qian <caiqian@redhat.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 23 9月, 2016 2 次提交
-
-
由 Andrey Vagin 提交于
Return -EPERM if an owning user namespace is outside of a process current user namespace. v2: In a first version ns_get_owner returned ENOENT for init_user_ns. This special cases was removed from this version. There is nothing outside of init_user_ns, so we can return EPERM. v3: rename ns->get_owner() to ns->owner(). get_* usually means that it grabs a reference. Acked-by: NSerge Hallyn <serge@hallyn.com> Signed-off-by: NAndrei Vagin <avagin@openvz.org> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
The current error codes returned when a the per user per user namespace limit are hit (EINVAL, EUSERS, and ENFILE) are wrong. I asked for advice on linux-api and it we made clear that those were the wrong error code, but a correct effor code was not suggested. The best general error code I have found for hitting a resource limit is ENOSPC. It is not perfect but as it is unambiguous it will serve until someone comes up with a better error code. Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 16 9月, 2016 1 次提交
-
-
由 Miklos Szeredi 提交于
This patch allows flock, posix locks, ofd locks and leases to work correctly on overlayfs. Instead of using the underlying inode for storing lock context use the overlay inode. This allows locks to be persistent across copy-up. This is done by introducing locks_inode() helper and using it instead of file_inode() to get the inode in locking code. For non-overlayfs the two are equivalent, except for an extra pointer dereference in locks_inode(). Since lock operations are in "struct file_operations" we must also make sure not to call underlying filesystem's lock operations. Introcude a super block flag MS_NOREMOTELOCK to this effect. Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com> Acked-by: NJeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org>
-
- 31 8月, 2016 1 次提交
-
-
由 Eric W. Biederman 提交于
v2: Fixed the very obvious lack of setting ucounts on struct mnt_ns reported by Andrei Vagin, and the kbuild test report. Reported-by: NAndrei Vagin <avagin@openvz.org> Acked-by: NKees Cook <keescook@chromium.org> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 01 7月, 2016 1 次提交
-
-
由 Andrey Ulanov 提交于
- m_start() in fs/namespace.c expects that ns->event is incremented each time a mount added or removed from ns->list. - umount_tree() removes items from the list but does not increment event counter, expecting that it's done before the function is called. - There are some codepaths that call umount_tree() without updating "event" counter. e.g. from __detach_mounts(). - When this happens m_start may reuse a cached mount structure that no longer belongs to ns->list (i.e. use after free which usually leads to infinite loop). This change fixes the above problem by incrementing global event counter before invoking umount_tree(). Change-Id: I622c8e84dcb9fb63542372c5dbf0178ee86bb589 Cc: stable@vger.kernel.org Signed-off-by: NAndrey Ulanov <andreyu@google.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 24 6月, 2016 5 次提交
-
-
由 Andy Lutomirski 提交于
If a process gets access to a mount from a different user namespace, that process should not be able to take advantage of setuid files or selinux entrypoints from that filesystem. Prevent this by treating mounts from other mount namespaces and those not owned by current_user_ns() or an ancestor as nosuid. This will make it safer to allow more complex filesystems to be mounted in non-root user namespaces. This does not remove the need for MNT_LOCK_NOSUID. The setuid, setgid, and file capability bits can no longer be abused if code in a user namespace were to clear nosuid on an untrusted filesystem, but this patch, by itself, is insufficient to protect the system from abuse of files that, when execed, would increase MAC privilege. As a more concrete explanation, any task that can manipulate a vfsmount associated with a given user namespace already has capabilities in that namespace and all of its descendents. If they can cause a malicious setuid, setgid, or file-caps executable to appear in that mount, then that executable will only allow them to elevate privileges in exactly the set of namespaces in which they are already privileges. On the other hand, if they can cause a malicious executable to appear with a dangerous MAC label, running it could change the caller's security context in a way that should not have been possible, even inside the namespace in which the task is confined. As a hardening measure, this would have made CVE-2014-5207 much more difficult to exploit. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Signed-off-by: NSeth Forshee <seth.forshee@canonical.com> Acked-by: NJames Morris <james.l.morris@oracle.com> Acked-by: NSerge Hallyn <serge.hallyn@canonical.com> Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
Replace the implict setting of MNT_NODEV on mounts that happen with just user namespace permissions with an implicit setting of SB_I_NODEV in s_iflags. The visibility of the implicit MNT_NODEV has caused problems in the past. With this change the fragile case where an implicit MNT_NODEV needs to be preserved in do_remount is removed. Using SB_I_NODEV is much less fragile as s_iflags are set during the original mount and never changed. In do_new_mount with the implicit setting of MNT_NODEV gone, the only code that can affect mnt_flags is fs_fully_visible so simplify the if statement and reduce the indentation of the code to make that clear. Acked-by: NSeth Forshee <seth.forshee@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
Verify all filesystems that we check in mount_too_revealing set SB_I_NOEXEC and SB_I_NODEV in sb->s_iflags. That is true for today and it should remain true in the future. Remove the now unnecessary checks from mnt_already_visibile that ensure MNT_LOCK_NOSUID, MNT_LOCK_NOEXEC, and MNT_LOCK_NODEV are preserved. Making the code shorter and easier to read. Relying on SB_I_NOEXEC and SB_I_NODEV instead of the user visible MNT_NOSUID, MNT_NOEXEC, and MNT_NODEV ensures the many current systems where proc and sysfs are mounted with "nosuid, nodev, noexec" and several slightly buggy container applications don't bother to set those flags continue to work. Acked-by: NSeth Forshee <seth.forshee@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
Allowing a filesystem to be mounted by other than root in the initial user namespace is a filesystem property not a mount namespace property and as such should be checked in filesystem specific code. Move the FS_USERNS_MOUNT test into super.c:sget_userns(). Acked-by: NSeth Forshee <seth.forshee@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
Replace the call of fs_fully_visible in do_new_mount from before the new superblock is allocated with a call of mount_too_revealing after the superblock is allocated. This winds up being a much better location for maintainability of the code. The first change this enables is the replacement of FS_USERNS_VISIBLE with SB_I_USERNS_VISIBLE. Moving the flag from struct filesystem_type to sb_iflags on the superblock. Unfortunately mount_too_revealing fundamentally needs to touch mnt_flags adding several MNT_LOCKED_XXX flags at the appropriate times. If the mnt_flags did not need to be touched the code could be easily moved into the filesystem specific mount code. Acked-by: NSeth Forshee <seth.forshee@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 15 6月, 2016 1 次提交
-
-
由 Eric W. Biederman 提交于
In rare cases it is possible for s_flags & MS_RDONLY to be set but MNT_READONLY to be clear. This starting combination can cause fs_fully_visible to fail to ensure that the new mount is readonly. Therefore force MNT_LOCK_READONLY in the new mount if MS_RDONLY is set on the source filesystem of the mount. In general both MS_RDONLY and MNT_READONLY are set at the same for mounts so I don't expect any programs to care. Nor do I expect MS_RDONLY to be set on proc or sysfs in the initial user namespace, which further decreases the likelyhood of problems. Which means this change should only affect system configurations by paranoid sysadmins who should welcome the additional protection as it keeps people from wriggling out of their policies. Cc: stable@vger.kernel.org Fixes: 8c6cf9cc ("mnt: Modify fs_fully_visible to deal with locked ro nodev and atime") Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 07 6月, 2016 2 次提交
-
-
由 Eric W. Biederman 提交于
MNT_LOCKED implies on a child mount implies the child is locked to the parent. So while looping through the children the children should be tested (not their parent). Typically an unshare of a mount namespace locks all mounts together making both the parent and the slave as locked but there are a few corner cases where other things work. Cc: stable@vger.kernel.org Fixes: ceeb0e5d ("vfs: Ignore unlocked mounts in fs_fully_visible") Reported-by: NSeth Forshee <seth.forshee@canonical.com> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
由 Eric W. Biederman 提交于
Add this trivial missing error handling. Cc: stable@vger.kernel.org Fixes: 1b852bce ("mnt: Refactor the logic for mounting sysfs and proc in a user namespace") Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 23 1月, 2016 1 次提交
-
-
由 Al Viro 提交于
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: NAl Viro <viro@zeniv.linux.org.uk>
-
- 04 1月, 2016 1 次提交
-
-
由 Al Viro 提交于
let it just return NULL, pointer to kernel copy or ERR_PTR(). Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 07 12月, 2015 1 次提交
-
-
由 Yaowei Bai 提交于
This patch makes path_is_under return bool to improve readability due to this particular function only using either one or zero as its return value. No functional change. Signed-off-by: NYaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
-
- 16 11月, 2015 2 次提交
-
-
由 Eric W. Biederman 提交于
Since no one uses mandatory locking and files with mandatory locks can cause problems don't allow them in user namespaces. Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
-
由 Jeff Layton 提交于
Mandatory locking appears to be almost unused and buggy and there appears no real interest in doing anything with it. Since effectively no one uses the code and since the code is buggy let's allow it to be disabled at compile time. I would just suggest removing the code but undoubtedly that will break some piece of userspace code somewhere. For the distributions that don't care about this piece of code this gives a nice starting point to make mandatory locking go away. Cc: Benjamin Coddington <bcodding@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jeff Layton <jeff.layton@primarydata.com> Cc: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
-
- 24 7月, 2015 1 次提交
-
-
由 Eric W. Biederman 提交于
The handling of in detach_mounts of unmounted but connected mounts is buggy and can lead to an infinite loop. Correct the handling of unmounted mounts in detach_mount. When the mountpoint of an unmounted but connected mount is connected to a dentry, and that dentry is deleted we need to disconnect that mount from the parent mount and the deleted dentry. Nothing changes for the unmounted and connected children. They can be safely ignored. Cc: stable@vger.kernel.org Fixes: ce07d891 mnt: Honor MNT_LOCKED when detaching mounts Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-
- 23 7月, 2015 1 次提交
-
-
由 Eric W. Biederman 提交于
rmdir mntpoint will result in an infinite loop when there is a mount locked on the mountpoint in another mount namespace. This is because the logic to test to see if a mount should be disconnected in umount_tree is buggy. Move the logic to decide if a mount should remain connected to it's mountpoint into it's own function disconnect_mount so that clarity of expression instead of terseness of expression becomes a virtue. When the conditions where it is invalid to leave a mount connected are first ruled out, the logic for deciding if a mount should be disconnected becomes much clearer and simpler. Fixes: e0c9c0af mnt: Update detach_mounts to leave mounts connected Fixes: ce07d891 mnt: Honor MNT_LOCKED when detaching mounts Cc: stable@vger.kernel.org Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
-