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2018-03-24Revert "mqueue: switch to on-demand creation of internal mount"Eric W. Biederman
This reverts commit 36735a6a2b5e042db1af956ce4bcc13f3ff99e21. Aleksa Sarai <asarai@suse.de> writes: > [REGRESSION v4.16-rc6] [PATCH] mqueue: forbid unprivileged user access to internal mount > > Felix reported weird behaviour on 4.16.0-rc6 with regards to mqueue[1], > which was introduced by 36735a6a2b5e ("mqueue: switch to on-demand > creation of internal mount"). > > Basically, the reproducer boils down to being able to mount mqueue if > you create a new user namespace, even if you don't unshare the IPC > namespace. > > Previously this was not possible, and you would get an -EPERM. The mount > is the *host* mqueue mount, which is being cached and just returned from > mqueue_mount(). To be honest, I'm not sure if this is safe or not (or if > it was intentional -- since I'm not familiar with mqueue). > > To me it looks like there is a missing permission check. I've included a > patch below that I've compile-tested, and should block the above case. > Can someone please tell me if I'm missing something? Is this actually > safe? > > [1]: https://github.com/docker/docker/issues/36674 The issue is a lot deeper than a missing permission check. sb->s_user_ns was is improperly set as well. So in addition to the filesystem being mounted when it should not be mounted, so things are not allow that should be. We are practically to the release of 4.16 and there is no agreement between Al Viro and myself on what the code should looks like to fix things properly. So revert the code to what it was before so that we can take our time and discuss this properly. Fixes: 36735a6a2b5e ("mqueue: switch to on-demand creation of internal mount") Reported-by: Felix Abecassis <fabecassis@nvidia.com> Reported-by: Aleksa Sarai <asarai@suse.de> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06ipc/mqueue.c: have RT tasks queue in by priority in wq_add()Jonathan Haws
Previous behavior added tasks to the work queue using the static_prio value instead of the dynamic priority value in prio. This caused RT tasks to be added to the work queue in a FIFO manner rather than by priority. Normal tasks were handled by priority. This fix utilizes the dynamic priority of the task to ensure that both RT and normal tasks are added to the work queue in priority order. Utilizing the dynamic priority (prio) rather than the base priority (normal_prio) was chosen to ensure that if a task had a boosted priority when it was added to the work queue, it would be woken sooner to to ensure that it releases any other locks it may be holding in a more timely manner. It is understood that the task could have a lower priority when it wakes than when it was added to the queue in this (unlikely) case. Link: http://lkml.kernel.org/r/1513006652-7014-1-git-send-email-jhaws@sdl.usu.edu Signed-off-by: Jonathan Haws <jhaws@sdl.usu.edu> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-30Merge branch 'work.mqueue' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mqueue/bpf vfs cleanups from Al Viro: "mqueue and bpf go through rather painful and similar contortions to create objects in their dentry trees. Provide a primitive for doing that without abusing ->mknod(), switch bpf and mqueue to it. Another mqueue-related thing that has ended up in that branch is on-demand creation of internal mount (based upon the work of Giuseppe Scrivano)" * 'work.mqueue' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mqueue: switch to on-demand creation of internal mount tidy do_mq_open() up a bit mqueue: clean prepare_open() up do_mq_open(): move all work prior to dentry_open() into a helper mqueue: fold mq_attr_ok() into mqueue_get_inode() move dentry_open() calls up into do_mq_open() mqueue: switch to vfs_mkobj(), quit abusing ->d_fsdata bpf_obj_do_pin(): switch to vfs_mkobj(), quit abusing ->mknod() new primitive: vfs_mkobj()
2018-01-30Merge branch 'misc.poll' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
2018-01-12signal: Ensure generic siginfos the kernel sends have all bits initializedEric W. Biederman
Call clear_siginfo to ensure stack allocated siginfos are fully initialized before being passed to the signal sending functions. This ensures that if there is the kind of confusion documented by TRAP_FIXME, FPE_FIXME, or BUS_FIXME the kernel won't send unitialized data to userspace when the kernel generates a signal with SI_USER but the copy to userspace assumes it is a different kind of signal, and different fields are initialized. This also prepares the way for turning copy_siginfo_to_user into a copy_to_user, by removing the need in many cases to perform a field by field copy simply to skip the uninitialized fields. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-01-05mqueue: switch to on-demand creation of internal mountAl Viro
Instead of doing that upon each ipcns creation, we do that the first time mq_open(2) or mqueue mount is done in an ipcns. What's more, doing that allows to get rid of mount_ns() use - we can go with considerably cheaper mount_nodev(), avoiding the loop over all mqueue superblock instances; ipcns->mq_mnt is used to locate preexisting instance in O(1) time instead of O(instances) mount_ns() would've cost us. Based upon the version by Giuseppe Scrivano <gscrivan@redhat.com>; I've added handling of userland mqueue mounts (original had been broken in that area) and added a switch to mount_nodev(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05tidy do_mq_open() up a bitAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05mqueue: clean prepare_open() upAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05do_mq_open(): move all work prior to dentry_open() into a helperAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05mqueue: fold mq_attr_ok() into mqueue_get_inode()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05move dentry_open() calls up into do_mq_open()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-01-05mqueue: switch to vfs_mkobj(), quit abusing ->d_fsdataAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27ipc, kernel, mm: annotate ->poll() instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-27Rename superblock flags (MS_xyz -> SB_xyz)Linus Torvalds
This is a pure automated search-and-replace of the internal kernel superblock flags. The s_flags are now called SB_*, with the names and the values for the moment mirroring the MS_* flags that they're equivalent to. Note how the MS_xyz flags are the ones passed to the mount system call, while the SB_xyz flags are what we then use in sb->s_flags. The script to do this was: # places to look in; re security/*: it generally should *not* be # touched (that stuff parses mount(2) arguments directly), but # there are two places where we really deal with superblock flags. FILES="drivers/mtd drivers/staging/lustre fs ipc mm \ include/linux/fs.h include/uapi/linux/bfs_fs.h \ security/apparmor/apparmorfs.c security/apparmor/include/lib.h" # the list of MS_... constants SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \ DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \ POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \ I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \ ACTIVE NOUSER" SED_PROG= for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done # we want files that contain at least one of MS_..., # with fs/namespace.c and fs/pnode.c excluded. L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c') for f in $L; do sed -i $f $SED_PROG; done Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-03ipc: mqueue: Replace timespec with timespec64Deepa Dinamani
struct timespec is not y2038 safe. Replace all uses of timespec by y2038 safe struct timespec64. Even though timespec is used here to represent timeouts, replace these with timespec64 so that it facilitates in verification by creating a y2038 safe kernel image that is free of timespec. The syscall interfaces themselves are not changed as part of the patch. They will be part of a different series. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Richard Guy Briggs <rgb@redhat.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-09mqueue: fix a use-after-free in sys_mq_notify()Cong Wang
The retry logic for netlink_attachskb() inside sys_mq_notify() is nasty and vulnerable: 1) The sock refcnt is already released when retry is needed 2) The fd is controllable by user-space because we already release the file refcnt so we when retry but the fd has been just closed by user-space during this small window, we end up calling netlink_detachskb() on the error path which releases the sock again, later when the user-space closes this socket a use-after-free could be triggered. Setting 'sock' to NULL here should be sufficient to fix it. Reported-by: GeneBlue <geneblue.mail@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-04mqueue: move compat syscalls to native onesAl Viro
... and stop messing with compat_alloc_user_space() and friends [braino fix from Colin King folded in] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/user.h> We are going to split <linux/sched/user.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/user.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus 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: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/signal.h> We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/signal.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus 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: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar
<linux/sched/wake_q.h> We are going to split <linux/sched/wake_q.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/wake_q.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-27ipc/mqueue: add missing sparse annotationLuc Van Oostenryck
Link: http://lkml.kernel.org/r/20170128235704.45302-1-luc.vanoostenryck@gmail.com Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-21sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_QWaiman Long
Currently the wake_q data structure is defined by the WAKE_Q() macro. This macro, however, looks like a function doing something as "wake" is a verb. Even checkpatch.pl was confused as it reported warnings like WARNING: Missing a blank line after declarations #548: FILE: kernel/futex.c:3665: + int ret; + WAKE_Q(wake_q); This patch renames the WAKE_Q() macro to DEFINE_WAKE_Q() which clarifies what the macro is doing and eliminates the checkpatch.pl warnings. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1479401198-1765-1-git-send-email-longman@redhat.com [ Resolved conflict and added missing rename. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-27fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-23vfs: Generalize filesystem nodev handling.Eric W. Biederman
Introduce a function may_open_dev that tests MNT_NODEV and a new superblock flab SB_I_NODEV. Use this new function in all of the places where MNT_NODEV was previously tested. Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those filesystems should never support device nodes, and a simple superblock flags makes that very hard to get wrong. With SB_I_NODEV set if any device nodes somehow manage to show up on on a filesystem those device nodes will be unopenable. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-23ipc/mqueue: The mqueue filesystem should never contain executablesEric W. Biederman
Set SB_I_NOEXEC on mqueuefs to ensure small implementation mistakes do not result in executable on mqueuefs by accident. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-23vfs: Pass data, ns, and ns->userns to mount_nsEric W. Biederman
Today what is normally called data (the mount options) is not passed to fill_super through mount_ns. Pass the mount options and the namespace separately to mount_ns so that filesystems such as proc that have mount options, can use mount_ns. Pass the user namespace to mount_ns so that the standard permission check that verifies the mounter has permissions over the namespace can be performed in mount_ns instead of in each filesystems .mount method. Thus removing the duplication between mqueuefs and proc in terms of permission checks. The extra permission check does not currently affect the rpc_pipefs filesystem and the nfsd filesystem as those filesystems do not currently allow unprivileged mounts. Without unpvileged mounts it is guaranteed that the caller has already passed capable(CAP_SYS_ADMIN) which guarantees extra permission check will pass. Update rpc_pipefs and the nfsd filesystem to ensure that the network namespace reference is always taken in fill_super and always put in kill_sb so that the logic is simpler and so that errors originating inside of fill_super do not cause a network namespace leak. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-22wrappers for ->i_mutex accessAl Viro
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 <viro@zeniv.linux.org.uk>
2016-01-14kmemcg: account certain kmem allocations to memcgVladimir Davydov
Mark those kmem allocations that are known to be easily triggered from userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to memcg. For the list, see below: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This is the most tedious part, because most filesystems overwrite the alloc_inode method. The list is far from complete, so feel free to add more objects. Nevertheless, it should be close to "account everything" approach and keep most workloads within bounds. Malevolent users will be able to breach the limit, but this was possible even with the former "account everything" approach (simply because it did not account everything in fact). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07ipc: modify message queue accounting to not take kernel data structures into ↵Marcus Gelderie
account A while back, the message queue implementation in the kernel was improved to use btrees to speed up retrieval of messages, in commit d6629859b36d ("ipc/mqueue: improve performance of send/recv"). That patch introducing the improved kernel handling of message queues (using btrees) has, as a by-product, changed the meaning of the QSIZE field in the pseudo-file created for the queue. Before, this field reflected the size of the user-data in the queue. Since, it also takes kernel data structures into account. For example, if 13 bytes of user data are in the queue, on my machine the file reports a size of 61 bytes. There was some discussion on this topic before (for example https://lkml.org/lkml/2014/10/1/115). Commenting on a th lkml, Michael Kerrisk gave the following background (https://lkml.org/lkml/2015/6/16/74): The pseudofiles in the mqueue filesystem (usually mounted at /dev/mqueue) expose fields with metadata describing a message queue. One of these fields, QSIZE, as originally implemented, showed the total number of bytes of user data in all messages in the message queue, and this feature was documented from the beginning in the mq_overview(7) page. In 3.5, some other (useful) work happened to break the user-space API in a couple of places, including the value exposed via QSIZE, which now includes a measure of kernel overhead bytes for the queue, a figure that renders QSIZE useless for its original purpose, since there's no way to deduce the number of overhead bytes consumed by the implementation. (The other user-space breakage was subsequently fixed.) This patch removes the accounting of kernel data structures in the queue. Reporting the size of these data-structures in the QSIZE field was a breaking change (see Michael's comment above). Without the QSIZE field reporting the total size of user-data in the queue, there is no way to deduce this number. It should be noted that the resource limit RLIMIT_MSGQUEUE is counted against the worst-case size of the queue (in both the old and the new implementation). Therefore, the kernel overhead accounting in QSIZE is not necessary to help the user understand the limitations RLIMIT imposes on the processes. Signed-off-by: Marcus Gelderie <redmnic@gmail.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Cc: David Howells <dhowells@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: John Duffy <jb_duffy@btinternet.com> Cc: Arto Bendiken <arto@bendiken.net> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-08ipc/mqueue: Implement lockless pipelined wakeupsDavidlohr Bueso
This patch moves the wakeup_process() invocation so it is not done under the info->lock by making use of a lockless wake_q. With this change, the waiter is woken up once it is STATE_READY and it does not need to loop on SMP if it is still in STATE_PENDING. In the timeout case we still need to grab the info->lock to verify the state. This change should also avoid the introduction of preempt_disable() in -rt which avoids a busy-loop which pools for the STATE_PENDING -> STATE_READY change if the waiter has a higher priority compared to the waker. Additionally, this patch micro-optimizes wq_sleep by using the cheaper cousin of set_current_state(TASK_INTERRUPTABLE) as we will block no matter what, thus get rid of the implied barrier. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: George Spelvin <linux@horizon.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Mason <clm@fb.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: dave@stgolabs.net Link: http://lkml.kernel.org/r/1430748166.1940.17.camel@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-15VFS: assorted weird filesystems: d_inode() annotationsDavid Howells
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19new helper: audit_file()Al Viro
... 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 <viro@zeniv.linux.org.uk>
2014-04-07ipc: use device_initcallDavidlohr Bueso
... since __initcall is now deprecated. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-25ipc,mqueue: remove limits for the amount of system-wide queuesDavidlohr Bueso
Commit 93e6f119c0ce ("ipc/mqueue: cleanup definition names and locations") added global hardcoded limits to the amount of message queues that can be created. While these limits are per-namespace, reality is that it ends up breaking userspace applications. Historically users have, at least in theory, been able to create up to INT_MAX queues, and limiting it to just 1024 is way too low and dramatic for some workloads and use cases. For instance, Madars reports: "This update imposes bad limits on our multi-process application. As our app uses approaches that each process opens its own set of queues (usually something about 3-5 queues per process). In some scenarios we might run up to 3000 processes or more (which of-course for linux is not a problem). Thus we might need up to 9000 queues or more. All processes run under one user." Other affected users can be found in launchpad bug #1155695: https://bugs.launchpad.net/ubuntu/+source/manpages/+bug/1155695 Instead of increasing this limit, revert it entirely and fallback to the original way of dealing queue limits -- where once a user's resource limit is reached, and all memory is used, new queues cannot be created. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reported-by: Madars Vitolins <m@silodev.com> Acked-by: Doug Ledford <dledford@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27ipc: remove braces for single statementsDavidlohr Bueso
Deal with checkpatch messages: WARNING: braces {} are not necessary for single statement blocks Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-27ipc: whitespace cleanupManfred Spraul
The ipc code does not adhere the typical linux coding style. This patch fixes lots of simple whitespace errors. - mostly autogenerated by scripts/checkpatch.pl -f --fix \ --types=pointer_location,spacing,space_before_tab - one manual fixup (keep structure members tab-aligned) - removal of additional space_before_tab that were not found by --fix Tested with some of my msg and sem test apps. Andrew: Could you include it in -mm and move it towards Linus' tree? Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Suggested-by: Li Bin <huawei.libin@huawei.com> Cc: Joe Perches <joe@perches.com> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-09locks: break delegations on unlinkJ. Bruce Fields
We need to break delegations on any operation that changes the set of links pointing to an inode. Start with unlink. Such operations also hold the i_mutex on a parent directory. Breaking a delegation may require waiting for a timeout (by default 90 seconds) in the case of a unresponsive NFS client. To avoid blocking all directory operations, we therefore drop locks before waiting for the delegation. The logic then looks like: acquire locks ... test for delegation; if found: take reference on inode release locks wait for delegation break drop reference on inode retry It is possible this could never terminate. (Even if we take precautions to prevent another delegation being acquired on the same inode, we could get a different inode on each retry.) But this seems very unlikely. The initial test for a delegation happens after the lock on the target inode is acquired, but the directory inode may have been acquired further up the call stack. We therefore add a "struct inode **" argument to any intervening functions, which we use to pass the inode back up to the caller in the case it needs a delegation synchronously broken. Cc: David Howells <dhowells@redhat.com> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Dustin Kirkland <dustin.kirkland@gazzang.com> Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-09audit: fix mq_open and mq_unlink to add the MQ root as a hidden parent ↵Jeff Layton
audit_names record The old audit PATH records for mq_open looked like this: type=PATH msg=audit(1366282323.982:869): item=1 name=(null) inode=6777 dev=00:0c mode=041777 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:tmpfs_t:s15:c0.c1023 type=PATH msg=audit(1366282323.982:869): item=0 name="test_mq" inode=26732 dev=00:0c mode=0100700 ouid=0 ogid=0 rdev=00:00 obj=staff_u:object_r:user_tmpfs_t:s15:c0.c1023 ...with the audit related changes that went into 3.7, they now look like this: type=PATH msg=audit(1366282236.776:3606): item=2 name=(null) inode=66655 dev=00:0c mode=0100700 ouid=0 ogid=0 rdev=00:00 obj=staff_u:object_r:user_tmpfs_t:s15:c0.c1023 type=PATH msg=audit(1366282236.776:3606): item=1 name=(null) inode=6926 dev=00:0c mode=041777 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:tmpfs_t:s15:c0.c1023 type=PATH msg=audit(1366282236.776:3606): item=0 name="test_mq" Both of these look wrong to me. As Steve Grubb pointed out: "What we need is 1 PATH record that identifies the MQ. The other PATH records probably should not be there." Fix it to record the mq root as a parent, and flag it such that it should be hidden from view when the names are logged, since the root of the mq filesystem isn't terribly interesting. With this change, we get a single PATH record that looks more like this: type=PATH msg=audit(1368021604.836:484): item=0 name="test_mq" inode=16914 dev=00:0c mode=0100644 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmpfs_t:s0 In order to do this, a new audit_inode_parent_hidden() function is added. If we do it this way, then we avoid having the existing callers of audit_inode needing to do any sort of flag conversion if auditing is inactive. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reported-by: Jiri Jaburek <jjaburek@redhat.com> Cc: Steve Grubb <sgrubb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-28Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns fixes from Eric W Biederman: "The bulk of the changes are fixing the worst consequences of the user namespace design oversight in not considering what happens when one namespace starts off as a clone of another namespace, as happens with the mount namespace. The rest of the changes are just plain bug fixes. Many thanks to Andy Lutomirski for pointing out many of these issues." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Restrict when proc and sysfs can be mounted ipc: Restrict mounting the mqueue filesystem vfs: Carefully propogate mounts across user namespaces vfs: Add a mount flag to lock read only bind mounts userns: Don't allow creation if the user is chrooted yama: Better permission check for ptraceme pid: Handle the exit of a multi-threaded init. scm: Require CAP_SYS_ADMIN over the current pidns to spoof pids.
2013-03-27ipc: Restrict mounting the mqueue filesystemEric W. Biederman
Only allow mounting the mqueue filesystem if the caller has CAP_SYS_ADMIN rights over the ipc namespace. The principle here is if you create or have capabilities over it you can mount it, otherwise you get to live with what other people have mounted. This information is not particularly sensitive and mqueue essentially only reports which posix messages queues exist. Still when creating a restricted environment for an application to live any extra information may be of use to someone with sufficient creativity. The historical if imperfect way this information has been restricted has been not to allow mounts and restricting this to ipc namespace creators maintains the spirit of the historical restriction. Cc: stable@vger.kernel.org Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-22mqueue: sys_mq_open: do not call mnt_drop_write() if read-onlyVladimir Davydov
mnt_drop_write() must be called only if mnt_want_write() succeeded, otherwise the mnt_writers counter will diverge. mnt_writers counters are used to check if remounting FS as read-only is OK, so after an extra mnt_drop_write() call, it would be impossible to remount mqueue FS as read-only. Besides, on umount a warning would be printed like this one: ===================================== [ BUG: bad unlock balance detected! ] 3.9.0-rc3 #5 Not tainted ------------------------------------- a.out/12486 is trying to release lock (sb_writers) at: mnt_drop_write+0x1f/0x30 but there are no more locks to release! Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Doug Ledford <dledford@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-27userns: Allow the unprivileged users to mount mqueue fsGao feng
This patch allow the unprivileged user to mount mqueuefs in user ns. If two userns share the same ipcns,the files in mqueue fs should be seen in both these two userns. If the userns has its own ipcns,it has its own mqueue fs too. ipcns has already done this job well. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-10-12audit: make audit_inode take struct filenameJeff Layton
Keep a pointer to the audit_names "slot" in struct filename. Have all of the audit_inode callers pass a struct filename ponter to audit_inode instead of a string pointer. If the aname field is already populated, then we can skip walking the list altogether and just use it directly. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12vfs: define struct filename and have getname() return itJeff Layton
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: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12audit: set the name_len in audit_inode for parent lookupsJeff Layton
Currently, this gets set mostly by happenstance when we call into audit_inode_child. While that might be a little more efficient, it seems wrong. If the syscall ends up failing before audit_inode_child ever gets called, then you'll have an audit_names record that shows the full path but has the parent inode info attached. Fix this by passing in a parent flag when we call audit_inode that gets set to the value of LOOKUP_PARENT. We can then fix up the pathname for the audit entry correctly from the get-go. While we're at it, clean up the no-op macro for audit_inode in the !CONFIG_AUDITSYSCALL case. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-09ipc/mqueue: remove unnecessary rb_init_node() callsMichel Lespinasse
Commit d6629859b36d ("ipc/mqueue: improve performance of send/recv") and ce2d52cc ("ipc/mqueue: add rbtree node caching support") introduced an rbtree of message priorities, and usage of rb_init_node() to initialize the corresponding nodes. As it turns out, rb_init_node() is unnecessary here, as the nodes are fully initialized on insertion by rb_link_node() and the code doesn't access nodes that aren't inserted on the rbtree. Removing the rb_init_node() calls as I removed that function during rbtree API cleanups (the only other use of it was in a place that similarly didn't require it). Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>