kernel/linux.git/fs/proc, branch v3.8.7

userns: Restrict when proc and sysfs can be mounted

2013-04-05T16:26:02+00:00

commit 87a8ebd637dafc255070f503909a053cf0d98d3f upstream. Only allow unprivileged mounts of proc and sysfs if they are already mounted when the user namespace is created. proc and sysfs are interesting because they have content that is per namespace, and so fresh mounts are needed when new namespaces are created while at the same time proc and sysfs have content that is shared between every instance. Respect the policy of who may see the shared content of proc and sysfs by only allowing new mounts if there was an existing mount at the time the user namespace was created. In practice there are only two interesting cases: proc and sysfs are mounted at their usual places, proc and sysfs are not mounted at all (some form of mount namespace jail). Acked-by: Serge Hallyn Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman

vfs,proc: guarantee unique inodes in /proc

2013-03-28T19:17:32+00:00

commit 51f0885e5415b4cc6535e9cdcc5145bfbc134353 upstream. Dave Jones found another /proc issue with his Trinity tool: thanks to the namespace model, we can have multiple /proc dentries that point to the same inode, aliasing directories in /proc//net/ for example. This ends up being a total disaster, because it acts like hardlinked directories, and causes locking problems. We rely on the topological sort of the inodes pointed to by dentries, and if we have aliased directories, that odering becomes unreliable. In short: don't do this. Multiple dentries with the same (directory) inode is just a bad idea, and the namespace code should never have exposed things this way. But we're kind of stuck with it. This solves things by just always allocating a new inode during /proc dentry lookup, instead of using "iget_locked()" to look up existing inodes by superblock and number. That actually simplies the code a bit, at the cost of potentially doing more inode [de]allocations. That said, the inode lookup wasn't free either (and did a lot of locking of inodes), so it is probably not that noticeable. We could easily keep the old lookup model for non-directory entries, but rather than try to be excessively clever this just implements the minimal and simplest workaround for the problem. Reported-and-tested-by: Dave Jones Analyzed-by: Al Viro Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

saner proc_get_inode() calling conventions

2013-03-28T19:17:32+00:00

commit d3d009cb965eae7e002ea5badf603ea8f4c34915 upstream. Make it drop the pde in *all* cases when no new reference to it is put into an inode - both when an inode had already been set up (as we were already doing) and when inode allocation has failed. Makes for simpler logics in callers... Signed-off-by: Al Viro Cc: Linus Torvalds Cc: Dave Jones Signed-off-by: Greg Kroah-Hartman

proc: Use nd_jump_link in proc_ns_follow_link

2013-03-14T18:26:25+00:00

commit db04dc679bcc780ad6907943afe24a30de974a1b upstream. Update proc_ns_follow_link to use nd_jump_link instead of just manually updating nd.path.dentry. This fixes the BUG_ON(nd->inode != parent->d_inode) reported by Dave Jones and reproduced trivially with mkdir /proc/self/ns/uts/a. Sigh it looks like the VFS change to require use of nd_jump_link happend while proc_ns_follow_link was baking and since the common case of proc_ns_follow_link continued to work without problems the need for making this change was overlooked. Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman

mempolicy: remove arg from mpol_parse_str, mpol_to_str

2013-01-02T17:27:10+00:00

Remove the unused argument (formerly no_context) from mpol_parse_str() and from mpol_to_str(). Signed-off-by: Hugh Dickins Signed-off-by: Linus Torvalds

proc: Allow proc_free_inum to be called from any context

2012-12-26T00:23:12+00:00

While testing the pid namespace code I hit this nasty warning. [ 176.262617] ------------[ cut here ]------------ [ 176.263388] WARNING: at /home/eric/projects/linux/linux-userns-devel/kernel/softirq.c:160 local_bh_enable_ip+0x7a/0xa0() [ 176.265145] Hardware name: Bochs [ 176.265677] Modules linked in: [ 176.266341] Pid: 742, comm: bash Not tainted 3.7.0userns+ #18 [ 176.266564] Call Trace: [ 176.266564] [] warn_slowpath_common+0x7f/0xc0 [ 176.266564] [] warn_slowpath_null+0x1a/0x20 [ 176.266564] [] local_bh_enable_ip+0x7a/0xa0 [ 176.266564] [] _raw_spin_unlock_bh+0x19/0x20 [ 176.266564] [] proc_free_inum+0x3a/0x50 [ 176.266564] [] free_pid_ns+0x1c/0x80 [ 176.266564] [] put_pid_ns+0x35/0x50 [ 176.266564] [] put_pid+0x4a/0x60 [ 176.266564] [] tty_ioctl+0x717/0xc10 [ 176.266564] [] ? wait_consider_task+0x855/0xb90 [ 176.266564] [] ? default_spin_lock_flags+0x9/0x10 [ 176.266564] [] ? remove_wait_queue+0x5a/0x70 [ 176.266564] [] do_vfs_ioctl+0x98/0x550 [ 176.266564] [] ? recalc_sigpending+0x1f/0x60 [ 176.266564] [] ? __set_task_blocked+0x37/0x80 [ 176.266564] [] ? sys_wait4+0xab/0xf0 [ 176.266564] [] sys_ioctl+0x91/0xb0 [ 176.266564] [] ? task_stopped_code+0x50/0x50 [ 176.266564] [] system_call_fastpath+0x16/0x1b [ 176.266564] ---[ end trace 387af88219ad6143 ]--- It turns out that spin_unlock_bh(proc_inum_lock) is not safe when put_pid is called with another spinlock held and irqs disabled. For now take the easy path and use spin_lock_irqsave(proc_inum_lock) in proc_free_inum and spin_loc_irq in proc_alloc_inum(proc_inum_lock). Signed-off-by: "Eric W. Biederman"

Merge branch 'akpm' (Andrew's patch-bomb)

2012-12-21T04:00:43+00:00

Merge the rest of Andrew's patches for -rc1: "A bunch of fixes and misc missed-out-on things. That'll do for -rc1. I still have a batch of IPC patches which still have a possible bug report which I'm chasing down." * emailed patches from Andrew Morton : (25 commits) keys: use keyring_alloc() to create module signing keyring keys: fix unreachable code sendfile: allows bypassing of notifier events SGI-XP: handle non-fatal traps fat: fix incorrect function comment Documentation: ABI: remove testing/sysfs-devices-node proc: fix inconsistent lock state linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors memcg: don't register hotcpu notifier from ->css_alloc() checkpatch: warn on uapi #includes that #include mm: cma: WARN if freed memory is still in use exec: do not leave bprm->interp on stack ...

proc: fix inconsistent lock state

2012-12-21T01:40:20+00:00

Lockdep found an inconsistent lock state when rcu is processing delayed work in softirq. Currently, kernel is using spin_lock/spin_unlock to protect proc_inum_ida, but proc_free_inum is called by rcu in softirq context. Use spin_lock_bh/spin_unlock_bh fix following lockdep warning. ================================= [ INFO: inconsistent lock state ] 3.7.0 #36 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (proc_inum_lock){+.?...}, at: proc_free_inum+0x1c/0x50 {SOFTIRQ-ON-W} state was registered at: __lock_acquire+0x8ae/0xca0 lock_acquire+0x199/0x200 _raw_spin_lock+0x41/0x50 proc_alloc_inum+0x4c/0xd0 alloc_mnt_ns+0x49/0xc0 create_mnt_ns+0x25/0x70 mnt_init+0x161/0x1c7 vfs_caches_init+0x107/0x11a start_kernel+0x348/0x38c x86_64_start_reservations+0x131/0x136 x86_64_start_kernel+0x103/0x112 irq event stamp: 2993422 hardirqs last enabled at (2993422): _raw_spin_unlock_irqrestore+0x55/0x80 hardirqs last disabled at (2993421): _raw_spin_lock_irqsave+0x29/0x70 softirqs last enabled at (2993394): _local_bh_enable+0x13/0x20 softirqs last disabled at (2993395): call_softirq+0x1c/0x30 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(proc_inum_lock); lock(proc_inum_lock); *** DEADLOCK *** no locks held by swapper/1/0. stack backtrace: Pid: 0, comm: swapper/1 Not tainted 3.7.0 #36 Call Trace: [] ? vprintk_emit+0x471/0x510 print_usage_bug+0x2a5/0x2c0 mark_lock+0x33b/0x5e0 __lock_acquire+0x813/0xca0 lock_acquire+0x199/0x200 _raw_spin_lock+0x41/0x50 proc_free_inum+0x1c/0x50 free_pid_ns+0x1c/0x50 put_pid_ns+0x2e/0x50 put_pid+0x4a/0x60 delayed_put_pid+0x12/0x20 rcu_process_callbacks+0x462/0x790 __do_softirq+0x1b4/0x3b0 call_softirq+0x1c/0x30 do_softirq+0x59/0xd0 irq_exit+0x54/0xd0 smp_apic_timer_interrupt+0x95/0xa3 apic_timer_interrupt+0x72/0x80 cpuidle_enter_tk+0x10/0x20 cpuidle_enter_state+0x17/0x50 cpuidle_idle_call+0x287/0x520 cpu_idle+0xba/0x130 start_secondary+0x2b3/0x2bc Signed-off-by: Xiaotian Feng Cc: Al Viro Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: drop vmtruncate

2012-12-20T19:00:01+00:00

Removed vmtruncate Signed-off-by: Marco Stornelli Signed-off-by: Al Viro

Merge branch 'akpm' (Andrew's patch-bomb)

2012-12-18T04:58:12+00:00

Merge misc patches from Andrew Morton: "Incoming: - lots of misc stuff - backlight tree updates - lib/ updates - Oleg's percpu-rwsem changes - checkpatch - rtc - aoe - more checkpoint/restart support I still have a pile of MM stuff pending - Pekka should be merging later today after which that is good to go. A number of other things are twiddling thumbs awaiting maintainer merges." * emailed patches from Andrew Morton : (180 commits) scatterlist: don't BUG when we can trivially return a proper error. docs: update documentation about /proc//fdinfo/ fanotify output fs, fanotify: add @mflags field to fanotify output docs: add documentation about /proc//fdinfo/ output fs, notify: add procfs fdinfo helper fs, exportfs: add exportfs_encode_inode_fh() helper fs, exportfs: escape nil dereference if no s_export_op present fs, epoll: add procfs fdinfo helper fs, eventfd: add procfs fdinfo helper procfs: add ability to plug in auxiliary fdinfo providers tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test breakpoint selftests: print failure status instead of cause make error kcmp selftests: print fail status instead of cause make error kcmp selftests: make run_tests fix mem-hotplug selftests: print failure status instead of cause make error cpu-hotplug selftests: print failure status instead of cause make error mqueue selftests: print failure status instead of cause make error vm selftests: print failure status instead of cause make error ubifs: use prandom_bytes mtd: nandsim: use prandom_bytes ...