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  1. 22 Aug, 2018 23 commits
  3. 12 Aug, 2018 4 commits
    • Linus Torvalds's avatar
      Linux 4.18 · 94710cac
      Linus Torvalds authored
      94710cac
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 921195d3
      Linus Torvalds authored 
      Pull SCSI fixes from James Bottomley:
 "Eight fixes.

  The most important one is the mpt3sas fix which makes the driver work
  again on big endian systems. The rest are mostly minor error path or
  checker issues and the vmw_scsi one fixes a performance problem"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: vmw_pvscsi: Return DID_RESET for status SAM_STAT_COMMAND_TERMINATED
  scsi: sr: Avoid that opening a CD-ROM hangs with runtime power management enabled
  scsi: mpt3sas: Swap I/O memory read value back to cpu endianness
  scsi: fcoe: clear FC_RP_STARTED flags when receiving a LOGO
  scsi: fcoe: drop frames in ELS LOGO error path
  scsi: fcoe: fix use-after-free in fcoe_ctlr_els_send
  scsi: qedi: Fix a potential buffer overflow
  scsi: qla2xxx: Fix memory leak for allocating abort IOCB
      921195d3
    • Linus Torvalds's avatar
      init: rename and re-order boot_cpu_state_init() · b5b1404d
      Linus Torvalds authored 
      This is purely a preparatory patch for upcoming changes during the 4.19
merge window.

We have a function called "boot_cpu_state_init()" that isn't really
about the bootup cpu state: that is done much earlier by the similarly
named "boot_cpu_init()" (note lack of "state" in name).

This function initializes some hotplug CPU state, and needs to run after
the percpu data has been properly initialized.  It even has a comment to
that effect.

Except it _doesn't_ actually run after the percpu data has been properly
initialized.  On x86 it happens to do that, but on at least arm and
arm64, the percpu base pointers are initialized by the arch-specific
'smp_prepare_boot_cpu()' hook, which ran _after_ boot_cpu_state_init().

This had some unexpected results, and in particular we have a patch
pending for the merge window that did the obvious cleanup of using
'this_cpu_write()' in the cpu hotplug init code:

  -       per_cpu_ptr(&cpuhp_state, smp_processor_id())->state = CPUHP_ONLINE;
  +       this_cpu_write(cpuhp_state.state, CPUHP_ONLINE);

which is obviously the right thing to do.  Except because of the
ordering issue, it actually failed miserably and unexpectedly on arm64.

So this just fixes the ordering, and changes the name of the function to
be 'boot_cpu_hotplug_init()' to make it obvious that it's about cpu
hotplug state, because the core CPU state was supposed to have already
been done earlier.

Marked for stable, since the (not yet merged) patch that will show this
problem is marked for stable.
Reported-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reported-by: default avatarMian Yousaf Kaukab <yousaf.kaukab@suse.com>
Suggested-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@kernel.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b5b1404d
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · d6dd6431
      Linus Torvalds authored 
      Pull vfs fixes from Al Viro:
 "A bunch of race fixes, mostly around lazy pathwalk.

  All of it is -stable fodder, a large part going back to 2013"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  make sure that __dentry_kill() always invalidates d_seq, unhashed or not
  fix __legitimize_mnt()/mntput() race
  fix mntput/mntput race
  root dentries need RCU-delayed freeing
      d6dd6431
  5. 11 Aug, 2018 9 commits
  7. 10 Aug, 2018 2 commits
  9. 09 Aug, 2018 2 commits
    • Al Viro's avatar
      make sure that __dentry_kill() always invalidates d_seq, unhashed or not · 4c0d7cd5
      Al Viro authored 
      RCU pathwalk relies upon the assumption that anything that changes
->d_inode of a dentry will invalidate its ->d_seq.  That's almost
true - the one exception is that the final dput() of already unhashed
dentry does *not* touch ->d_seq at all.  Unhashing does, though,
so for anything we'd found by RCU dcache lookup we are fine.
Unfortunately, we can *start* with an unhashed dentry or jump into
it.

We could try and be careful in the (few) places where that could
happen.  Or we could just make the final dput() invalidate the damn
thing, unhashed or not.  The latter is much simpler and easier to
backport, so let's do it that way.
Reported-by: default avatar"Dae R. Jeong" <threeearcat@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      4c0d7cd5
    • Al Viro's avatar
      fix __legitimize_mnt()/mntput() race · 119e1ef8
      Al Viro authored 
      __legitimize_mnt() has two problems - one is that in case of success
the check of mount_lock is not ordered wrt preceding increment of
refcount, making it possible to have successful __legitimize_mnt()
on one CPU just before the otherwise final mntpu() on another,
with __legitimize_mnt() not seeing mntput() taking the lock and
mntput() not seeing the increment done by __legitimize_mnt().
Solved by a pair of barriers.

Another is that failure of __legitimize_mnt() on the second
read_seqretry() leaves us with reference that'll need to be
dropped by caller; however, if that races with final mntput()
we can end up with caller dropping rcu_read_lock() and doing
mntput() to release that reference - with the first mntput()
having freed the damn thing just as rcu_read_lock() had been
dropped.  Solution: in "do mntput() yourself" failure case
grab mount_lock, check if MNT_DOOMED has been set by racing
final mntput() that has missed our increment and if it has -
undo the increment and treat that as "failure, caller doesn't
need to drop anything" case.

It's not easy to hit - the final mntput() has to come right
after the first read_seqretry() in __legitimize_mnt() *and*
manage to miss the increment done by __legitimize_mnt() before
the second read_seqretry() in there.  The things that are almost
impossible to hit on bare hardware are not impossible on SMP
KVM, though...
Reported-by: default avatarOleg Nesterov <oleg@redhat.com>
Fixes: 48a066e7 ("RCU'd vsfmounts")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      119e1ef8
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