linux-stable.git/fs, branch v4.19.26

afs: Fix key refcounting in file locking code

2019-02-27T09:08:56+00:00

[ Upstream commit 59d49076ae3e6912e6d7df2fd68e2337f3d02036 ]

Fix the refcounting of the authentication keys in the file locking code.
The vnode->lock_key member points to a key on which it expects to be
holding a ref, but it isn't always given an extra ref, however.

Fixes: 0fafdc9f888b ("afs: Fix file locking")
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

afs: Don't set vnode->cb_s_break in afs_validate()

2019-02-27T09:08:56+00:00

[ Upstream commit 4882a27cec24319d10f95e978ecc80050e3e3e15 ]

A cb_interest record is not necessarily attached to the vnode on entry to
afs_validate(), which can cause an oops when we try to bring the vnode's
cb_s_break up to date in the default case (ie. no current callback promise
and the vnode has not been deleted).

Fix this by simply removing the line, as vnode->cb_s_break will be set when
needed by afs_register_server_cb_interest() when we next get a callback
promise from RPC call.

The oops looks something like:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
    ...
    RIP: 0010:afs_validate+0x66/0x250 [kafs]
    ...
    Call Trace:
     afs_d_revalidate+0x8d/0x340 [kafs]
     ? __d_lookup+0x61/0x150
     lookup_dcache+0x44/0x70
     ? lookup_dcache+0x44/0x70
     __lookup_hash+0x24/0xa0
     do_unlinkat+0x11d/0x2c0
     __x64_sys_unlink+0x23/0x30
     do_syscall_64+0x4d/0xf0
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: ae3b7361dc0e ("afs: Fix validation/callback interaction")
Signed-off-by: Marc Dionne 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

proc, oom: do not report alien mms when setting oom_score_adj

2019-02-27T09:08:50+00:00

commit b2b469939e93458753cfbf8282ad52636495965e upstream.

Tetsuo has reported that creating a thousands of processes sharing MM
without SIGHAND (aka alien threads) and setting
/proc//oom_score_adj will swamp the kernel log and takes ages [1]
to finish.  This is especially worrisome that all that printing is done
under RCU lock and this can potentially trigger RCU stall or softlockup
detector.

The primary reason for the printk was to catch potential users who might
depend on the behavior prior to 44a70adec910 ("mm, oom_adj: make sure
processes sharing mm have same view of oom_score_adj") but after more
than 2 years without a single report I guess it is safe to simply remove
the printk altogether.

The next step should be moving oom_score_adj over to the mm struct and
remove all the tasks crawling as suggested by [2]

[1] http://lkml.kernel.org/r/97fce864-6f75-bca5-14bc-12c9f890e740@i-love.sakura.ne.jp
[2] http://lkml.kernel.org/r/20190117155159.GA4087@dhcp22.suse.cz

Link: http://lkml.kernel.org/r/20190212102129.26288-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Reported-by: Tetsuo Handa 
Acked-by: Johannes Weiner 
Cc: David Rientjes 
Cc: Yong-Taek Lee 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ceph: avoid repeatedly adding inode to mdsc->snap_flush_list

2019-02-27T09:08:50+00:00

commit 04242ff3ac0abbaa4362f97781dac268e6c3541a upstream.

Otherwise, mdsc->snap_flush_list may get corrupted.

Cc: stable@vger.kernel.org
Signed-off-by: "Yan, Zheng" 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

mm: proc: smaps_rollup: fix pss_locked calculation

2019-02-20T09:25:50+00:00

commit 27dd768ed8db48beefc4d9e006c58e7a00342bde upstream.

The 'pss_locked' field of smaps_rollup was being calculated incorrectly.
It accumulated the current pss everytime a locked VMA was found.  Fix
that by adding to 'pss_locked' the same time as that of 'pss' if the vma
being walked is locked.

Link: http://lkml.kernel.org/r/20190203065425.14650-1-sspatil@android.com
Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup")
Signed-off-by: Sandeep Patil 
Acked-by: Vlastimil Babka 
Reviewed-by: Joel Fernandes (Google) 
Cc: Alexey Dobriyan 
Cc: Daniel Colascione 
Cc: 	[4.14.x, 4.19.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Revert "mm: don't reclaim inodes with many attached pages"

2019-02-20T09:25:47+00:00

commit 69056ee6a8a3d576ed31e38b3b14c70d6c74edcc upstream.

This reverts commit a76cf1a474d7d ("mm: don't reclaim inodes with many
attached pages").

This change causes serious changes to page cache and inode cache
behaviour and balance, resulting in major performance regressions when
combining worklaods such as large file copies and kernel compiles.

  https://bugzilla.kernel.org/show_bug.cgi?id=202441

This change is a hack to work around the problems introduced by changing
how agressive shrinkers are on small caches in commit 172b06c32b94 ("mm:
slowly shrink slabs with a relatively small number of objects").  It
creates more problems than it solves, wasn't adequately reviewed or
tested, so it needs to be reverted.

Link: http://lkml.kernel.org/r/20190130041707.27750-2-david@fromorbit.com
Fixes: a76cf1a474d7d ("mm: don't reclaim inodes with many attached pages")
Signed-off-by: Dave Chinner 
Cc: Wolfgang Walter 
Cc: Roman Gushchin 
Cc: Spock 
Cc: Rik van Riel 
Cc: Michal Hocko 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Revert "nfsd4: return default lease period"

2019-02-20T09:25:47+00:00

commit 3bf6b57ec2ec945e5a6edf5c202a754f1e852ecd upstream.

This reverts commit d6ebf5088f09472c1136cd506bdc27034a6763f8.

I forgot that the kernel's default lease period should never be
decreased!

After a kernel upgrade, the kernel has no way of knowing on its own what
the previous lease time was.  Unless userspace tells it otherwise, it
will assume the previous lease period was the same.

So if we decrease this value in a kernel upgrade, we end up enforcing a
grace period that's too short, and clients will fail to reclaim state in
time.  Symptoms may include EIO and log messages like "NFS:
nfs4_reclaim_open_state: Lock reclaim failed!"

There was no real justification for the lease period decrease anyway.

Reported-by: Donald Buczek 
Fixes: d6ebf5088f09 "nfsd4: return default lease period"
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

CIFS: Do not assume one credit for async responses

2019-02-20T09:25:44+00:00

[ Upstream commit 0fd1d37b0501efc6e295f56ab55cdaff784aa50c ]

If we don't receive a response we can't assume that the server
granted one credit. Assume zero credits in such cases.

Signed-off-by: Pavel Shilovsky 
Reviewed-by: Ronnie Sahlberg 
Signed-off-by: Steve French 
Signed-off-by: Sasha Levin

cifs: Limit memory used by lock request calls to a page

2019-02-20T09:25:43+00:00

[ Upstream commit 92a8109e4d3a34fb6b115c9098b51767dc933444 ]

The code tries to allocate a contiguous buffer with a size supplied by
the server (maxBuf). This could fail if memory is fragmented since it
results in high order allocations for commonly used server
implementations. It is also wasteful since there are probably
few locks in the usual case. Limit the buffer to be no larger than a
page to avoid memory allocation failures due to fragmentation.

Signed-off-by: Ross Lagerwall 
Signed-off-by: Steve French 
Signed-off-by: Sasha Levin

Revert "exec: load_script: don't blindly truncate shebang string"

2019-02-15T08:09:54+00:00

commit cb5b020a8d38f77209d0472a0fea755299a8ec78 upstream.

This reverts commit 8099b047ecc431518b9bb6bdbba3549bbecdc343.

It turns out that people do actually depend on the shebang string being
truncated, and on the fact that an interpreter (like perl) will often
just re-interpret it entirely to get the full argument list.

Reported-by: Samuel Dionne-Riel 
Acked-by: Kees Cook 
Cc: Oleg Nesterov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman