Commit Graph

54612 Commits

Author SHA1 Message Date
Richard Weinberger
54169ddd38 ubifs: Turn two ubifs_assert() into a WARN_ON()
We are going to pass struct ubifs_info to ubifs_assert()
but while unloading the UBIFS module we don't have the info
struct anymore.
Therefore replace the asserts by a regular WARN_ON().

Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:21 +02:00
Richard Weinberger
a3d218280c ubifs: Use kmalloc_array()
Since commit 6da2ec5605 ("treewide: kmalloc() -> kmalloc_array()")
we use kmalloc_array() for kmalloc() that computes the length with
a multiplication.

Cc: Kees Cook <keescook@chromium.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:20 +02:00
Richard Weinberger
95a22d2084 ubifs: Check data node size before truncate
Check whether the size is within bounds before using it.
If the size is not correct, abort and dump the bad data node.

Cc: Kees Cook <keescook@chromium.org>
Cc: Silvio Cesare <silvio.cesare@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Reported-by: Silvio Cesare <silvio.cesare@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:20 +02:00
Richard Weinberger
08acbdd6fd Revert "UBIFS: Fix potential integer overflow in allocation"
This reverts commit 353748a359.
It bypassed the linux-mtd review process and fixes the issue not as it
should.

Cc: Kees Cook <keescook@chromium.org>
Cc: Silvio Cesare <silvio.cesare@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:20 +02:00
Richard Weinberger
49d2e05fb4 ubifs: Add comment on c->commit_sem
Every single time I come across that code, I get confused
because it looks like a possible dead lock.
Help myself by adding a comment.

Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:20 +02:00
Stefan Agner
7e5471ce6d ubifs: introduce Kconfig symbol for xattr support
Allow to disable extended attribute support.

This aids in reliability testing, especially since some xattr
related bugs have surfaced.

Also an embedded system might not need it, so this allows for a
slightly smaller kernel (about 4KiB).

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:14 +02:00
Gustavo A. R. Silva
1bf0572fe2 ubifs: use swap macro in swap_dirty_idx
Make use of the swap macro and remove unnecessary variable *t*. This
makes the code easier to read and maintain.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:25:08 +02:00
Arnd Bergmann
6cff573202 ubifs: tnc: use monotonic znode timestamp
The tnc uses get_seconds() based timestamps to check the age of a znode,
which has two problems: on 32-bit architectures this may overflow in
2038 or 2106, and it gives incorrect information when the system time
is updated using settimeofday().

Using montonic timestamps with ktime_get_seconds() solves both thes
problems.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:16 +02:00
Arnd Bergmann
0eca0b8067 ubifs: use timespec64 for inode timestamps
Both vfs and the on-disk inode structures can deal with fine-grained
timestamps now, so this is the last missing piece to make ubifs
y2038-safe on 32-bit architectures.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:16 +02:00
Richard Weinberger
11a6fc3dc7 ubifs: xattr: Don't operate on deleted inodes
xattr operations can race with unlink and the following assert triggers:
UBIFS assert failed in ubifs_jnl_change_xattr at 1606 (pid 6256)

Fix this by checking i_nlink before working on the host inode.

Cc: <stable@vger.kernel.org>
Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:15 +02:00
Richard Weinberger
312c39bd6d ubifs: gc: Fix typo
UBIFS operates on LEBs, not PEBs.

Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:15 +02:00
Richard Weinberger
eef19816ad ubifs: Fix memory leak in lprobs self-check
Allocate the buffer after we return early.
Otherwise memory is being leaked.

Cc: <stable@vger.kernel.org>
Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:15 +02:00
Richard Weinberger
5996559320 ubifs: Fix synced_i_size calculation for xattr inodes
In ubifs_jnl_update() we sync parent and child inodes to the flash,
in case of xattrs, the parent inode (AKA host inode) has a non-zero
data_len. Therefore we need to adjust synced_i_size too.

This issue was reported by ubifs self tests unter a xattr related work
load.
UBIFS error (ubi0:0 pid 1896): dbg_check_synced_i_size: ui_size is 4, synced_i_size is 0, but inode is clean
UBIFS error (ubi0:0 pid 1896): dbg_check_synced_i_size: i_ino 65, i_mode 0x81a4, i_size 4

Cc: <stable@vger.kernel.org>
Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:15 +02:00
Richard Weinberger
00ee8b6010 ubifs: Fix directory size calculation for symlinks
We have to account the name of the symlink and not the target length.

Fixes: ca7f85be8d ("ubifs: Add support for encrypted symlinks")
Cc: <stable@vger.kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2018-08-15 00:06:15 +02:00
Linus Torvalds
d6dd643159 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
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
2018-08-12 11:21:17 -07:00
Al Viro
4c0d7cd5c8 make sure that __dentry_kill() always invalidates d_seq, unhashed or not
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: "Dae R. Jeong" <threeearcat@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-09 18:07:15 -04:00
Al Viro
119e1ef80e fix __legitimize_mnt()/mntput() race
__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: Oleg Nesterov <oleg@redhat.com>
Fixes: 48a066e72d ("RCU'd vsfmounts")
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-09 17:51:32 -04:00
Al Viro
9ea0a46ca2 fix mntput/mntput race
mntput_no_expire() does the calculation of total refcount under mount_lock;
unfortunately, the decrement (as well as all increments) are done outside
of it, leading to false positives in the "are we dropping the last reference"
test.  Consider the following situation:
	* mnt is a lazy-umounted mount, kept alive by two opened files.  One
of those files gets closed.  Total refcount of mnt is 2.  On CPU 42
mntput(mnt) (called from __fput()) drops one reference, decrementing component
	* After it has looked at component #0, the process on CPU 0 does
mntget(), incrementing component #0, gets preempted and gets to run again -
on CPU 69.  There it does mntput(), which drops the reference (component #69)
and proceeds to spin on mount_lock.
	* On CPU 42 our first mntput() finishes counting.  It observes the
decrement of component #69, but not the increment of component #0.  As the
result, the total it gets is not 1 as it should've been - it's 0.  At which
point we decide that vfsmount needs to be killed and proceed to free it and
shut the filesystem down.  However, there's still another opened file
on that filesystem, with reference to (now freed) vfsmount, etc. and we are
screwed.

It's not a wide race, but it can be reproduced with artificial slowdown of
the mnt_get_count() loop, and it should be easier to hit on SMP KVM setups.

Fix consists of moving the refcount decrement under mount_lock; the tricky
part is that we want (and can) keep the fast case (i.e. mount that still
has non-NULL ->mnt_ns) entirely out of mount_lock.  All places that zero
mnt->mnt_ns are dropping some reference to mnt and they call synchronize_rcu()
before that mntput().  IOW, if mntput() observes (under rcu_read_lock())
a non-NULL ->mnt_ns, it is guaranteed that there is another reference yet to
be dropped.

Reported-by: Jann Horn <jannh@google.com>
Tested-by: Jann Horn <jannh@google.com>
Fixes: 48a066e72d ("RCU'd vsfmounts")
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-09 17:21:17 -04:00
Al Viro
90bad5e05b root dentries need RCU-delayed freeing
Since mountpoint crossing can happen without leaving lazy mode,
root dentries do need the same protection against having their
memory freed without RCU delay as everything else in the tree.

It's partially hidden by RCU delay between detaching from the
mount tree and dropping the vfsmount reference, but the starting
point of pathwalk can be on an already detached mount, in which
case umount-caused RCU delay has already passed by the time the
lazy pathwalk grabs rcu_read_lock().  If the starting point
happens to be at the root of that vfsmount *and* that vfsmount
covers the entire filesystem, we get trouble.

Fixes: 48a066e72d ("RCU'd vsfmounts")
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-08-06 09:13:32 -04:00
Linus Torvalds
60f5a21736 - Fix JFS usercopy whitelist (it needed to cover neighboring field too) for
"overflow" inline inode data.
 -----BEGIN PGP SIGNATURE-----
 Comment: Kees Cook <kees@outflux.net>
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAltlv70WHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJj3eD/9+goWbs9U62tlO2cIqT5lgTFX9
 3vvVpqNJ3atw/fU6SZoa0Z2nRa9TIpZEfEljgARGhCyd2p2MplLJalWo6bq/gUUA
 5aWQbVxhyVXUp8kh8m3OnZsAZz658Y5geLMk8vakXdyQ//PF43wO0cZyOFYdG3ec
 sYuWA318UKaIsxqB9tT/K8YBRjjBgJ8wjgtpoSAr+FUhgg9Qqp3NL4fjr6SOEQrv
 XWXLVLLhyUo8kQJ29E/VyzIfLysgiA67O4ClW+DEyD6rr/ZK9XOeG6yv3vwLGSHI
 06/4BXMJce23iGIYf57Jz7b5tfAaZntdzNqUiTW6up0TuvG09auwjv/hKkwfjQv2
 fNf0TVnYOCN4ZWbCm4FTEU5q31u+pZDHiRxOTJG9EbuBVEsFiV5X9B9VTLoA+dWK
 SqWmE2X9YdONt9q6K8TGpxxrdQnQXGKOOtEY23KoF04XGYQtutIfj7cdFCDDX/eC
 AjcOIfV3u8dHWjc/wKIYS5XRUzbkdpEeNOaiCQ3RN79JN2UrA0/w7lAxZTICmYCs
 HtMtaFTER5weKQGzTzg0SP3M95qKPdWhlIq5lspdhGedonZAKBNfGahMltTH2UoY
 vIb1qGT8uz8tQSzGsu0uvrR92ZIJZ0qUVjB/nhE9HxTz26xqtDDlLXpdIXTGrnU4
 hM+Omud//MNgNbsmrg==
 =pwq8
 -----END PGP SIGNATURE-----

Merge tag 'usercopy-fix-v4.18-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull usercopy whitelisting fix from Kees Cook:
 "Bart Massey discovered that the usercopy whitelist for JFS was
  incomplete: the inline inode data may intentionally "overflow" into
  the neighboring "extended area", so the size of the whitelist needed
  to be raised to include the neighboring field"

* tag 'usercopy-fix-v4.18-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  jfs: Fix usercopy whitelist for inline inode data
2018-08-04 18:34:55 -07:00
Linus Torvalds
f639bef55d Changes since last update:
- Fix incorrect shifting in the iomap bmap functions.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAltj7lcACgkQ+H93GTRK
 tOutzw//U9yOrUhuOTFrkmA2x+CB1ArncFZysUTXDFUsLRrMp0dwNaRV0WafyypO
 tCr4nvqgwg2VTFf21zWblOSAajstgJzH+x3FdxTsU5Gktd/BH9gCHSDV0lORnFhp
 jbqNOsBRPJjNIBzaIIAnyDGMuOF/MeWpGsbGF4eDcsgj58lr098rir7grEVgCkKM
 +eCMtqJwUXUZ2bo/grBWvZXnLms+8LMPYeRQMJSnw59DVunwxRdSbWumJwkPt9DD
 mz3Upa/qFJCZw2n9kluU1b/tnrpxkNWYuSjzp9iu0cMdo52HF+yDNHriUPCHa4PB
 3KfyGrhOvg+iC2pUAJ5mI3Dpv+NNAk7j/+4mOVtlUYIf0mi5gszIjNHbLiONKVH5
 5x8G59wM/ae6a1WcHe7tJRma7r984G+JLTIxAQnWaWhFq5AsYMOplk4oq6X7Lmir
 wAR7laDN0Xgl3WCFj6SXaKcnuzZFsE4A3SnZILtlgO/WxAujUyFEnICx1cO4Q9OY
 64txWii6ora9kdBtalolxjfGHwyScbhx6FiBQdKIznxGgBQR89X8hzxghdp7KTIx
 kxkC1hAM3KXXtokArjad2hgd8QG23jUshyBwKpfHnEwL75GiZQ3qtPdDm/oJlVWV
 ItnRSt+tGIT/fsT5szNPmLKgtIW4kQHflVuih0KR4IsGPMmZ8dU=
 =3omy
 -----END PGP SIGNATURE-----

Merge tag 'xfs-4.18-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs bugfix from Darrick Wong:
 "One more patch for 4.18 to fix a coding error in the iomap_bmap()
  function introduced in -rc1: fix incorrect shifting"

* tag 'xfs-4.18-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fs: fix iomap_bmap position calculation
2018-08-04 18:30:58 -07:00
Kees Cook
961b33c244 jfs: Fix usercopy whitelist for inline inode data
Bart Massey reported what turned out to be a usercopy whitelist false
positive in JFS when symlink contents exceeded 128 bytes. The inline
inode data (i_inline) is actually designed to overflow into the "extended
area" following it (i_inline_ea) when needed. So the whitelist needed to
be expanded to include both i_inline and i_inline_ea (the whole size
of which is calculated internally using IDATASIZE, 256, instead of
sizeof(i_inline), 128).

$ cd /mnt/jfs
$ touch $(perl -e 'print "B" x 250')
$ ln -s B* b
$ ls -l >/dev/null

[  249.436410] Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLUB object 'jfs_ip' (offset 616, size 250)!

Reported-by: Bart Massey <bart.massey@gmail.com>
Fixes: 8d2704d382 ("jfs: Define usercopy region in jfs_ip slab cache")
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: jfs-discussion@lists.sourceforge.net
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2018-08-04 07:53:46 -07:00
Linus Torvalds
310810ae19 NFS client bugfixes for Linux 4.18
Highlights include:
 
 Bugfixes:
 - Fix a NFSv4 file locking regression
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJbZFG/AAoJEA4mA3inWBJcyo8P/0MN6eRpDU2VCZheM7DgsN2L
 a7W/Phc1PjHoaqksQB4Zb3uMYQQCWAyvE/VB5nRJSF1ZQbKvv7kgkyqX+PxEG8LI
 Pp3igaVXzqkRj3eA33G1HXZCrymjf7sTb4CEdMgSUBe3wLXjrFPP4Og0RJ8YGhCG
 QBG0ZENwcseUk5bmbSpp9Ac60URy1si1pD1nB3z+zSQT2ViA8QHgzg3Hpwgm+0R7
 WG/QzIFoGoJ8J9sDX/tXdkwUT2Z3yusxXcwK7Be5dtUcu1codf+EaPxRNG55myRW
 J2fY+KIocgQK8lo3w9ok1sGTyN+YkS8eIQqTeZzg0Gty/LX7bwH/3ScCeQtbu9RH
 nAR2OJQkc/wJ8sJojmUmDnBgskvgWzdfxfxRGQwlnRMD0W3t0LUDCeIUZ/1OL69l
 4pgvFLaR5MRD/DS4sSftKcOpgH5KDTlfuUXA+PamELLAk93FWJEZTVI4hmUR02+h
 /0QoRE6FAraQ7IY9TuLd/Jj3wWmqvataL6JGuWSdmhd35PbRxxBun+5zCyj62BAM
 /h0SjrCMD+dhotcdiekHINNbNYRG6ukbswgP6zCtuq4icTCW8SMVNyI3mXUVQwF3
 hAc3FylKpdGkgSrK3unLnBSeBgGwnCy1PYtusx0MgJf/qhdPYsl0bwgZhcR1U01y
 WfyGrwoNhLEmxL6+zECQ
 =gMVX
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfix from Trond Myklebust:
 "Fix a NFSv4 file locking regression"

* tag 'nfs-for-4.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Fix _nfs4_do_setlk()
2018-08-03 10:42:01 -07:00
Mike Rapoport
31e810aa10 userfaultfd: remove uffd flags from vma->vm_flags if UFFD_EVENT_FORK fails
The fix in commit 0cbb4b4f4c ("userfaultfd: clear the
vma->vm_userfaultfd_ctx if UFFD_EVENT_FORK fails") cleared the
vma->vm_userfaultfd_ctx but kept userfaultfd flags in vma->vm_flags
that were copied from the parent process VMA.

As the result, there is an inconsistency between the values of
vma->vm_userfaultfd_ctx.ctx and vma->vm_flags which triggers BUG_ON
in userfaultfd_release().

Clearing the uffd flags from vma->vm_flags in case of UFFD_EVENT_FORK
failure resolves the issue.

Link: http://lkml.kernel.org/r/1532931975-25473-1-git-send-email-rppt@linux.vnet.ibm.com
Fixes: 0cbb4b4f4c ("userfaultfd: clear the vma->vm_userfaultfd_ctx if UFFD_EVENT_FORK fails")
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reported-by: syzbot+121be635a7a35ddb7dcb@syzkaller.appspotmail.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-02 16:03:40 -07:00
Eric Sandeen
79b3dbe4ad fs: fix iomap_bmap position calculation
The position calculation in iomap_bmap() shifts bno the wrong way,
so we don't progress properly and end up re-mapping block zero
over and over, yielding an unchanging physical block range as the
logical block advances:

# filefrag -Be file
 ext:   logical_offset:     physical_offset: length:   expected: flags:
   0:      0..       0:      21..        21:      1:             merged
   1:      1..       1:      21..        21:      1:         22: merged
Discontinuity: Block 1 is at 21 (was 22)
   2:      2..       2:      21..        21:      1:         22: merged
Discontinuity: Block 2 is at 21 (was 22)
   3:      3..       3:      21..        21:      1:         22: merged

This breaks the FIBMAP interface for anyone using it (XFS), which
in turn breaks LILO, zipl, etc.

Bug-actually-spotted-by: Darrick J. Wong <darrick.wong@oracle.com>
Fixes: 89eb1906a9 ("iomap: add an iomap-based bmap implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02 13:09:27 -07:00
Phillip Lougher
a3f94cb99a Squashfs: Compute expected length from inode size rather than block length
Previously in squashfs_readpage() when copying data into the page
cache, it used the length of the datablock read from the filesystem
(after decompression).  However, if the filesystem has been corrupted
this data block may be short, which will leave pages unfilled.

The fix for this is to compute the expected number of bytes to copy
from the inode size, and use this to detect if the block is short.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: Анатолий Тросиненко <anatoly.trosinenko@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-02 09:34:02 -07:00
Linus Torvalds
71755ee535 squashfs: more metadata hardening
The squashfs fragment reading code doesn't actually verify that the
fragment is inside the fragment table.  The end result _is_ verified to
be inside the image when actually reading the fragment data, but before
that is done, we may end up taking a page fault because the fragment
table itself might not even exist.

Another report from Anatoly and his endless squashfs image fuzzing.

Reported-by: Анатолий Тросиненко <anatoly.trosinenko@gmail.com>
Acked-by:: Phillip Lougher <phillip.lougher@gmail.com>,
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-02 09:32:23 -07:00
Trond Myklebust
6ea76bf513 NFSv4: Fix _nfs4_do_setlk()
The patch to fix the case where a lock request was interrupted ended up
changing default handling of errors such as NFS4ERR_DENIED and caused the
client to immediately resend the lock request. Let's do a partial revert
of that request so that the default is now to exit, but change the way
we handle resends to take into account the fact that the user may have
interrupted the request.

Reported-by: Kenneth Johansson <ken@kenjo.org>
Fixes: a3cf9bca2a ("NFSv4: Don't add a new lock on an interrupted wait..")
Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
2018-08-01 23:17:06 -04:00
Linus Torvalds
cdbb65c4c7 squashfs metadata 2: electric boogaloo
Anatoly continues to find issues with fuzzed squashfs images.

This time, corrupt, missing, or undersized data for the page filling
wasn't checked for, because the squashfs_{copy,read}_cache() functions
did the squashfs_copy_data() call without checking the resulting data
size.

Which could result in the page cache pages being incompletely filled in,
and no error indication to the user space reading garbage data.

So make a helper function for the "fill in pages" case, because the
exact same incomplete sequence existed in two places.

[ I should have made a squashfs branch for these things, but I didn't
  intend to start doing them in the first place.

  My historical connection through cramfs is why I got into looking at
  these issues at all, and every time I (continue to) think it's a
  one-off.

  Because _this_ time is always the last time. Right?   - Linus ]

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-01 10:38:43 -07:00
Linus Torvalds
d512584780 squashfs: more metadata hardening
Anatoly reports another squashfs fuzzing issue, where the decompression
parameters themselves are in a compressed block.

This causes squashfs_read_data() to be called in order to read the
decompression options before the decompression stream having been set
up, making squashfs go sideways.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Acked-by: Phillip Lougher <phillip.lougher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-30 17:29:17 -07:00
Linus Torvalds
3cfb6772d4 Some miscellaneous ext4 fixes for 4.18; one fix is for a regression
introduced in 4.18-rc4.
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEK2m5VNv+CHkogTfJ8vlZVpUNgaMFAlteF34ACgkQ8vlZVpUN
 gaMQugf+LjlbbncSEuPxZ+C3CnSGkEzjrg8IRylZA2uf04Z5Bax8K5gqvXLx7ZtF
 Qz3vzmrYpaUV8UiaMy0SGLCRWebwoxPEN7ZX3/W1PfeymP3wQ4DLw37059AzLfsq
 Vzh9w3N1At1plUee7iJ2MDBU830Q0a917jjnpZ+M0AtQx/BzP8QEISuzp4JWICqe
 NbJDVybMWoW2YOSpMPiihxSFqCDx5rMyAJ1vllboopZK+XAjpQ/visnLh3aT3o71
 7cTPl9gI2rbwYbJk8kM5fmXhWqSARHARV1bpZNOUnCAUU1E2Se7aETjggQ0QzJE/
 mIc7wCzFLrrY8+iakwdhb5Aw3qOPyg==
 =ZdXo
 -----END PGP SIGNATURE-----

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
 "Some miscellaneous ext4 fixes for 4.18; one fix is for a regression
  introduced in 4.18-rc4.

  Sorry for the late-breaking pull. I was originally going to wait for
  the next merge window, but Eric Whitney found a regression introduced
  in 4.18-rc4, so I decided to push out the regression plus the other
  fixes now. (The other commits have been baking in linux-next since
  early July)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix check to prevent initializing reserved inodes
  ext4: check for allocation block validity with block group locked
  ext4: fix inline data updates with checksums enabled
  ext4: clear mmp sequence number when remounting read-only
  ext4: fix false negatives *and* false positives in ext4_check_descriptors()
2018-07-29 13:13:45 -07:00
Linus Torvalds
01cfb7937a squashfs: be more careful about metadata corruption
Anatoly Trosinenko reports that a corrupted squashfs image can cause a
kernel oops.  It turns out that squashfs can end up being confused about
negative fragment lengths.

The regular squashfs_read_data() does check for negative lengths, but
squashfs_read_metadata() did not, and the fragment size code just
blindly trusted the on-disk value.  Fix both the fragment parsing and
the metadata reading code.

Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-29 12:44:46 -07:00
Theodore Ts'o
5012284700 ext4: fix check to prevent initializing reserved inodes
Commit 8844618d8a: "ext4: only look at the bg_flags field if it is
valid" will complain if block group zero does not have the
EXT4_BG_INODE_ZEROED flag set.  Unfortunately, this is not correct,
since a freshly created file system has this flag cleared.  It gets
almost immediately after the file system is mounted read-write --- but
the following somewhat unlikely sequence will end up triggering a
false positive report of a corrupted file system:

   mkfs.ext4 /dev/vdc
   mount -o ro /dev/vdc /vdc
   mount -o remount,rw /dev/vdc

Instead, when initializing the inode table for block group zero, test
to make sure that itable_unused count is not too large, since that is
the case that will result in some or all of the reserved inodes
getting cleared.

This fixes the failures reported by Eric Whiteney when running
generic/230 and generic/231 in the the nojournal test case.

Fixes: 8844618d8a ("ext4: only look at the bg_flags field if it is valid")
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-07-29 15:34:00 -04:00
Linus Torvalds
eb181a814c for-linus-20180727
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAltbc20QHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpgh4D/9GYQcjk9qLVFxkv5ucAUvCuxEL6gjsMf4W
 M/QdxVIrwh3zpvsH++2IXXn+xH+UjujMA5NkzhsSr4+hsSO2iAGOYMJbroNfhsTD
 onvQQ6NTaHPu/+PZs0otVK4KMWHwZGWOV6YU00TWTfRgzRmGEsSMe91oeBIXVv9w
 v6d09twaLSY0lUkAAbcdu5fuFBtXu4Bxy60qyHEKkAdWWHEUYaZLrODhVjoGg2V4
 KdAWS5X4A6kJMcPcoOvG6RFtpf71boaip9o/DRLUWhGdIQnI38UgSCUmz1XMYnik
 Sq8r74vqCm8IhIOLTlxnPrMHHbKv7JZhY3Ow9fxnS6HZRNI0aPX31Yml6NULqnWh
 MsQh+6gZXd3xC1O7txEQn4a15Lk0OLXa8HJcIn5ADNxqz5/r/g0mPUG9HmPSIalO
 ISFF/9UKQFcAd0RjHR+bEEH2VMznz59UWKfdOsmwFZtZSCmR1ucj0xAKDj+oP1JS
 ZsgZ09K2GezrL4GEueocISo9ACIWgDWH8T7/bTxlBok0IYbybAfmOe+MZInL1Tf4
 pklmoXm3ntgV3Pq8Ptk05LYyIgAaUIltuSiR3AFaXIADX0wNtV0ZgysIWgHf3BSA
 18j+I1yPG1IwBdM8xNwxi56xMQR84uY5tsIyafbfj+laRI2nH5OIYjNZnrKpm957
 4xZUgIECBA==
 =2ogY
 -----END PGP SIGNATURE-----

Merge tag 'for-linus-20180727' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Bigger than usual at this time, mostly due to the O_DIRECT corruption
  issue and the fact that I was on vacation last week. This contains:

   - NVMe pull request with two fixes for the FC code, and two target
     fixes (Christoph)

   - a DIF bio reset iteration fix (Greg Edwards)

   - two nbd reply and requeue fixes (Josef)

   - SCSI timeout fixup (Keith)

   - a small series that fixes an issue with bio_iov_iter_get_pages(),
     which ended up causing corruption for larger sized O_DIRECT writes
     that ended up racing with buffered writes (Martin Wilck)"

* tag 'for-linus-20180727' of git://git.kernel.dk/linux-block:
  block: reset bi_iter.bi_done after splitting bio
  block: bio_iov_iter_get_pages: pin more pages for multi-segment IOs
  blkdev: __blkdev_direct_IO_simple: fix leak in error case
  block: bio_iov_iter_get_pages: fix size of last iovec
  nvmet: only check for filebacking on -ENOTBLK
  nvmet: fixup crash on NULL device path
  scsi: set timed out out mq requests to complete
  blk-mq: export setting request completion state
  nvme: if_ready checks to fail io to deleting controller
  nvmet-fc: fix target sgl list on large transfers
  nbd: handle unexpected replies better
  nbd: don't requeue the same request twice.
2018-07-27 12:51:00 -07:00
Linus Torvalds
864af0d40c Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "11 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kvm, mm: account shadow page tables to kmemcg
  zswap: re-check zswap_is_full() after do zswap_shrink()
  include/linux/eventfd.h: include linux/errno.h
  mm: fix vma_is_anonymous() false-positives
  mm: use vma_init() to initialize VMAs on stack and data segments
  mm: introduce vma_init()
  mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL
  ipc/sem.c: prevent queue.status tearing in semop
  mm: disallow mappings that conflict for devm_memremap_pages()
  kasan: only select SLUB_DEBUG with SYSFS=y
  delayacct: fix crash in delayacct_blkio_end() after delayacct init failure
2018-07-27 10:30:47 -07:00
Linus Torvalds
f636d300cd Changes since last update:
- Fix some uninitialized variable errors
 - Fix an incorrect check in metadata verifiers
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEUzaAxoMeQq6m2jMV+H93GTRKtOsFAltYpkoACgkQ+H93GTRK
 tOsMAA//Tyt2rjGGrvtPUiI9xhDDbYM+Eds19IWhye9LyNQCHXdmrCicsBvoEyCC
 5XSAT5lofeLNIbiTS88aC0b4sr2LLban6YsTBHGTlRxUTrnCSpCCDIgXJswxLjmT
 jivIumvKL3sxgmXubwe6gnjoLCNGIy3JrdCu4vFf6JGWAj6U5HyZ5hjtj74nuPtg
 w6BMEptJIOmQwGzSjQY76dQ5ekliVuOtYISY6gRAfVPVvwURgIzZdQPi4qV5Kw/d
 n2nA6rvMBUcMUSVvXWS1ryOWsy4HrB9LXzbr5Kb0NgaVKnAqSCYGIGMJSEsiO/7Y
 P83Doo6N8fYh8QEUOLqJ76XTkkrzoo3fvo7IZXUGMERXx90UliEAI/k6hWy6awtT
 cCQatAcOp+8r5PvMJ9ZIivAwDId06PwpuDntOATIamGkNEo4vo0LO189fQP+i8RD
 LIbEcLcGOHVjjTZgGqJCfDWVPiFtG8ZdZp9bvmpW9aREzMGl/tXnvI2QsSwZu+lU
 87efBqztYGm4U4D5grdV/ynbT1E4E9ggtI2pVHG2ipJnZ+UeTiOCw68lDcUDT0JA
 lU2fPUKzUR3v+U6s26AJFKcX2HCG4G75cJozBuH82xcPnUT0m3PMde0ZhFzVnvg4
 w8T+bIS0Q/f310SSAitu1qfG5cx2f6I5j107jhldvcibRmqEZLE=
 =Ovtv
 -----END PGP SIGNATURE-----

Merge tag 'xfs-4.18-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:

 - Fix some uninitialized variable errors

 - Fix an incorrect check in metadata verifiers

* tag 'xfs-4.18-fixes-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: properly handle free inodes in extent hint validators
  xfs: Initialize variables in xfs_alloc_get_rec before using them
2018-07-27 09:25:09 -07:00
Kirill A. Shutemov
bfd40eaff5 mm: fix vma_is_anonymous() false-positives
vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous
VMA.  This is unreliable as ->mmap may not set ->vm_ops.

False-positive vma_is_anonymous() may lead to crashes:

	next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0
	prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000
	pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000
	flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare)
	------------[ cut here ]------------
	kernel BUG at mm/memory.c:1422!
	invalid opcode: 0000 [#1] SMP KASAN
	CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136
	Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
	01/01/2011
	RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline]
	RIP: 0010:zap_pud_range mm/memory.c:1466 [inline]
	RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline]
	RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508
	Call Trace:
	 unmap_single_vma+0x1a0/0x310 mm/memory.c:1553
	 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644
	 unmap_mapping_range_vma mm/memory.c:2792 [inline]
	 unmap_mapping_range_tree mm/memory.c:2813 [inline]
	 unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845
	 unmap_mapping_range+0x48/0x60 mm/memory.c:2880
	 truncate_pagecache+0x54/0x90 mm/truncate.c:800
	 truncate_setsize+0x70/0xb0 mm/truncate.c:826
	 simple_setattr+0xe9/0x110 fs/libfs.c:409
	 notify_change+0xf13/0x10f0 fs/attr.c:335
	 do_truncate+0x1ac/0x2b0 fs/open.c:63
	 do_sys_ftruncate+0x492/0x560 fs/open.c:205
	 __do_sys_ftruncate fs/open.c:215 [inline]
	 __se_sys_ftruncate fs/open.c:213 [inline]
	 __x64_sys_ftruncate+0x59/0x80 fs/open.c:213
	 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reproducer:

	#include <stdio.h>
	#include <stddef.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <fcntl.h>

	#define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
	#define KCOV_ENABLE			_IO('c', 100)
	#define KCOV_DISABLE			_IO('c', 101)
	#define COVER_SIZE			(1024<<10)

	#define KCOV_TRACE_PC  0
	#define KCOV_TRACE_CMP 1

	int main(int argc, char **argv)
	{
		int fd;
		unsigned long *cover;

		system("mount -t debugfs none /sys/kernel/debug");
		fd = open("/sys/kernel/debug/kcov", O_RDWR);
		ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE);
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		munmap(cover, COVER_SIZE * sizeof(unsigned long));
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		memset(cover, 0, COVER_SIZE * sizeof(unsigned long));
		ftruncate(fd, 3UL << 20);
		return 0;
	}

This can be fixed by assigning anonymous VMAs own vm_ops and not relying
on it being NULL.

If ->mmap() failed to set ->vm_ops, mmap_region() will set it to
dummy_vm_ops.  This way we will have non-NULL ->vm_ops for all VMAs.

Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Kirill A. Shutemov
2c4541e24c mm: use vma_init() to initialize VMAs on stack and data segments
Make sure to initialize all VMAs properly, not only those which come
from vm_area_cachep.

Link: http://lkml.kernel.org/r/20180724121139.62570-3-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Martin Wilck
9362dd1109 blkdev: __blkdev_direct_IO_simple: fix leak in error case
Fixes: 72ecad22d9 ("block: support a full bio worth of IO for simplified bdev direct-io")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-26 11:52:33 -06:00
Linus Torvalds
5c61ef1b7c fscache fixes
-----BEGIN PGP SIGNATURE-----
 
 iQIVAwUAW1h/7Pu3V2unywtrAQJFOg/+NQswGJcTsJGeTL8tW+8nGtJVeTP6XaVh
 xPEjdqTBmimt6ciaNP1LxLLt9jQ50S1f83rWGZeFBQoNgWinoe3VtzSVdlQKhZcT
 jC5LtFVlTxw5rrL4uCsJywLLjD0NeH41ISbvCStcyYJExOZr+f4/VJXKNcwKjAvf
 kD1xDGnVZsZiGLWFjwBVaPJwFigquoLEU564InMnZbvMW95uZOPGfnwxAGmKQX2n
 BV3WxVizCc0MwlHMJYjs0cVMZNviuC+qg7YBJIoio3+Dq8FIn7ISn98LbhCpG7mi
 FoiRi+7xs7VCGm9yqtkXL+euHcSzjnJPnlYxpU8xGqAay0qKxoHecZj2iMEX327K
 E4mujQ40oqkMLhwy3GhT9cIpvbbQPu7+kS+k9x7UqVnzlhsKEeMp7TEFqSEebO9H
 kIuvfRBD3uZY0B/loLCB3Cc/B9OoWAUi6IGBRclwS9+RUuBnZY/jb7iQsEvcOv9u
 0EC0biSs1jizG1tLR0LmvjIyvS567t/DG/peLad1lOqPe6Up2mO4XIeyS9phwXAD
 ryupnKPr3tGRgvfJ4jLUZPC8/nrv5Fg9R0YhICEEBqhwKn1uTZgyc085d2EHOdQp
 fmfbXR/oz4TwjjwlgzrLMQbLB7GUpkgCFxsIPpEVeFH3RDbZNO1UbLovDMUuRaos
 lFWHzd4K4XA=
 =yuI9
 -----END PGP SIGNATURE-----

Merge tag 'fscache-fixes-20180725' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull fscache/cachefiles fixes from David Howells:

 - Allow cancelled operations to be queued so they can be cleaned up.

 - Fix a refcounting bug in the monitoring of reads on backend files
   whereby a race can occur between monitor objects being listed for
   work, the work processing being queued and the work processor running
   and destroying the monitor objects.

 - Fix a ref overput in object attachment, whereby a tentatively
   considered object is put in error handling without first being 'got'.

 - Fix a missing clear of the CACHEFILES_OBJECT_ACTIVE flag whereby an
   assertion occurs when we retry because it seems the object is now
   active.

 - Wait rather BUG'ing on an object collision in the depths of
   cachefiles as the active object should be being cleaned up - also
   depends on the one above.

* tag 'fscache-fixes-20180725' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  cachefiles: Wait rather than BUG'ing on "Unexpected object collision"
  cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flag
  fscache: Fix reference overput in fscache_attach_object() error handling
  cachefiles: Fix refcounting bug in backing-file read monitoring
  fscache: Allow cancelled operations to be enqueued
2018-07-25 10:55:24 -07:00
Kiran Kumar Modukuri
c2412ac45a cachefiles: Wait rather than BUG'ing on "Unexpected object collision"
If we meet a conflicting object that is marked FSCACHE_OBJECT_IS_LIVE in
the active object tree, we have been emitting a BUG after logging
information about it and the new object.

Instead, we should wait for the CACHEFILES_OBJECT_ACTIVE flag to be cleared
on the old object (or return an error).  The ACTIVE flag should be cleared
after it has been removed from the active object tree.  A timeout of 60s is
used in the wait, so we shouldn't be able to get stuck there.

Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25 14:49:00 +01:00
Kiran Kumar Modukuri
5ce83d4bb7 cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flag
In cachefiles_mark_object_active(), the new object is marked active and
then we try to add it to the active object tree.  If a conflicting object
is already present, we want to wait for that to go away.  After the wait,
we go round again and try to re-mark the object as being active - but it's
already marked active from the first time we went through and a BUG is
issued.

Fix this by clearing the CACHEFILES_OBJECT_ACTIVE flag before we try again.

Analysis from Kiran Kumar Modukuri:

[Impact]
Oops during heavy NFS + FSCache + Cachefiles

CacheFiles: Error: Overlong wait for old active object to go away.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000002

CacheFiles: Error: Object already active kernel BUG at
fs/cachefiles/namei.c:163!

[Cause]
In a heavily loaded system with big files being read and truncated, an
fscache object for a cookie is being dropped and a new object being
looked. The new object being looked for has to wait for the old object
to go away before the new object is moved to active state.

[Fix]
Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when
retrying the object lookup.

[Testcase]
Have run ~100 hours of NFS stress tests and have not seen this bug recur.

[Regression Potential]
 - Limited to fscache/cachefiles.

Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25 14:49:00 +01:00
Kiran Kumar Modukuri
f29507ce66 fscache: Fix reference overput in fscache_attach_object() error handling
When a cookie is allocated that causes fscache_object structs to be
allocated, those objects are initialised with the cookie pointer, but
aren't blessed with a ref on that cookie unless the attachment is
successfully completed in fscache_attach_object().

If attachment fails because the parent object was dying or there was a
collision, fscache_attach_object() returns without incrementing the cookie
counter - but upon failure of this function, the object is released which
then puts the cookie, whether or not a ref was taken on the cookie.

Fix this by taking a ref on the cookie when it is assigned in
fscache_object_init(), even when we're creating a root object.


Analysis from Kiran Kumar:

This bug has been seen in 4.4.0-124-generic #148-Ubuntu kernel

BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776277

fscache cookie ref count updated incorrectly during fscache object
allocation resulting in following Oops.

kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/internal.h:321!
kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!

[Cause]
Two threads are trying to do operate on a cookie and two objects.

(1) One thread tries to unmount the filesystem and in process goes over a
    huge list of objects marking them dead and deleting the objects.
    cookie->usage is also decremented in following path:

      nfs_fscache_release_super_cookie
       -> __fscache_relinquish_cookie
        ->__fscache_cookie_put
        ->BUG_ON(atomic_read(&cookie->usage) <= 0);

(2) A second thread tries to lookup an object for reading data in following
    path:

    fscache_alloc_object
    1) cachefiles_alloc_object
        -> fscache_object_init
           -> assign cookie, but usage not bumped.
    2) fscache_attach_object -> fails in cant_attach_object because the
         cookie's backing object or cookie's->parent object are going away
    3) fscache_put_object
        -> cachefiles_put_object
          ->fscache_object_destroy
            ->fscache_cookie_put
               ->BUG_ON(atomic_read(&cookie->usage) <= 0);

[NOTE from dhowells] It's unclear as to the circumstances in which (2) can
take place, given that thread (1) is in nfs_kill_super(), however a
conflicting NFS mount with slightly different parameters that creates a
different superblock would do it.  A backtrace from Kiran seems to show
that this is a possibility:

    kernel BUG at/build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639!
    ...
    RIP: __fscache_cookie_put+0x3a/0x40 [fscache]
    Call Trace:
     __fscache_relinquish_cookie+0x87/0x120 [fscache]
     nfs_fscache_release_super_cookie+0x2d/0xb0 [nfs]
     nfs_kill_super+0x29/0x40 [nfs]
     deactivate_locked_super+0x48/0x80
     deactivate_super+0x5c/0x60
     cleanup_mnt+0x3f/0x90
     __cleanup_mnt+0x12/0x20
     task_work_run+0x86/0xb0
     exit_to_usermode_loop+0xc2/0xd0
     syscall_return_slowpath+0x4e/0x60
     int_ret_from_sys_call+0x25/0x9f

[Fix] Bump up the cookie usage in fscache_object_init, when it is first
being assigned a cookie atomically such that the cookie is added and bumped
up if its refcount is not zero.  Remove the assignment in
fscache_attach_object().

[Testcase]
I have run ~100 hours of NFS stress tests and not seen this bug recur.

[Regression Potential]
 - Limited to fscache/cachefiles.

Fixes: ccc4fc3d11 ("FS-Cache: Implement the cookie management part of the netfs API")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25 14:49:00 +01:00
Kiran Kumar Modukuri
934140ab02 cachefiles: Fix refcounting bug in backing-file read monitoring
cachefiles_read_waiter() has the right to access a 'monitor' object by
virtue of being called under the waitqueue lock for one of the pages in its
purview.  However, it has no ref on that monitor object or on the
associated operation.

What it is allowed to do is to move the monitor object to the operation's
to_do list, but once it drops the work_lock, it's actually no longer
permitted to access that object.  However, it is trying to enqueue the
retrieval operation for processing - but it can only do this via a pointer
in the monitor object, something it shouldn't be doing.

If it doesn't enqueue the operation, the operation may not get processed.
If the order is flipped so that the enqueue is first, then it's possible
for the work processor to look at the to_do list before the monitor is
enqueued upon it.

Fix this by getting a ref on the operation so that we can trust that it
will still be there once we've added the monitor to the to_do list and
dropped the work_lock.  The op can then be enqueued after the lock is
dropped.

The bug can manifest in one of a couple of ways.  The first manifestation
looks like:

 FS-Cache:
 FS-Cache: Assertion failed
 FS-Cache: 6 == 5 is false
 ------------[ cut here ]------------
 kernel BUG at fs/fscache/operation.c:494!
 RIP: 0010:fscache_put_operation+0x1e3/0x1f0
 ...
 fscache_op_work_func+0x26/0x50
 process_one_work+0x131/0x290
 worker_thread+0x45/0x360
 kthread+0xf8/0x130
 ? create_worker+0x190/0x190
 ? kthread_cancel_work_sync+0x10/0x10
 ret_from_fork+0x1f/0x30

This is due to the operation being in the DEAD state (6) rather than
INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through
fscache_put_operation().

The bug can also manifest like the following:

 kernel BUG at fs/fscache/operation.c:69!
 ...
    [exception RIP: fscache_enqueue_operation+246]
 ...
 #7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6
 #8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48
 #9 [ffff883fff083c48] __wake_up_common at ffffffff810af028

I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not
entirely clear which assertion failed.

Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Lei Xue <carmark.dlut@gmail.com>
Reported-by: Vegard Nossum <vegard.nossum@gmail.com>
Reported-by: Anthony DeRobertis <aderobertis@metrics.net>
Reported-by: NeilBrown <neilb@suse.com>
Reported-by: Daniel Axtens <dja@axtens.net>
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
2018-07-25 14:49:00 +01:00
Kiran Kumar Modukuri
d0eb06afe7 fscache: Allow cancelled operations to be enqueued
Alter the state-check assertion in fscache_enqueue_operation() to allow
cancelled operations to be given processing time so they can be cleaned up.

Also fix a debugging statement that was requiring such operations to have
an object assigned.

Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25 14:31:20 +01:00
Eric Sandeen
d4a34e1655 xfs: properly handle free inodes in extent hint validators
When inodes are freed in xfs_ifree(), di_flags is cleared (so extent size
hints are removed) but the actual extent size fields are left intact.
This causes the extent hint validators to fail on freed inodes which once
had extent size hints.

This can be observed (for example) by running xfs/229 twice on a
non-crc xfs filesystem, or presumably on V5 with ikeep.

Fixes: 7d71a67 ("xfs: verify extent size hint is valid in inode verifier")
Fixes: 02a0fda ("xfs: verify COW extent size hint is valid in inode verifier")
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-24 11:34:52 -07:00
Linus Torvalds
165ea0d1c2 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Fix several places that screw up cleanups after failures halfway
  through opening a file (one open-coding filp_clone_open() and getting
  it wrong, two misusing alloc_file()). That part is -stable fodder from
  the 'work.open' branch.

  And Christoph's regression fix for uapi breakage in aio series;
  include/uapi/linux/aio_abi.h shouldn't be pulling in the kernel
  definition of sigset_t, the reason for doing so in the first place had
  been bogus - there's no need to expose struct __aio_sigset in
  aio_abi.h at all"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: don't expose __aio_sigset in uapi
  ocxlflash_getfile(): fix double-iput() on alloc_file() failures
  cxl_getfile(): fix double-iput() on alloc_file() failures
  drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open()
2018-07-22 12:04:51 -07:00
Linus Torvalds
55b636b419 for-4.18-rc5-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAltSwkIACgkQxWXV+ddt
 WDtMBQ//UXMjHaXvFmC0SM6NczuYQR51hLYtJFIKig93XK5goVpUBTNbxO7LX/Tn
 4zKoKyVhkW1884V6mRiC+G23QLbo0BQZA7DExfyJ3jylQdjZMBm+K+r19OtGQf5v
 CII7oUwni03KIiXIqiFAL5dLWebVQpG5EKJbh8GLZsmg6xNcyVaUqZ/fHXajbZiv
 ldEBtHBKIv7WWTJmylMBKMWnRz+jqU91fXPahoU6R5qivODrLt1o/PMuSjVNhaxe
 iDldHfdOaiQmLHB/1kOGyv492oW5mSSVNDE8LjEDZ61tDNlAcUyuKUWIRBxDEDtD
 6D7rlVQXJ/N7sJ6+UYmJKsRpHL+NOkyzSZ0QEU/sm1Xpm8gkhHuuofRPrVCtd3l1
 ZSbwvlrdyjigVEBfM3IbToQ/K6Rc1ZGId20OAs9PCQbb+mj9IxPIncZ7pI1c4hlh
 pPEjcYsp14JbCTjctFalcqTiFY5tHRQsx+GUFnDyOcdL7Mi+CoH+0Jy61Vgz9GQE
 7s934cfEC0ot/f66kAL/PZzxUfC7TePqaa+sDfS5BIkJ4M6lPMxS5De5R4Z0+Nzr
 DXgQAlgXmxfRjpOYMTH9D0EDdSeJaNmVHgk7hFbiYk/KX3oyd4NmgI9Cfao8rQJv
 2yd8wF2httfSJKD4b/Hv9r6Ho/Bw9PK59BvWOKYhSj6IGl32utw=
 =f7eB
 -----END PGP SIGNATURE-----

Merge tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "A fix of a corruption regarding fsync and clone, under some very
  specific conditions explained in the patch.

  The fix is marked for stable 3.16+ so I'd like to get it merged now
  given the impact"

* tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix file data corruption after cloning a range and fsync
2018-07-21 16:42:03 -07:00
Linus Torvalds
490fc05386 mm: make vm_area_alloc() initialize core fields
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 15:24:03 -07:00
Linus Torvalds
3928d4f5ee mm: use helper functions for allocating and freeing vm_area structs
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 13:48:51 -07:00