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  1. 27 Nov, 2018 29 commits
  3. 21 Nov, 2018 11 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.164 · 8e592f4a
      Greg Kroah-Hartman authored
      8e592f4a
    • Clint Taylor's avatar
      drm/i915/hdmi: Add HDMI 2.0 audio clock recovery N values · 29a23181
      Clint Taylor authored 
      commit 65034931 upstream.

HDMI 2.0 594Mhz modes were incorrectly selecting 25.200Mhz Automatic N value
mode instead of HDMI specification values.

V2: Fix 88.2 Hz N value

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarClint Taylor <clinton.a.taylor@intel.com>
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1540493521-1746-2-git-send-email-clinton.a.taylor@intel.com
(cherry picked from commit 5a400aa3)
Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      29a23181
    • Stanislav Lisovskiy's avatar
      drm/dp_mst: Check if primary mstb is null · 8ef21c40
      Stanislav Lisovskiy authored 
      commit 23d80039 upstream.

Unfortunately drm_dp_get_mst_branch_device which is called from both
drm_dp_mst_handle_down_rep and drm_dp_mst_handle_up_rep seem to rely
on that mgr->mst_primary is not NULL, which seem to be wrong as it can be
cleared with simultaneous mode set, if probing fails or in other case.
mgr->lock mutex doesn't protect against that as it might just get
assigned to NULL right before, not simultaneously.

There are currently bugs 107738, 108616 bugs which crash in
drm_dp_get_mst_branch_device, caused by this issue.

v2: Refactored the code, as it was nicely noticed.
    Fixed Bugzilla bug numbers(second was 108616, but not 108816)
    and added links.

[changed title and added stable cc]
Signed-off-by: default avatarLyude Paul <lyude@redhat.com>
Signed-off-by: default avatarStanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108616
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107738
Link: https://patchwork.freedesktop.org/patch/msgid/20181109090012.24438-1-stanislav.lisovskiy@intel.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8ef21c40
    • Marc Zyngier's avatar
      drm/rockchip: Allow driver to be shutdown on reboot/kexec · 67dbeda8
      Marc Zyngier authored 
      commit 7f3ef5de upstream.

Leaving the DRM driver enabled on reboot or kexec has the annoying
effect of leaving the display generating transactions whilst the
IOMMU has been shut down.

In turn, the IOMMU driver (which shares its interrupt line with
the VOP) starts warning either on shutdown or when entering the
secondary kernel in the kexec case (nothing is expected on that
front).

A cheap way of ensuring that things are nicely shut down is to
register a shutdown callback in the platform driver.
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Tested-by: default avatarVicente Bergas <vicencb@gmail.com>
Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180805124807.18169-1-marc.zyngier@arm.com
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      67dbeda8
    • Mike Kravetz's avatar
      mm: migration: fix migration of huge PMD shared pages · b026c7ee
      Mike Kravetz authored 
      commit 017b1660 upstream.

The page migration code employs try_to_unmap() to try and unmap the source
page.  This is accomplished by using rmap_walk to find all vmas where the
page is mapped.  This search stops when page mapcount is zero.  For shared
PMD huge pages, the page map count is always 1 no matter the number of
mappings.  Shared mappings are tracked via the reference count of the PMD
page.  Therefore, try_to_unmap stops prematurely and does not completely
unmap all mappings of the source page.

This problem can result is data corruption as writes to the original
source page can happen after contents of the page are copied to the target
page.  Hence, data is lost.

This problem was originally seen as DB corruption of shared global areas
after a huge page was soft offlined due to ECC memory errors.  DB
developers noticed they could reproduce the issue by (hotplug) offlining
memory used to back huge pages.  A simple testcase can reproduce the
problem by creating a shared PMD mapping (note that this must be at least
PUD_SIZE in size and PUD_SIZE aligned (1GB on x86)), and using
migrate_pages() to migrate process pages between nodes while continually
writing to the huge pages being migrated.

To fix, have the try_to_unmap_one routine check for huge PMD sharing by
calling huge_pmd_unshare for hugetlbfs huge pages.  If it is a shared
mapping it will be 'unshared' which removes the page table entry and drops
the reference on the PMD page.  After this, flush caches and TLB.

mmu notifiers are called before locking page tables, but we can not be
sure of PMD sharing until page tables are locked.  Therefore, check for
the possibility of PMD sharing before locking so that notifiers can
prepare for the worst possible case.

Link: http://lkml.kernel.org/r/20180823205917.16297-2-mike.kravetz@oracle.com
[mike.kravetz@oracle.com: make _range_in_vma() a static inline]
  Link: http://lkml.kernel.org/r/6063f215-a5c8-2f0c-465a-2c515ddc952d@oracle.com
Fixes: 39dde65c ("shared page table for hugetlb page")
Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarJérôme Glisse <jglisse@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b026c7ee
    • Mike Kravetz's avatar
      hugetlbfs: fix kernel BUG at fs/hugetlbfs/inode.c:444! · 575361a2
      Mike Kravetz authored 
      commit 5e41540c upstream.

This bug has been experienced several times by the Oracle DB team.  The
BUG is in remove_inode_hugepages() as follows:

	/*
	 * If page is mapped, it was faulted in after being
	 * unmapped in caller.  Unmap (again) now after taking
	 * the fault mutex.  The mutex will prevent faults
	 * until we finish removing the page.
	 *
	 * This race can only happen in the hole punch case.
	 * Getting here in a truncate operation is a bug.
	 */
	if (unlikely(page_mapped(page))) {
		BUG_ON(truncate_op);

In this case, the elevated map count is not the result of a race.
Rather it was incorrectly incremented as the result of a bug in the huge
pmd sharing code.  Consider the following:

 - Process A maps a hugetlbfs file of sufficient size and alignment
   (PUD_SIZE) that a pmd page could be shared.

 - Process B maps the same hugetlbfs file with the same size and
   alignment such that a pmd page is shared.

 - Process B then calls mprotect() to change protections for the mapping
   with the shared pmd. As a result, the pmd is 'unshared'.

 - Process B then calls mprotect() again to chage protections for the
   mapping back to their original value. pmd remains unshared.

 - Process B then forks and process C is created. During the fork
   process, we do dup_mm -> dup_mmap -> copy_page_range to copy page
   tables. Copying page tables for hugetlb mappings is done in the
   routine copy_hugetlb_page_range.

In copy_hugetlb_page_range(), the destination pte is obtained by:

	dst_pte = huge_pte_alloc(dst, addr, sz);

If pmd sharing is possible, the returned pointer will be to a pte in an
existing page table.  In the situation above, process C could share with
either process A or process B.  Since process A is first in the list,
the returned pte is a pointer to a pte in process A's page table.

However, the check for pmd sharing in copy_hugetlb_page_range is:

	/* If the pagetables are shared don't copy or take references */
	if (dst_pte == src_pte)
		continue;

Since process C is sharing with process A instead of process B, the
above test fails.  The code in copy_hugetlb_page_range which follows
assumes dst_pte points to a huge_pte_none pte.  It copies the pte entry
from src_pte to dst_pte and increments this map count of the associated
page.  This is how we end up with an elevated map count.

To solve, check the dst_pte entry for huge_pte_none.  If !none, this
implies PMD sharing so do not copy.

Link: http://lkml.kernel.org/r/20181105212315.14125-1-mike.kravetz@oracle.com
Fixes: c5c99429 ("fix hugepages leak due to pagetable page sharing")
Signed-off-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: default avatarNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      575361a2
    • Guenter Roeck's avatar
      configfs: replace strncpy with memcpy · 9546d660
      Guenter Roeck authored 
      commit 1823342a upstream.

gcc 8.1.0 complains:

fs/configfs/symlink.c:67:3: warning:
	'strncpy' output truncated before terminating nul copying as many
	bytes from a string as its length
fs/configfs/symlink.c: In function 'configfs_get_link':
fs/configfs/symlink.c:63:13: note: length computed here

Using strncpy() is indeed less than perfect since the length of data to
be copied has already been determined with strlen(). Replace strncpy()
with memcpy() to address the warning and optimize the code a little.
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarNobuhiro Iwamatsu <nobuhiro.iwamatsu@cybertrust.co.jp>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9546d660
    • Miklos Szeredi's avatar
      fuse: fix leaked notify reply · 6023d16f
      Miklos Szeredi authored 
      commit 7fabaf30 upstream.

fuse_request_send_notify_reply() may fail if the connection was reset for
some reason (e.g. fs was unmounted).  Don't leak request reference in this
case.  Besides leaking memory, this resulted in fc->num_waiting not being
decremented and hence fuse_wait_aborted() left in a hanging and unkillable
state.

Fixes: 2d45ba38 ("fuse: add retrieve request")
Fixes: b8f95e5d ("fuse: umount should wait for all requests")
Reported-and-tested-by: syzbot+6339eda9cb4ebbc4c37b@syzkaller.appspotmail.com
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> #v2.6.36
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6023d16f
    • Maciej W. Rozycki's avatar
      rtc: hctosys: Add missing range error reporting · 453e01cc
      Maciej W. Rozycki authored 
      commit 7ce9a992 upstream.

Fix an issue with the 32-bit range error path in `rtc_hctosys' where no
error code is set and consequently the successful preceding call result
from `rtc_read_time' is propagated to `rtc_hctosys_ret'.  This in turn
makes any subsequent call to `hctosys_show' incorrectly report in sysfs
that the system time has been set from this RTC while it has not.

Set the error to ERANGE then if we can't express the result due to an
overflow.
Signed-off-by: default avatarMaciej W. Rozycki <macro@linux-mips.org>
Fixes: b3a5ac42 ("rtc: hctosys: Ensure system time doesn't overflow time_t")
Cc: stable@vger.kernel.org # 4.17+
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      453e01cc
    • Frank Sorenson's avatar
      sunrpc: correct the computation for page_ptr when truncating · 4293fbc2
      Frank Sorenson authored 
      commit 5d7a5bcb upstream.

When truncating the encode buffer, the page_ptr is getting
advanced, causing the next page to be skipped while encoding.
The page is still included in the response, so the response
contains a page of bogus data.

We need to adjust the page_ptr backwards to ensure we encode
the next page into the correct place.

We saw this triggered when concurrent directory modifications caused
nfsd4_encode_direct_fattr() to return nfserr_noent, and the resulting
call to xdr_truncate_encode() corrupted the READDIR reply.
Signed-off-by: default avatarFrank Sorenson <sorenson@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4293fbc2
    • Eric W. Biederman's avatar
      mount: Prevent MNT_DETACH from disconnecting locked mounts · f7e6ee2e
      Eric W. Biederman authored 
      commit 9c8e0a1b upstream.

Timothy Baldwin <timbaldwin@fastmail.co.uk> wrote:
> As per mount_namespaces(7) unprivileged users should not be able to look under mount points:
>
>   Mounts that come as a single unit from more privileged mount are locked
>   together and may not be separated in a less privileged mount namespace.
>
> However they can:
>
> 1. Create a mount namespace.
> 2. In the mount namespace open a file descriptor to the parent of a mount point.
> 3. Destroy the mount namespace.
> 4. Use the file descriptor to look under the mount point.
>
> I have reproduced this with Linux 4.16.18 and Linux 4.18-rc8.
>
> The setup:
>
> $ sudo sysctl kernel.unprivileged_userns_clone=1
> kernel.unprivileged_userns_clone = 1
> $ mkdir -p A/B/Secret
> $ sudo mount -t tmpfs hide A/B
>
>
> "Secret" is indeed hidden as expected:
>
> $ ls -lR A
> A:
> total 0
> drwxrwxrwt 2 root root 40 Feb 12 21:08 B
>
> A/B:
> total 0
>
>
> The attack revealing "Secret":
>
> $ unshare -Umr sh -c "exec unshare -m ls -lR /proc/self/fd/4/ 4<A"
> /proc/self/fd/4/:
> total 0
> drwxr-xr-x 3 root root 60 Feb 12 21:08 B
>
> /proc/self/fd/4/B:
> total 0
> drwxr-xr-x 2 root root 40 Feb 12 21:08 Secret
>
> /proc/self/fd/4/B/Secret:
> total 0

I tracked this down to put_mnt_ns running passing UMOUNT_SYNC and
disconnecting all of the mounts in a mount namespace.  Fix this by
factoring drop_mounts out of drop_collected_mounts and passing
0 instead of UMOUNT_SYNC.

There are two possible behavior differences that result from this.
- No longer setting UMOUNT_SYNC will no longer set MNT_SYNC_UMOUNT on
  the vfsmounts being unmounted.  This effects the lazy rcu walk by
  kicking the walk out of rcu mode and forcing it to be a non-lazy
  walk.
- No longer disconnecting locked mounts will keep some mounts around
  longer as they stay because the are locked to other mounts.

There are only two users of drop_collected mounts: audit_tree.c and
put_mnt_ns.

In audit_tree.c the mounts are private and there are no rcu lazy walks
only calls to iterate_mounts. So the changes should have no effect
except for a small timing effect as the connected mounts are disconnected.

In put_mnt_ns there may be references from process outside the mount
namespace to the mounts.  So the mounts remaining connected will
be the bug fix that is needed.  That rcu walks are allowed to continue
appears not to be a problem especially as the rcu walk change was about
an implementation detail not about semantics.

Cc: stable@vger.kernel.org
Fixes: 5ff9d8a6 ("vfs: Lock in place mounts from more privileged users")
Reported-by: default avatarTimothy Baldwin <timbaldwin@fastmail.co.uk>
Tested-by: default avatarTimothy Baldwin <timbaldwin@fastmail.co.uk>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f7e6ee2e
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