linux.git, branch v4.9.56

Linux 4.9.56

2017-10-12T19:24:22+00:00

Revert "socket, bpf: fix possible use after free"

2017-10-12T19:21:39+00:00

This reverts commit 02f7e4101092b88e57c73171174976c8a72a3eba, which was
commit 02f7e4101092b88e57c73171174976c8a72a3eba upstream

Turns out the backport to 4.9 was broken.

Reported-by: Shuah Khan 
Signed-off-by: Greg Kroah-Hartman

Linux 4.9.55

2017-10-12T09:51:27+00:00

KVM: x86: fix singlestepping over syscall

2017-10-12T09:51:26+00:00

commit c8401dda2f0a00cd25c0af6a95ed50e478d25de4 upstream.

TF is handled a bit differently for syscall and sysret, compared
to the other instructions: TF is checked after the instruction completes,
so that the OS can disable #DB at a syscall by adding TF to FMASK.
When the sysret is executed the #DB is taken "as if" the syscall insn
just completed.

KVM emulates syscall so that it can trap 32-bit syscall on Intel processors.
Fix the behavior, otherwise you could get #DB on a user stack which is not
nice.  This does not affect Linux guests, as they use an IST or task gate
for #DB.

This fixes CVE-2017-7518.

Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Radim Krčmář 
[bwh: Backported to 4.9:
 - kvm_vcpu_check_singlestep() sets some flags differently
 - Drop changes to kvm_skip_emulated_instruction()]
Cc: Ben Hutchings 
Cc: Salvatore Bonaccorso 
Signed-off-by: Greg Kroah-Hartman

f2fs: don't allow encrypted operations without keys

2017-10-12T09:51:26+00:00

commit 363fa4e078cbdc97a172c19d19dc04b41b52ebc8 upstream.

This patch fixes the renaming bug on encrypted filenames, which was pointed by

 (ext4: don't allow encrypted operations without keys)

Cc: Theodore Ts'o 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim 
Signed-off-by: Greg Kroah-Hartman

ext4: don't allow encrypted operations without keys

2017-10-12T09:51:26+00:00

commit 173b8439e1ba362007315868928bf9d26e5cc5a6 upstream.

While we allow deletes without the key, the following should not be
permitted:

# cd /vdc/encrypted-dir-without-key
# ls -l
total 4
-rw-r--r-- 1 root root   0 Dec 27 22:35 6,LKNRJsp209FbXoSvJWzB
-rw-r--r-- 1 root root 286 Dec 27 22:35 uRJ5vJh9gE7vcomYMqTAyD
# mv uRJ5vJh9gE7vcomYMqTAyD  6,LKNRJsp209FbXoSvJWzB

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: Don't clear SGID when inheriting ACLs

2017-10-12T09:51:26+00:00

commit a3bb2d5587521eea6dab2d05326abb0afb460abd upstream.

When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by moving posix_acl_update_mode() out of
__ext4_set_acl() into ext4_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.

Fixes: 073931017b49d9458aa351605b43a7e34598caef
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jan Kara 
Reviewed-by: Andreas Gruenbacher 
Signed-off-by: Greg Kroah-Hartman

ext4: fix data corruption for mmap writes

2017-10-12T09:51:26+00:00

commit a056bdaae7a181f7dcc876cfab2f94538e508709 upstream.

mpage_submit_page() can race with another process growing i_size and
writing data via mmap to the written-back page. As mpage_submit_page()
samples i_size too early, it may happen that ext4_bio_write_page()
zeroes out too large tail of the page and thus corrupts user data.

Fix the problem by sampling i_size only after the page has been
write-protected in page tables by clear_page_dirty_for_io() call.

Reported-by: Michael Zimmer 
Fixes: cb20d5188366f04d96d2e07b1240cc92170ade40
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

vfs: deny copy_file_range() for non regular files

2017-10-12T09:51:26+00:00

commit 11cbfb10775aa2a01cee966d118049ede9d0bdf2 upstream.

There is no in-tree file system that implements copy_file_range()
for non regular files.

Deny an attempt to copy_file_range() a directory with EISDIR
and any other non regualr file with EINVAL to conform with
behavior of vfs_{clone,dedup}_file_range().

This change is needed prior to converting sb_start_write()
to  file_start_write() in the vfs helper.

Cc: linux-api@vger.kernel.org
Cc: Al Viro 
Signed-off-by: Amir Goldstein 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Miklos Szeredi 
Cc: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

sched/cpuset/pm: Fix cpuset vs. suspend-resume bugs

2017-10-12T09:51:25+00:00

commit 50e76632339d4655859523a39249dd95ee5e93e7 upstream.

Cpusets vs. suspend-resume is _completely_ broken. And it got noticed
because it now resulted in non-cpuset usage breaking too.

On suspend cpuset_cpu_inactive() doesn't call into
cpuset_update_active_cpus() because it doesn't want to move tasks about,
there is no need, all tasks are frozen and won't run again until after
we've resumed everything.

But this means that when we finally do call into
cpuset_update_active_cpus() after resuming the last frozen cpu in
cpuset_cpu_active(), the top_cpuset will not have any difference with
the cpu_active_mask and this it will not in fact do _anything_.

So the cpuset configuration will not be restored. This was largely
hidden because we would unconditionally create identity domains and
mobile users would not in fact use cpusets much. And servers what do use
cpusets tend to not suspend-resume much.

An addition problem is that we'd not in fact wait for the cpuset work to
finish before resuming the tasks, allowing spurious migrations outside
of the specified domains.

Fix the rebuild by introducing cpuset_force_rebuild() and fix the
ordering with cpuset_wait_for_hotplug().

Reported-by: Andy Lutomirski 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: 
Cc: Andy Lutomirski 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Fixes: deb7aa308ea2 ("cpuset: reorganize CPU / memory hotplug handling")
Link: http://lkml.kernel.org/r/20170907091338.orwxrqkbfkki3c24@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar 
Signed-off-by: Mike Galbraith 
Signed-off-by: Greg Kroah-Hartman