linux-stable.git/include/linux, branch v4.10.6

give up on gcc ilog2() constant optimizations

2017-03-26T11:08:10+00:00

commit 474c90156c8dcc2fa815e6716cc9394d7930cb9c upstream.

gcc-7 has an "optimization" pass that completely screws up, and
generates the code expansion for the (impossible) case of calling
ilog2() with a zero constant, even when the code gcc compiles does not
actually have a zero constant.

And we try to generate a compile-time error for anybody doing ilog2() on
a constant where that doesn't make sense (be it zero or negative).  So
now gcc7 will fail the build due to our sanity checking, because it
created that constant-zero case that didn't actually exist in the source
code.

There's a whole long discussion on the kernel mailing about how to work
around this gcc bug.  The gcc people themselevs have discussed their
"feature" in

   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72785

but it's all water under the bridge, because while it looked at one
point like it would be solved by the time gcc7 was released, that was
not to be.

So now we have to deal with this compiler braindamage.

And the only simple approach seems to be to just delete the code that
tries to warn about bad uses of ilog2().

So now "ilog2()" will just return 0 not just for the value 1, but for
any non-positive value too.

It's not like I can recall anybody having ever actually tried to use
this function on any invalid value, but maybe the sanity check just
meant that such code never made it out in public.

Reported-by: Laura Abbott 
Cc: John Stultz ,
Cc: Thomas Gleixner 
Cc: Ard Biesheuvel 
Signed-off-by: Linus Torvalds 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

dccp: fix use-after-free in dccp_feat_activate_values

2017-03-22T11:57:00+00:00

[ Upstream commit 62f8f4d9066c1c6f2474845d1ca7e2891f2ae3fd ]

Dmitry reported crashes in DCCP stack [1]

Problem here is that when I got rid of listener spinlock, I missed the
fact that DCCP stores a complex state in struct dccp_request_sock,
while TCP does not.

Since multiple cpus could access it at the same time, we need to add
protection.

[1]
BUG: KASAN: use-after-free in dccp_feat_activate_values+0x967/0xab0
net/dccp/feat.c:1541 at addr ffff88003713be68
Read of size 8 by task syz-executor2/8457
CPU: 2 PID: 8457 Comm: syz-executor2 Not tainted 4.10.0-rc7+ #127
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:15 [inline]
 dump_stack+0x292/0x398 lib/dump_stack.c:51
 kasan_object_err+0x1c/0x70 mm/kasan/report.c:162
 print_address_description mm/kasan/report.c:200 [inline]
 kasan_report_error mm/kasan/report.c:289 [inline]
 kasan_report.part.1+0x20e/0x4e0 mm/kasan/report.c:311
 kasan_report mm/kasan/report.c:332 [inline]
 __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:332
 dccp_feat_activate_values+0x967/0xab0 net/dccp/feat.c:1541
 dccp_create_openreq_child+0x464/0x610 net/dccp/minisocks.c:121
 dccp_v6_request_recv_sock+0x1f6/0x1960 net/dccp/ipv6.c:457
 dccp_check_req+0x335/0x5a0 net/dccp/minisocks.c:186
 dccp_v6_rcv+0x69e/0x1d00 net/dccp/ipv6.c:711
 ip6_input_finish+0x46d/0x17a0 net/ipv6/ip6_input.c:279
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ip6_input+0xdb/0x590 net/ipv6/ip6_input.c:322
 dst_input include/net/dst.h:507 [inline]
 ip6_rcv_finish+0x289/0x890 net/ipv6/ip6_input.c:69
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ipv6_rcv+0x12ec/0x23d0 net/ipv6/ip6_input.c:203
 __netif_receive_skb_core+0x1ae5/0x3400 net/core/dev.c:4190
 __netif_receive_skb+0x2a/0x170 net/core/dev.c:4228
 process_backlog+0xe5/0x6c0 net/core/dev.c:4839
 napi_poll net/core/dev.c:5202 [inline]
 net_rx_action+0xe70/0x1900 net/core/dev.c:5267
 __do_softirq+0x2fb/0xb7d kernel/softirq.c:284
 do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:902
 
 do_softirq.part.17+0x1e8/0x230 kernel/softirq.c:328
 do_softirq kernel/softirq.c:176 [inline]
 __local_bh_enable_ip+0x1f2/0x200 kernel/softirq.c:181
 local_bh_enable include/linux/bottom_half.h:31 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:971 [inline]
 ip6_finish_output2+0xbb0/0x23d0 net/ipv6/ip6_output.c:123
 ip6_finish_output+0x302/0x960 net/ipv6/ip6_output.c:148
 NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 ip6_output+0x1cb/0x8d0 net/ipv6/ip6_output.c:162
 ip6_xmit+0xcdf/0x20d0 include/net/dst.h:501
 inet6_csk_xmit+0x320/0x5f0 net/ipv6/inet6_connection_sock.c:179
 dccp_transmit_skb+0xb09/0x1120 net/dccp/output.c:141
 dccp_xmit_packet+0x215/0x760 net/dccp/output.c:280
 dccp_write_xmit+0x168/0x1d0 net/dccp/output.c:362
 dccp_sendmsg+0x79c/0xb10 net/dccp/proto.c:796
 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744
 sock_sendmsg_nosec net/socket.c:635 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:645
 SYSC_sendto+0x660/0x810 net/socket.c:1687
 SyS_sendto+0x40/0x50 net/socket.c:1655
 entry_SYSCALL_64_fastpath+0x1f/0xc2
RIP: 0033:0x4458b9
RSP: 002b:00007f8ceb77bb58 EFLAGS: 00000282 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 00000000004458b9
RDX: 0000000000000023 RSI: 0000000020e60000 RDI: 0000000000000017
RBP: 00000000006e1b90 R08: 00000000200f9fe1 R09: 0000000000000020
R10: 0000000000008010 R11: 0000000000000282 R12: 00000000007080a8
R13: 0000000000000000 R14: 00007f8ceb77c9c0 R15: 00007f8ceb77c700
Object at ffff88003713be50, in cache kmalloc-64 size: 64
Allocated:
PID = 8446
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:502
 set_track mm/kasan/kasan.c:514 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:605
 kmem_cache_alloc_trace+0x82/0x270 mm/slub.c:2738
 kmalloc include/linux/slab.h:490 [inline]
 dccp_feat_entry_new+0x214/0x410 net/dccp/feat.c:467
 dccp_feat_push_change+0x38/0x220 net/dccp/feat.c:487
 __feat_register_sp+0x223/0x2f0 net/dccp/feat.c:741
 dccp_feat_propagate_ccid+0x22b/0x2b0 net/dccp/feat.c:949
 dccp_feat_server_ccid_dependencies+0x1b3/0x250 net/dccp/feat.c:1012
 dccp_make_response+0x1f1/0xc90 net/dccp/output.c:423
 dccp_v6_send_response+0x4ec/0xc20 net/dccp/ipv6.c:217
 dccp_v6_conn_request+0xaba/0x11b0 net/dccp/ipv6.c:377
 dccp_rcv_state_process+0x51e/0x1650 net/dccp/input.c:606
 dccp_v6_do_rcv+0x213/0x350 net/dccp/ipv6.c:632
 sk_backlog_rcv include/net/sock.h:893 [inline]
 __sk_receive_skb+0x36f/0xcc0 net/core/sock.c:479
 dccp_v6_rcv+0xba5/0x1d00 net/dccp/ipv6.c:742
 ip6_input_finish+0x46d/0x17a0 net/ipv6/ip6_input.c:279
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ip6_input+0xdb/0x590 net/ipv6/ip6_input.c:322
 dst_input include/net/dst.h:507 [inline]
 ip6_rcv_finish+0x289/0x890 net/ipv6/ip6_input.c:69
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ipv6_rcv+0x12ec/0x23d0 net/ipv6/ip6_input.c:203
 __netif_receive_skb_core+0x1ae5/0x3400 net/core/dev.c:4190
 __netif_receive_skb+0x2a/0x170 net/core/dev.c:4228
 process_backlog+0xe5/0x6c0 net/core/dev.c:4839
 napi_poll net/core/dev.c:5202 [inline]
 net_rx_action+0xe70/0x1900 net/core/dev.c:5267
 __do_softirq+0x2fb/0xb7d kernel/softirq.c:284
Freed:
PID = 15
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:502
 set_track mm/kasan/kasan.c:514 [inline]
 kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:578
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2954 [inline]
 kfree+0xe8/0x2b0 mm/slub.c:3874
 dccp_feat_entry_destructor.part.4+0x48/0x60 net/dccp/feat.c:418
 dccp_feat_entry_destructor net/dccp/feat.c:416 [inline]
 dccp_feat_list_pop net/dccp/feat.c:541 [inline]
 dccp_feat_activate_values+0x57f/0xab0 net/dccp/feat.c:1543
 dccp_create_openreq_child+0x464/0x610 net/dccp/minisocks.c:121
 dccp_v6_request_recv_sock+0x1f6/0x1960 net/dccp/ipv6.c:457
 dccp_check_req+0x335/0x5a0 net/dccp/minisocks.c:186
 dccp_v6_rcv+0x69e/0x1d00 net/dccp/ipv6.c:711
 ip6_input_finish+0x46d/0x17a0 net/ipv6/ip6_input.c:279
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ip6_input+0xdb/0x590 net/ipv6/ip6_input.c:322
 dst_input include/net/dst.h:507 [inline]
 ip6_rcv_finish+0x289/0x890 net/ipv6/ip6_input.c:69
 NF_HOOK include/linux/netfilter.h:257 [inline]
 ipv6_rcv+0x12ec/0x23d0 net/ipv6/ip6_input.c:203
 __netif_receive_skb_core+0x1ae5/0x3400 net/core/dev.c:4190
 __netif_receive_skb+0x2a/0x170 net/core/dev.c:4228
 process_backlog+0xe5/0x6c0 net/core/dev.c:4839
 napi_poll net/core/dev.c:5202 [inline]
 net_rx_action+0xe70/0x1900 net/core/dev.c:5267
 __do_softirq+0x2fb/0xb7d kernel/softirq.c:284
Memory state around the buggy address:
 ffff88003713bd00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88003713bd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88003713be00: fc fc fc fc fc fc fc fc fc fc fb fb fb fb fb fb
                                                          ^

Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet 
Reported-by: Dmitry Vyukov 
Tested-by: Dmitry Vyukov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ucount: Remove the atomicity from ucount->count

2017-03-18T11:18:38+00:00

commit 040757f738e13caaa9c5078bca79aa97e11dde88 upstream.

Always increment/decrement ucount->count under the ucounts_lock.  The
increments are there already and moving the decrements there means the
locking logic of the code is simpler.  This simplification in the
locking logic fixes a race between put_ucounts and get_ucounts that
could result in a use-after-free because the count could go zero then
be found by get_ucounts and then be freed by put_ucounts.

A bug presumably this one was found by a combination of syzkaller and
KASAN.  JongWhan Kim reported the syzkaller failure and Dmitry Vyukov
spotted the race in the code.

Fixes: f6b2db1a3e8d ("userns: Make the count of user namespaces per user")
Reported-by: JongHwan Kim 
Reported-by: Dmitry Vyukov 
Reviewed-by: Andrei Vagin 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

libceph: use BUG() instead of BUG_ON(1)

2017-03-15T02:20:19+00:00

commit d24cdcd3e40a6825135498e11c20c7976b9bf545 upstream.

I ran into this compile warning, which is the result of BUG_ON(1)
not always leading to the compiler treating the code path as
unreachable:

    include/linux/ceph/osdmap.h: In function 'ceph_can_shift_osds':
    include/linux/ceph/osdmap.h:62:1: error: control reaches end of non-void function [-Werror=return-type]

Using BUG() here avoids the warning.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Ilya Dryomov 
Cc: Heinrich Schuchardt 
Signed-off-by: Greg Kroah-Hartman

nfit, libnvdimm: fix interleave set cookie calculation

2017-03-15T02:20:13+00:00

commit 86ef58a4e35e8fa66afb5898cf6dec6a3bb29f67 upstream.

The interleave-set cookie is a sum that sanity checks the composition of
an interleave set has not changed from when the namespace was initially
created.  The checksum is calculated by sorting the DIMMs by their
location in the interleave-set. The comparison for the sort must be
64-bit wide, not byte-by-byte as performed by memcmp() in the broken
case.

Fix the implementation to accept correct cookie values in addition to
the Linux "memcmp" order cookies, but only allow correct cookies to be
generated going forward. It does mean that namespaces created by
third-party-tooling, or created by newer kernels with this fix, will not
validate on older kernels. However, there are a couple mitigating
conditions:

    1/ platforms with namespace-label capable NVDIMMs are not widely
       available.

    2/ interleave-sets with a single-dimm are by definition not affected
       (nothing to sort). This covers the QEMU-KVM NVDIMM emulation case.

The cookie stored in the namespace label will be fixed by any write the
namespace label, the most straightforward way to achieve this is to
write to the "alt_name" attribute of a namespace in sysfs.

Fixes: eaf961536e16 ("libnvdimm, nfit: add interleave-set state-tracking infrastructure")
Reported-by: Nicholas Moulin 
Tested-by: Nicholas Moulin 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

nlm: Ensure callback code also checks that the files match

2017-03-15T02:20:13+00:00

commit 251af29c320d86071664f02c76f0d063a19fefdf upstream.

It is not sufficient to just check that the lock pids match when
granting a callback, we also need to ensure that we're granting
the callback on the right file.

Reported-by: Pankaj Singh 
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Trond Myklebust 
Signed-off-by: Anna Schumaker 
Signed-off-by: Greg Kroah-Hartman

fs: Better permission checking for submounts

2017-03-15T02:20:10+00:00

commit 93faccbbfa958a9668d3ab4e30f38dd205cee8d8 upstream.

To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.

The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.

Attempting to handle the automount case by using override_creds
almost works.  It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.

Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.

vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.

sget and sget_userns are modified to not perform any permission checks
on submounts.

follow_automount is modified to stop using override_creds as that
has proven problemantic.

do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.

autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.

cifs is modified to pass the mountpoint all of the way down to vfs_submount.

debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter.  To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.

Fixes: 069d5ac9ae0d ("autofs:  Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust 
Reviewed-by: Seth Forshee 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

mtd: nand: ifc: Fix location of eccstat registers for IFC V1.0

2017-03-12T05:44:20+00:00

commit 656441478ed55d960df5f3ccdf5a0f8c61dfd0b3 upstream.

The commit 7a654172161c ("mtd/ifc: Add support for IFC controller
version 2.0") added support for version 2.0 of the IFC controller.
The version 2.0 controller has the ECC status registers at a different
location to the previous versions.

Correct the fsl_ifc_nand structure so that the ECC status can be read
from the correct location for both version 1.0 and 2.0 of the controller.

Fixes: 7a654172161c ("mtd/ifc: Add support for IFC controller version 2.0")
Signed-off-by: Mark Marshall 
Signed-off-by: Boris Brezillon 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Fix a rescind handling bug

2017-03-12T05:44:17+00:00

commit ccb61f8a99e6c29df4fb96a65dad4fad740d5be9 upstream.

The host can rescind a channel that has been offered to the
guest and once the channel is rescinded, the host does not
respond to any requests on that channel. Deal with the case where
the guest may be blocked waiting for a response from the host.

Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Fix available_governor sysfs

2017-03-12T05:44:11+00:00

commit bcf23c79c4e46130701370af4383b61a3cba755c upstream.

The devfreq using passive governor is not able to change the governor.
So, the user can not change the governor through 'available_governor' sysfs
entry. Also, the devfreq which don't use the passive governor is not able to
change to 'passive' governor on the fly.

Fixes: 996133119f57 ("PM / devfreq: Add new passive governor")
Signed-off-by: Chanwoo Choi 
Signed-off-by: MyungJoo Ham 
Signed-off-by: Greg Kroah-Hartman