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[PATCH 4.9 00/21] 4.9.25-stable review

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  [PATCH 4.9 00/21] 4.9.25-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:20 +0200
    [PATCH 4.9 16/21] mac80211: fix MU-MIMO follow-MAC mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 20/21] x86/mce: Make the MCE notifier a blocking one Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 03/21] KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 06/21] mm: prevent NR_ISOLATE_* stats from going negative Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 14/21] ubifs: Fix O_TMPFILE corner case in ubifs_link() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 19/21] x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 18/21] powerpc/kprobe: Fix oops when kprobed on stdu instruction Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 13/21] ubifs: Fix RENAME_WHITEOUT support Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 17/21] ubi/upd: Always flush after prepared for an update Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 07/21] cifs: Do not send echoes before Negotiate is complete Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 02/21] KEYS: Change the name of the dead type to ".dead" to prevent user access Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 21/21] device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:30 +0200
    [PATCH 4.9 01/21] KEYS: Disallow keyrings beginning with . to be joined as session keyrings Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:40 +0200
    [PATCH 4.9 10/21] Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-25 17:40 +0200
    Re: [PATCH 4.9 00/21] 4.9.25-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-04-25 20:30 +0200
    Re: [PATCH 4.9 00/21] 4.9.25-stable review Guenter Roeck <linux@roeck-us.net> - 2017-04-26 04:30 +0200

#1630635 — [PATCH 4.9 00/21] 4.9.25-stable review

This is the start of the stable review cycle for the 4.9.25 release.
There are 21 patches in this series, all will be posted as a response
to this one.  If anyone has any issues with these being applied, please
let me know.

Responses should be made by Thu Apr 27 15:08:14 UTC 2017.
Anything received after that time might be too late.

The whole patch series can be found in one patch at:
	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.25-rc1.gz
or in the git tree and branch at:
  git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.9.y
and the diffstat can be found below.

thanks,

greg k-h

-------------
Pseudo-Shortlog of commits:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Linux 4.9.25-rc1

Dan Williams <dan.j.williams@intel.com>
    device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation

Vishal Verma <vishal.l.verma@intel.com>
    x86/mce: Make the MCE notifier a blocking one

Yazen Ghannam <yazen.ghannam@amd.com>
    x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs

Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
    powerpc/kprobe: Fix oops when kprobed on 'stdu' instruction

Sebastian Siewior <bigeasy@linutronix.de>
    ubi/upd: Always flush after prepared for an update

Johannes Berg <johannes.berg@intel.com>
    mac80211: fix MU-MIMO follow-MAC mode

Johannes Berg <johannes.berg@intel.com>
    mac80211: reject ToDS broadcast data frames

Richard Weinberger <richard@nod.at>
    ubifs: Fix O_TMPFILE corner case in ubifs_link()

Felix Fietkau <nbd@nbd.name>
    ubifs: Fix RENAME_WHITEOUT support

Haibo Chen <haibo.chen@nxp.com>
    mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

Arnd Bergmann <arnd@arndb.de>
    ACPI / power: Avoid maybe-uninitialized warning

Thorsten Leemhuis <linux@leemhuis.info>
    Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled

Christian Borntraeger <borntraeger@de.ibm.com>
    s390/mm: fix CMMA vs KSM vs others

Germano Percossi <germano.percossi@citrix.com>
    CIFS: remove bad_network_name flag

Sachin Prabhu <sprabhu@redhat.com>
    cifs: Do not send echoes before Negotiate is complete

Rabin Vincent <rabinv@axis.com>
    mm: prevent NR_ISOLATE_* stats from going negative

Steven Rostedt (VMware) <rostedt@goodmis.org>
    ring-buffer: Have ring_buffer_iter_empty() return true when empty

Steven Rostedt (VMware) <rostedt@goodmis.org>
    tracing: Allocate the snapshot buffer before enabling probe

Eric Biggers <ebiggers@google.com>
    KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings

David Howells <dhowells@redhat.com>
    KEYS: Change the name of the dead type to ".dead" to prevent user access

David Howells <dhowells@redhat.com>
    KEYS: Disallow keyrings beginning with '.' to be joined as session keyrings


-------------

Diffstat:

 Makefile                                  |  4 +-
 arch/powerpc/kernel/entry_64.S            |  6 +--
 arch/s390/include/asm/pgtable.h           |  2 +
 arch/x86/kernel/cpu/mcheck/mce-genpool.c  |  2 +-
 arch/x86/kernel/cpu/mcheck/mce-internal.h |  2 +-
 arch/x86/kernel/cpu/mcheck/mce.c          | 16 ++----
 arch/x86/kernel/cpu/mcheck/mce_amd.c      |  2 +-
 drivers/acpi/power.c                      |  1 +
 drivers/dax/Kconfig                       |  1 +
 drivers/dax/dax.c                         | 13 ++---
 drivers/input/mouse/elantech.c            |  8 +++
 drivers/mmc/host/sdhci-esdhc-imx.c        |  1 +
 drivers/mtd/ubi/upd.c                     |  8 +--
 fs/cifs/cifsglob.h                        |  1 -
 fs/cifs/smb1ops.c                         | 10 ++++
 fs/cifs/smb2pdu.c                         |  5 --
 fs/ubifs/dir.c                            | 10 ++--
 kernel/trace/ring_buffer.c                | 16 +++++-
 kernel/trace/trace.c                      |  8 +--
 mm/migrate.c                              |  2 +-
 net/mac80211/rx.c                         | 86 ++++++++++++++++++++++++-------
 security/keys/gc.c                        |  2 +-
 security/keys/keyctl.c                    | 20 +++----
 security/keys/process_keys.c              | 44 ++++++++++------
 24 files changed, 179 insertions(+), 91 deletions(-)

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#1630646 — [PATCH 4.9 16/21] mac80211: fix MU-MIMO follow-MAC mode

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.berg@intel.com>

commit 9e478066eae41211c92a8f63cc69aafc391bd6ab upstream.

There are two bugs in the follow-MAC code:
 * it treats the radiotap header as the 802.11 header
   (therefore it can't possibly work)
 * it doesn't verify that the skb data it accesses is actually
   present in the header, which is mitigated by the first point

Fix this by moving all of this out into a separate function.
This function copies the data it needs using skb_copy_bits()
to make sure it can be accessed if it's paged, and offsets
that by the possibly present vendor radiotap header.

This also makes all those conditions more readable.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/mac80211/rx.c |   65 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 47 insertions(+), 18 deletions(-)

--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -208,6 +208,51 @@ ieee80211_rx_radiotap_hdrlen(struct ieee
 	return len;
 }
 
+static void ieee80211_handle_mu_mimo_mon(struct ieee80211_sub_if_data *sdata,
+					 struct sk_buff *skb,
+					 int rtap_vendor_space)
+{
+	struct {
+		struct ieee80211_hdr_3addr hdr;
+		u8 category;
+		u8 action_code;
+	} __packed action;
+
+	if (!sdata)
+		return;
+
+	BUILD_BUG_ON(sizeof(action) != IEEE80211_MIN_ACTION_SIZE + 1);
+
+	if (skb->len < rtap_vendor_space + sizeof(action) +
+		       VHT_MUMIMO_GROUPS_DATA_LEN)
+		return;
+
+	if (!is_valid_ether_addr(sdata->u.mntr.mu_follow_addr))
+		return;
+
+	skb_copy_bits(skb, rtap_vendor_space, &action, sizeof(action));
+
+	if (!ieee80211_is_action(action.hdr.frame_control))
+		return;
+
+	if (action.category != WLAN_CATEGORY_VHT)
+		return;
+
+	if (action.action_code != WLAN_VHT_ACTION_GROUPID_MGMT)
+		return;
+
+	if (!ether_addr_equal(action.hdr.addr1, sdata->u.mntr.mu_follow_addr))
+		return;
+
+	skb = skb_copy(skb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
+	skb_queue_tail(&sdata->skb_queue, skb);
+	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
+}
+
 /*
  * ieee80211_add_rx_radiotap_header - add radiotap header
  *
@@ -515,7 +560,6 @@ ieee80211_rx_monitor(struct ieee80211_lo
 	struct net_device *prev_dev = NULL;
 	int present_fcs_len = 0;
 	unsigned int rtap_vendor_space = 0;
-	struct ieee80211_mgmt *mgmt;
 	struct ieee80211_sub_if_data *monitor_sdata =
 		rcu_dereference(local->monitor_sdata);
 
@@ -553,6 +597,8 @@ ieee80211_rx_monitor(struct ieee80211_lo
 		return remove_monitor_info(local, origskb, rtap_vendor_space);
 	}
 
+	ieee80211_handle_mu_mimo_mon(monitor_sdata, origskb, rtap_vendor_space);
+
 	/* room for the radiotap header based on driver features */
 	rt_hdrlen = ieee80211_rx_radiotap_hdrlen(local, status, origskb);
 	needed_headroom = rt_hdrlen - rtap_vendor_space;
@@ -618,23 +664,6 @@ ieee80211_rx_monitor(struct ieee80211_lo
 		ieee80211_rx_stats(sdata->dev, skb->len);
 	}
 
-	mgmt = (void *)skb->data;
-	if (monitor_sdata &&
-	    skb->len >= IEEE80211_MIN_ACTION_SIZE + 1 + VHT_MUMIMO_GROUPS_DATA_LEN &&
-	    ieee80211_is_action(mgmt->frame_control) &&
-	    mgmt->u.action.category == WLAN_CATEGORY_VHT &&
-	    mgmt->u.action.u.vht_group_notif.action_code == WLAN_VHT_ACTION_GROUPID_MGMT &&
-	    is_valid_ether_addr(monitor_sdata->u.mntr.mu_follow_addr) &&
-	    ether_addr_equal(mgmt->da, monitor_sdata->u.mntr.mu_follow_addr)) {
-		struct sk_buff *mu_skb = skb_copy(skb, GFP_ATOMIC);
-
-		if (mu_skb) {
-			mu_skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
-			skb_queue_tail(&monitor_sdata->skb_queue, mu_skb);
-			ieee80211_queue_work(&local->hw, &monitor_sdata->work);
-		}
-	}
-
 	if (prev_dev) {
 		skb->dev = prev_dev;
 		netif_receive_skb(skb);

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#1630647 — [PATCH 4.9 20/21] x86/mce: Make the MCE notifier a blocking one

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vishal Verma <vishal.l.verma@intel.com>

commit 0dc9c639e6553e39c13b2c0d54c8a1b098cb95e2 upstream.

The NFIT MCE handler callback (for handling media errors on NVDIMMs)
takes a mutex to add the location of a memory error to a list. But since
the notifier call chain for machine checks (x86_mce_decoder_chain) is
atomic, we get a lockdep splat like:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
  in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
  [..]
  Call Trace:
   dump_stack
   ___might_sleep
   __might_sleep
   mutex_lock_nested
   ? __lock_acquire
   nfit_handle_mce
   notifier_call_chain
   atomic_notifier_call_chain
   ? atomic_notifier_call_chain
   mce_gen_pool_process

Convert the notifier to a blocking one which gets to run only in process
context.

Boris: remove the notifier call in atomic context in print_mce(). For
now, let's print the MCE on the atomic path so that we can make sure
they go out and get logged at least.

Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error")
Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.com
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/mcheck/mce-genpool.c  |    2 +-
 arch/x86/kernel/cpu/mcheck/mce-internal.h |    2 +-
 arch/x86/kernel/cpu/mcheck/mce.c          |   16 +++-------------
 3 files changed, 5 insertions(+), 15 deletions(-)

--- a/arch/x86/kernel/cpu/mcheck/mce-genpool.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-genpool.c
@@ -85,7 +85,7 @@ void mce_gen_pool_process(void)
 	head = llist_reverse_order(head);
 	llist_for_each_entry_safe(node, tmp, head, llnode) {
 		mce = &node->mce;
-		atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
+		blocking_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
 		gen_pool_free(mce_evt_pool, (unsigned long)node, sizeof(*node));
 	}
 }
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -13,7 +13,7 @@ enum severity_level {
 	MCE_PANIC_SEVERITY,
 };
 
-extern struct atomic_notifier_head x86_mce_decoder_chain;
+extern struct blocking_notifier_head x86_mce_decoder_chain;
 
 #define ATTR_LEN		16
 #define INITIAL_CHECK_INTERVAL	5 * 60 /* 5 minutes */
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -120,7 +120,7 @@ static void (*quirk_no_way_out)(int bank
  * CPU/chipset specific EDAC code can register a notifier call here to print
  * MCE errors in a human-readable form.
  */
-ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain);
+BLOCKING_NOTIFIER_HEAD(x86_mce_decoder_chain);
 
 /* Do initial initialization of a struct mce */
 void mce_setup(struct mce *m)
@@ -213,13 +213,13 @@ void mce_register_decode_chain(struct no
 	if (nb != &mce_srao_nb && nb->priority == INT_MAX)
 		nb->priority -= 1;
 
-	atomic_notifier_chain_register(&x86_mce_decoder_chain, nb);
+	blocking_notifier_chain_register(&x86_mce_decoder_chain, nb);
 }
 EXPORT_SYMBOL_GPL(mce_register_decode_chain);
 
 void mce_unregister_decode_chain(struct notifier_block *nb)
 {
-	atomic_notifier_chain_unregister(&x86_mce_decoder_chain, nb);
+	blocking_notifier_chain_unregister(&x86_mce_decoder_chain, nb);
 }
 EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
 
@@ -272,8 +272,6 @@ struct mca_msr_regs msr_ops = {
 
 static void print_mce(struct mce *m)
 {
-	int ret = 0;
-
 	pr_emerg(HW_ERR "CPU %d: Machine Check Exception: %Lx Bank %d: %016Lx\n",
 	       m->extcpu, m->mcgstatus, m->bank, m->status);
 
@@ -309,14 +307,6 @@ static void print_mce(struct mce *m)
 		m->cpuvendor, m->cpuid, m->time, m->socketid, m->apicid,
 		cpu_data(m->extcpu).microcode);
 
-	/*
-	 * Print out human-readable details about the MCE error,
-	 * (if the CPU has an implementation for that)
-	 */
-	ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
-	if (ret == NOTIFY_STOP)
-		return;
-
 	pr_emerg_ratelimited(HW_ERR "Run the above through 'mcelog --ascii'\n");
 }
 

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#1630648 — [PATCH 4.9 03/21] KEYS: fix keyctl_set_reqkey_keyring() to not leak thread keyrings

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@google.com>

commit c9f838d104fed6f2f61d68164712e3204bf5271b upstream.

This fixes CVE-2017-7472.

Running the following program as an unprivileged user exhausts kernel
memory by leaking thread keyrings:

	#include <keyutils.h>

	int main()
	{
		for (;;)
			keyctl_set_reqkey_keyring(KEY_REQKEY_DEFL_THREAD_KEYRING);
	}

Fix it by only creating a new thread keyring if there wasn't one before.
To make things more consistent, make install_thread_keyring_to_cred()
and install_process_keyring_to_cred() both return 0 if the corresponding
keyring is already present.

Fixes: d84f4f992cbd ("CRED: Inaugurate COW credentials")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 security/keys/keyctl.c       |   11 +++-------
 security/keys/process_keys.c |   44 ++++++++++++++++++++++++++-----------------
 2 files changed, 31 insertions(+), 24 deletions(-)

--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1256,8 +1256,8 @@ error:
  * Read or set the default keyring in which request_key() will cache keys and
  * return the old setting.
  *
- * If a process keyring is specified then this will be created if it doesn't
- * yet exist.  The old setting will be returned if successful.
+ * If a thread or process keyring is specified then it will be created if it
+ * doesn't yet exist.  The old setting will be returned if successful.
  */
 long keyctl_set_reqkey_keyring(int reqkey_defl)
 {
@@ -1282,11 +1282,8 @@ long keyctl_set_reqkey_keyring(int reqke
 
 	case KEY_REQKEY_DEFL_PROCESS_KEYRING:
 		ret = install_process_keyring_to_cred(new);
-		if (ret < 0) {
-			if (ret != -EEXIST)
-				goto error;
-			ret = 0;
-		}
+		if (ret < 0)
+			goto error;
 		goto set;
 
 	case KEY_REQKEY_DEFL_DEFAULT:
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -127,13 +127,18 @@ error:
 }
 
 /*
- * Install a fresh thread keyring directly to new credentials.  This keyring is
- * allowed to overrun the quota.
+ * Install a thread keyring to the given credentials struct if it didn't have
+ * one already.  This is allowed to overrun the quota.
+ *
+ * Return: 0 if a thread keyring is now present; -errno on failure.
  */
 int install_thread_keyring_to_cred(struct cred *new)
 {
 	struct key *keyring;
 
+	if (new->thread_keyring)
+		return 0;
+
 	keyring = keyring_alloc("_tid", new->uid, new->gid, new,
 				KEY_POS_ALL | KEY_USR_VIEW,
 				KEY_ALLOC_QUOTA_OVERRUN,
@@ -146,7 +151,9 @@ int install_thread_keyring_to_cred(struc
 }
 
 /*
- * Install a fresh thread keyring, discarding the old one.
+ * Install a thread keyring to the current task if it didn't have one already.
+ *
+ * Return: 0 if a thread keyring is now present; -errno on failure.
  */
 static int install_thread_keyring(void)
 {
@@ -157,8 +164,6 @@ static int install_thread_keyring(void)
 	if (!new)
 		return -ENOMEM;
 
-	BUG_ON(new->thread_keyring);
-
 	ret = install_thread_keyring_to_cred(new);
 	if (ret < 0) {
 		abort_creds(new);
@@ -169,17 +174,17 @@ static int install_thread_keyring(void)
 }
 
 /*
- * Install a process keyring directly to a credentials struct.
+ * Install a process keyring to the given credentials struct if it didn't have
+ * one already.  This is allowed to overrun the quota.
  *
- * Returns -EEXIST if there was already a process keyring, 0 if one installed,
- * and other value on any other error
+ * Return: 0 if a process keyring is now present; -errno on failure.
  */
 int install_process_keyring_to_cred(struct cred *new)
 {
 	struct key *keyring;
 
 	if (new->process_keyring)
-		return -EEXIST;
+		return 0;
 
 	keyring = keyring_alloc("_pid", new->uid, new->gid, new,
 				KEY_POS_ALL | KEY_USR_VIEW,
@@ -193,11 +198,9 @@ int install_process_keyring_to_cred(stru
 }
 
 /*
- * Make sure a process keyring is installed for the current process.  The
- * existing process keyring is not replaced.
+ * Install a process keyring to the current task if it didn't have one already.
  *
- * Returns 0 if there is a process keyring by the end of this function, some
- * error otherwise.
+ * Return: 0 if a process keyring is now present; -errno on failure.
  */
 static int install_process_keyring(void)
 {
@@ -211,14 +214,18 @@ static int install_process_keyring(void)
 	ret = install_process_keyring_to_cred(new);
 	if (ret < 0) {
 		abort_creds(new);
-		return ret != -EEXIST ? ret : 0;
+		return ret;
 	}
 
 	return commit_creds(new);
 }
 
 /*
- * Install a session keyring directly to a credentials struct.
+ * Install the given keyring as the session keyring of the given credentials
+ * struct, replacing the existing one if any.  If the given keyring is NULL,
+ * then install a new anonymous session keyring.
+ *
+ * Return: 0 on success; -errno on failure.
  */
 int install_session_keyring_to_cred(struct cred *cred, struct key *keyring)
 {
@@ -253,8 +260,11 @@ int install_session_keyring_to_cred(stru
 }
 
 /*
- * Install a session keyring, discarding the old one.  If a keyring is not
- * supplied, an empty one is invented.
+ * Install the given keyring as the session keyring of the current task,
+ * replacing the existing one if any.  If the given keyring is NULL, then
+ * install a new anonymous session keyring.
+ *
+ * Return: 0 on success; -errno on failure.
  */
 static int install_session_keyring(struct key *keyring)
 {

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#1630651 — [PATCH 4.9 06/21] mm: prevent NR_ISOLATE_* stats from going negative

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Rabin Vincent <rabinv@axis.com>

commit fc280fe871449ead4bdbd1665fa52c7c01c64765 upstream.

Commit 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn
based migration") moved the dec_node_page_state() call (along with the
page_is_file_cache() call) to after putback_lru_page().

But page_is_file_cache() can change after putback_lru_page() is called,
so it should be called before putback_lru_page(), as it was before that
patch, to prevent NR_ISOLATE_* stats from going negative.

Without this fix, non-CONFIG_SMP kernels end up hanging in the
while(too_many_isolated()) { congestion_wait() } loop in
shrink_active_list() due to the negative stats.

 Mem-Info:
  active_anon:32567 inactive_anon:121 isolated_anon:1
  active_file:6066 inactive_file:6639 isolated_file:4294967295
                                                    ^^^^^^^^^^
  unevictable:0 dirty:115 writeback:0 unstable:0
  slab_reclaimable:2086 slab_unreclaimable:3167
  mapped:3398 shmem:18366 pagetables:1145 bounce:0
  free:1798 free_pcp:13 free_cma:0

Fixes: 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration")
Link: http://lkml.kernel.org/r/1492683865-27549-1-git-send-email-rabin.vincent@axis.com
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Ming Ling <ming.ling@spreadtrum.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/migrate.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -183,9 +183,9 @@ void putback_movable_pages(struct list_h
 			unlock_page(page);
 			put_page(page);
 		} else {
-			putback_lru_page(page);
 			dec_node_page_state(page, NR_ISOLATED_ANON +
 					page_is_file_cache(page));
+			putback_lru_page(page);
 		}
 	}
 }

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#1630652 — [PATCH 4.9 14/21] ubifs: Fix O_TMPFILE corner case in ubifs_link()

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Richard Weinberger <richard@nod.at>

commit 32fe905c17f001c0eee13c59afddd0bf2eed509c upstream.

It is perfectly fine to link a tmpfile back using linkat().
Since tmpfiles are created with a link count of 0 they appear
on the orphan list, upon re-linking the inode has to be removed
from the orphan list again.

Ralph faced a filesystem corruption in combination with overlayfs
due to this bug.

Cc: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Reported-by: Amir Goldstein <amir73il@gmail.com>
Fixes: 474b93704f321 ("ubifs: Implement O_TMPFILE")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/ubifs/dir.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -622,6 +622,11 @@ static int ubifs_link(struct dentry *old
 		return err;
 
 	lock_2_inodes(dir, inode);
+
+	/* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
+	if (inode->i_nlink == 0)
+		ubifs_delete_orphan(c, inode->i_ino);
+
 	inc_nlink(inode);
 	ihold(inode);
 	inode->i_ctime = ubifs_current_time(inode);
@@ -641,6 +646,8 @@ out_cancel:
 	dir->i_size -= sz_change;
 	dir_ui->ui_size = dir->i_size;
 	drop_nlink(inode);
+	if (inode->i_nlink == 0)
+		ubifs_add_orphan(c, inode->i_ino);
 	unlock_2_inodes(dir, inode);
 	ubifs_release_budget(c, &req);
 	iput(inode);

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#1630653 — [PATCH 4.9 19/21] x86/mce/AMD: Give a name to MCA bank 3 when accessed with legacy MSRs

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yazen Ghannam <yazen.ghannam@amd.com>

commit 29f72ce3e4d18066ec75c79c857bee0618a3504b upstream.

MCA bank 3 is reserved on systems pre-Fam17h, so it didn't have a name.
However, MCA bank 3 is defined on Fam17h systems and can be accessed
using legacy MSRs. Without a name we get a stack trace on Fam17h systems
when trying to register sysfs files for bank 3 on kernels that don't
recognize Scalable MCA.

Call MCA bank 3 "decode_unit" since this is what it represents on
Fam17h. This will allow kernels without SMCA support to see this bank on
Fam17h+ and prevent the stack trace. This will not affect older systems
since this bank is reserved on them, i.e. it'll be ignored.

Tested on AMD Fam15h and Fam17h systems.

  WARNING: CPU: 26 PID: 1 at lib/kobject.c:210 kobject_add_internal
  kobject: (ffff88085bb256c0): attempted to be registered with empty name!
  ...
  Call Trace:
   kobject_add_internal
   kobject_add
   kobject_create_and_add
   threshold_create_device
   threshold_init_device

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1490102285-3659-1-git-send-email-Yazen.Ghannam@amd.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/cpu/mcheck/mce_amd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -59,7 +59,7 @@ static const char * const th_names[] = {
 	"load_store",
 	"insn_fetch",
 	"combined_unit",
-	"",
+	"decode_unit",
 	"northbridge",
 	"execution_unit",
 };

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#1630655 — [PATCH 4.9 18/21] powerpc/kprobe: Fix oops when kprobed on stdu instruction

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>

commit 9e1ba4f27f018742a1aa95d11e35106feba08ec1 upstream.

If we set a kprobe on a 'stdu' instruction on powerpc64, we see a kernel
OOPS:

  Bad kernel stack pointer cd93c840 at c000000000009868
  Oops: Bad kernel stack pointer, sig: 6 [#1]
  ...
  GPR00: c000001fcd93cb30 00000000cd93c840 c0000000015c5e00 00000000cd93c840
  ...
  NIP [c000000000009868] resume_kernel+0x2c/0x58
  LR [c000000000006208] program_check_common+0x108/0x180

On a 64-bit system when the user probes on a 'stdu' instruction, the kernel does
not emulate actual store in emulate_step() because it may corrupt the exception
frame. So the kernel does the actual store operation in exception return code
i.e. resume_kernel().

resume_kernel() loads the saved stack pointer from memory using lwz, which only
loads the low 32-bits of the address, causing the kernel crash.

Fix this by loading the 64-bit value instead.

Fixes: be96f63375a1 ("powerpc: Split out instruction analysis part of emulate_step()")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
[mpe: Change log massage, add stable tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/entry_64.S |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -689,7 +689,7 @@ resume_kernel:
 
 	addi	r8,r1,INT_FRAME_SIZE	/* Get the kprobed function entry */
 
-	lwz	r3,GPR1(r1)
+	ld	r3,GPR1(r1)
 	subi	r3,r3,INT_FRAME_SIZE	/* dst: Allocate a trampoline exception frame */
 	mr	r4,r1			/* src:  current exception frame */
 	mr	r1,r3			/* Reroute the trampoline frame to r1 */
@@ -703,8 +703,8 @@ resume_kernel:
 	addi	r6,r6,8
 	bdnz	2b
 
-	/* Do real store operation to complete stwu */
-	lwz	r5,GPR1(r1)
+	/* Do real store operation to complete stdu */
+	ld	r5,GPR1(r1)
 	std	r8,0(r5)
 
 	/* Clear _TIF_EMULATE_STACK_STORE flag */

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#1630660 — [PATCH 4.9 13/21] ubifs: Fix RENAME_WHITEOUT support

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felix Fietkau <nbd@nbd.name>

commit c3d9fda688742c06e89aa1f0f8fd943fc11468cb upstream.

Remove faulty leftover check in do_rename(), apparently introduced in a
merge that combined whiteout support changes with commit f03b8ad8d386
("fs: support RENAME_NOREPLACE for local filesystems")

Fixes: f03b8ad8d386 ("fs: support RENAME_NOREPLACE for local filesystems")
Fixes: 9e0a1fff8db5 ("ubifs: Implement RENAME_WHITEOUT")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/ubifs/dir.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1088,9 +1088,6 @@ static int do_rename(struct inode *old_d
 	struct timespec time;
 	unsigned int uninitialized_var(saved_nlink);
 
-	if (flags & ~RENAME_NOREPLACE)
-		return -EINVAL;
-
 	/*
 	 * Budget request settings: deletion direntry, new direntry, removing
 	 * the old inode, and changing old and new parent directory inodes.

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#1630664 — [PATCH 4.9 17/21] ubi/upd: Always flush after prepared for an update

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sebastian Siewior <bigeasy@linutronix.de>

commit 9cd9a21ce070be8a918ffd3381468315a7a76ba6 upstream.

In commit 6afaf8a484cb ("UBI: flush wl before clearing update marker") I
managed to trigger and fix a similar bug. Now here is another version of
which I assumed it wouldn't matter back then but it turns out UBI has a
check for it and will error out like this:

|ubi0 warning: validate_vid_hdr: inconsistent used_ebs
|ubi0 error: validate_vid_hdr: inconsistent VID header at PEB 592

All you need to trigger this is? "ubiupdatevol /dev/ubi0_0 file" + a
powercut in the middle of the operation.
ubi_start_update() sets the update-marker and puts all EBs on the erase
list. After that userland can proceed to write new data while the old EB
aren't erased completely. A powercut at this point is usually not that
much of a tragedy. UBI won't give read access to the static volume
because it has the update marker. It will most likely set the corrupted
flag because it misses some EBs.
So we are all good. Unless the size of the image that has been written
differs from the old image in the magnitude of at least one EB. In that
case UBI will find two different values for `used_ebs' and refuse to
attach the image with the error message mentioned above.

So in order not to get in the situation, the patch will ensure that we
wait until everything is removed before it tries to write any data.
The alternative would be to detect such a case and remove all EBs at the
attached time after we processed the volume-table and see the
update-marker set. The patch looks bigger and I doubt it is worth it
since usually the write() will wait from time to time for a new EB since
usually there not that many spare EB that can be used.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mtd/ubi/upd.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/mtd/ubi/upd.c
+++ b/drivers/mtd/ubi/upd.c
@@ -148,11 +148,11 @@ int ubi_start_update(struct ubi_device *
 			return err;
 	}
 
-	if (bytes == 0) {
-		err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
-		if (err)
-			return err;
+	err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
+	if (err)
+		return err;
 
+	if (bytes == 0) {
 		err = clear_update_marker(ubi, vol, 0);
 		if (err)
 			return err;

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#1630665 — [PATCH 4.9 07/21] cifs: Do not send echoes before Negotiate is complete

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sachin Prabhu <sprabhu@redhat.com>

commit 62a6cfddcc0a5313e7da3e8311ba16226fe0ac10 upstream.

commit 4fcd1813e640 ("Fix reconnect to not defer smb3 session reconnect
long after socket reconnect") added support for Negotiate requests to
be initiated by echo calls.

To avoid delays in calling echo after a reconnect, I added the patch
introduced by the commit b8c600120fc8 ("Call echo service immediately
after socket reconnect").

This has however caused a regression with cifs shares which do not have
support for echo calls to trigger Negotiate requests. On connections
which need to call Negotiation, the echo calls trigger an error which
triggers a reconnect which in turn triggers another echo call. This
results in a loop which is only broken when an operation is performed on
the cifs share. For an idle share, it can DOS a server.

The patch uses the smb_operation can_echo() for cifs so that it is
called only if connection has been already been setup.

kernel bz: 194531

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Tested-by: Jonathan Liu <net147@gmail.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/cifs/smb1ops.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -1015,6 +1015,15 @@ cifs_dir_needs_close(struct cifsFileInfo
 	return !cfile->srch_inf.endOfSearch && !cfile->invalidHandle;
 }
 
+static bool
+cifs_can_echo(struct TCP_Server_Info *server)
+{
+	if (server->tcpStatus == CifsGood)
+		return true;
+
+	return false;
+}
+
 struct smb_version_operations smb1_operations = {
 	.send_cancel = send_nt_cancel,
 	.compare_fids = cifs_compare_fids,
@@ -1049,6 +1058,7 @@ struct smb_version_operations smb1_opera
 	.get_dfs_refer = CIFSGetDFSRefer,
 	.qfs_tcon = cifs_qfs_tcon,
 	.is_path_accessible = cifs_is_path_accessible,
+	.can_echo = cifs_can_echo,
 	.query_path_info = cifs_query_path_info,
 	.query_file_info = cifs_query_file_info,
 	.get_srv_inum = cifs_get_srv_inum,

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#1630670 — [PATCH 4.9 02/21] KEYS: Change the name of the dead type to ".dead" to prevent user access

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

commit c1644fe041ebaf6519f6809146a77c3ead9193af upstream.

This fixes CVE-2017-6951.

Userspace should not be able to do things with the "dead" key type as it
doesn't have some of the helper functions set upon it that the kernel
needs.  Attempting to use it may cause the kernel to crash.

Fix this by changing the name of the type to ".dead" so that it's rejected
up front on userspace syscalls by key_get_type_from_user().

Though this doesn't seem to affect recent kernels, it does affect older
ones, certainly those prior to:

	commit c06cfb08b88dfbe13be44a69ae2fdc3a7c902d81
	Author: David Howells <dhowells@redhat.com>
	Date:   Tue Sep 16 17:36:06 2014 +0100
	KEYS: Remove key_type::match in favour of overriding default by match_preparse

which went in before 3.18-rc1.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 security/keys/gc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -46,7 +46,7 @@ static unsigned long key_gc_flags;
  * immediately unlinked.
  */
 struct key_type key_type_dead = {
-	.name = "dead",
+	.name = ".dead",
 };
 
 /*

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#1630675 — [PATCH 4.9 21/21] device-dax: switch to srcu, fix rcu_read_lock() vs pte allocation

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams <dan.j.williams@intel.com>

commit 956a4cd2c957acf638ff29951aabaa9d8e92bbc2 upstream.

The following warning triggers with a new unit test that stresses the
device-dax interface.

 ===============================
 [ ERR: suspicious RCU usage.  ]
 4.11.0-rc4+ #1049 Tainted: G           O
 -------------------------------
 ./include/linux/rcupdate.h:521 Illegal context switch in RCU read-side critical section!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 0
 2 locks held by fio/9070:
  #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff8d0739d7>] __do_page_fault+0x167/0x4f0
  #1:  (rcu_read_lock){......}, at: [<ffffffffc03fbd02>] dax_dev_huge_fault+0x32/0x620 [dax]

 Call Trace:
  dump_stack+0x86/0xc3
  lockdep_rcu_suspicious+0xd7/0x110
  ___might_sleep+0xac/0x250
  __might_sleep+0x4a/0x80
  __alloc_pages_nodemask+0x23a/0x360
  alloc_pages_current+0xa1/0x1f0
  pte_alloc_one+0x17/0x80
  __pte_alloc+0x1e/0x120
  __get_locked_pte+0x1bf/0x1d0
  insert_pfn.isra.70+0x3a/0x100
  ? lookup_memtype+0xa6/0xd0
  vm_insert_mixed+0x64/0x90
  dax_dev_huge_fault+0x520/0x620 [dax]
  ? dax_dev_huge_fault+0x32/0x620 [dax]
  dax_dev_fault+0x10/0x20 [dax]
  __do_fault+0x1e/0x140
  __handle_mm_fault+0x9af/0x10d0
  handle_mm_fault+0x16d/0x370
  ? handle_mm_fault+0x47/0x370
  __do_page_fault+0x28c/0x4f0
  trace_do_page_fault+0x58/0x2a0
  do_async_page_fault+0x1a/0xa0
  async_page_fault+0x28/0x30

Inserting a page table entry may trigger an allocation while we are
holding a read lock to keep the device instance alive for the duration
of the fault. Use srcu for this keep-alive protection.

Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/dax/Kconfig |    1 +
 drivers/dax/dax.c   |   13 +++++++------
 2 files changed, 8 insertions(+), 6 deletions(-)

--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -2,6 +2,7 @@ menuconfig DEV_DAX
 	tristate "DAX: direct access to differentiated memory"
 	default m if NVDIMM_DAX
 	depends on TRANSPARENT_HUGEPAGE
+	select SRCU
 	help
 	  Support raw access to differentiated (persistence, bandwidth,
 	  latency...) memory via an mmap(2) capable character
--- a/drivers/dax/dax.c
+++ b/drivers/dax/dax.c
@@ -24,6 +24,7 @@
 #include "dax.h"
 
 static dev_t dax_devt;
+DEFINE_STATIC_SRCU(dax_srcu);
 static struct class *dax_class;
 static DEFINE_IDA(dax_minor_ida);
 static int nr_dax = CONFIG_NR_DEV_DAX;
@@ -59,7 +60,7 @@ struct dax_region {
  * @region - parent region
  * @dev - device backing the character device
  * @cdev - core chardev data
- * @alive - !alive + rcu grace period == no new mappings can be established
+ * @alive - !alive + srcu grace period == no new mappings can be established
  * @id - child id in the region
  * @num_resources - number of physical address extents in this device
  * @res - array of physical address ranges
@@ -437,7 +438,7 @@ static int __dax_dev_pmd_fault(struct da
 static int dax_dev_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 		pmd_t *pmd, unsigned int flags)
 {
-	int rc;
+	int rc, id;
 	struct file *filp = vma->vm_file;
 	struct dax_dev *dax_dev = filp->private_data;
 
@@ -445,9 +446,9 @@ static int dax_dev_pmd_fault(struct vm_a
 			current->comm, (flags & FAULT_FLAG_WRITE)
 			? "write" : "read", vma->vm_start, vma->vm_end);
 
-	rcu_read_lock();
+	id = srcu_read_lock(&dax_srcu);
 	rc = __dax_dev_pmd_fault(dax_dev, vma, addr, pmd, flags);
-	rcu_read_unlock();
+	srcu_read_unlock(&dax_srcu, id);
 
 	return rc;
 }
@@ -563,11 +564,11 @@ static void unregister_dax_dev(void *dev
 	 * Note, rcu is not protecting the liveness of dax_dev, rcu is
 	 * ensuring that any fault handlers that might have seen
 	 * dax_dev->alive == true, have completed.  Any fault handlers
-	 * that start after synchronize_rcu() has started will abort
+	 * that start after synchronize_srcu() has started will abort
 	 * upon seeing dax_dev->alive == false.
 	 */
 	dax_dev->alive = false;
-	synchronize_rcu();
+	synchronize_srcu(&dax_srcu);
 	unmap_mapping_range(dax_dev->inode->i_mapping, 0, 0, 1);
 	cdev_del(cdev);
 	device_unregister(dev);

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#1630683 — [PATCH 4.9 01/21] KEYS: Disallow keyrings beginning with . to be joined as session keyrings

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@redhat.com>

commit ee8f844e3c5a73b999edf733df1c529d6503ec2f upstream.

This fixes CVE-2016-9604.

Keyrings whose name begin with a '.' are special internal keyrings and so
userspace isn't allowed to create keyrings by this name to prevent
shadowing.  However, the patch that added the guard didn't fix
KEYCTL_JOIN_SESSION_KEYRING.  Not only can that create dot-named keyrings,
it can also subscribe to them as a session keyring if they grant SEARCH
permission to the user.

This, for example, allows a root process to set .builtin_trusted_keys as
its session keyring, at which point it has full access because now the
possessor permissions are added.  This permits root to add extra public
keys, thereby bypassing module verification.

This also affects kexec and IMA.

This can be tested by (as root):

	keyctl session .builtin_trusted_keys
	keyctl add user a a @s
	keyctl list @s

which on my test box gives me:

	2 keys in keyring:
	180010936: ---lswrv     0     0 asymmetric: Build time autogenerated kernel key: ae3d4a31b82daa8e1a75b49dc2bba949fd992a05
	801382539: --alswrv     0     0 user: a


Fix this by rejecting names beginning with a '.' in the keyctl.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
cc: linux-ima-devel@lists.sourceforge.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 security/keys/keyctl.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -271,7 +271,8 @@ error:
  * Create and join an anonymous session keyring or join a named session
  * keyring, creating it if necessary.  A named session keyring must have Search
  * permission for it to be joined.  Session keyrings without this permit will
- * be skipped over.
+ * be skipped over.  It is not permitted for userspace to create or join
+ * keyrings whose name begin with a dot.
  *
  * If successful, the ID of the joined session keyring will be returned.
  */
@@ -288,12 +289,16 @@ long keyctl_join_session_keyring(const c
 			ret = PTR_ERR(name);
 			goto error;
 		}
+
+		ret = -EPERM;
+		if (name[0] == '.')
+			goto error_name;
 	}
 
 	/* join the session */
 	ret = join_session_keyring(name);
+error_name:
 	kfree(name);
-
 error:
 	return ret;
 }

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#1630685 — [PATCH 4.9 10/21] Input: elantech - add Fujitsu Lifebook E547 to force crc_enabled

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thorsten Leemhuis <linux@leemhuis.info>

commit 704de489e0e3640a2ee2d0daf173e9f7375582ba upstream.

Temporary got a Lifebook E547 into my hands and noticed the touchpad
only works after running:

	echo "1" > /sys/devices/platform/i8042/serio2/crc_enabled

Add it to the list of machines that need this workaround.

Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Reviewed-by: Ulrik De Bie <ulrik.debie-os@e2big.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/input/mouse/elantech.c |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -1118,6 +1118,7 @@ static int elantech_get_resolution_v4(st
  * Asus UX32VD             0x361f02        00, 15, 0e      clickpad
  * Avatar AVIU-145A2       0x361f00        ?               clickpad
  * Fujitsu LIFEBOOK E544   0x470f00        d0, 12, 09      2 hw buttons
+ * Fujitsu LIFEBOOK E547   0x470f00        50, 12, 09      2 hw buttons
  * Fujitsu LIFEBOOK E554   0x570f01        40, 14, 0c      2 hw buttons
  * Fujitsu T725            0x470f01        05, 12, 09      2 hw buttons
  * Fujitsu H730            0x570f00        c0, 14, 0c      3 hw buttons (**)
@@ -1524,6 +1525,13 @@ static const struct dmi_system_id elante
 		},
 	},
 	{
+		/* Fujitsu LIFEBOOK E547 does not work with crc_enabled == 0 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E547"),
+		},
+	},
+	{
 		/* Fujitsu LIFEBOOK E554  does not work with crc_enabled == 0 */
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),

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#1630870

On 04/25/2017 09:08 AM, Greg Kroah-Hartman wrote:
> This is the start of the stable review cycle for the 4.9.25 release.
> There are 21 patches in this series, all will be posted as a response
> to this one.  If anyone has any issues with these being applied, please
> let me know.
> 
> Responses should be made by Thu Apr 27 15:08:14 UTC 2017.
> Anything received after that time might be too late.
> 
> The whole patch series can be found in one patch at:
> 	kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.25-rc1.gz
> or in the git tree and branch at:
>   git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.9.y
> and the diffstat can be found below.
> 
> thanks,
> 
> greg k-h
> 

Compiled and booted on my test system. No dmesg regressions.

thanks,
-- Shuah

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#1631112

On 04/25/2017 08:08 AM, Greg Kroah-Hartman wrote:
> This is the start of the stable review cycle for the 4.9.25 release.
> There are 21 patches in this series, all will be posted as a response
> to this one.  If anyone has any issues with these being applied, please
> let me know.
>
> Responses should be made by Thu Apr 27 15:08:14 UTC 2017.
> Anything received after that time might be too late.
>

Build results:
	total: 149 pass: 149 fail: 0
Qemu test results:
	total: 122 pass: 122 fail: 0

Details are available at http://kerneltests.org/builders.

Guenter

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