Merge 4.4.123 into android-4.4

Changes in 4.4.123
	blkcg: fix double free of new_blkg in blkcg_init_queue
	Input: tsc2007 - check for presence and power down tsc2007 during probe
	staging: speakup: Replace BUG_ON() with WARN_ON().
	staging: wilc1000: add check for kmalloc allocation failure.
	HID: reject input outside logical range only if null state is set
	drm: qxl: Don't alloc fbdev if emulation is not supported
	ath10k: fix a warning during channel switch with multiple vaps
	PCI/MSI: Stop disabling MSI/MSI-X in pci_device_shutdown()
	selinux: check for address length in selinux_socket_bind()
	perf sort: Fix segfault with basic block 'cycles' sort dimension
	i40e: Acquire NVM lock before reads on all devices
	i40e: fix ethtool to get EEPROM data from X722 interface
	perf tools: Make perf_event__synthesize_mmap_events() scale
	drivers: net: xgene: Fix hardware checksum setting
	drm: Defer disabling the vblank IRQ until the next interrupt (for instant-off)
	ath10k: disallow DFS simulation if DFS channel is not enabled
	perf probe: Return errno when not hitting any event
	HID: clamp input to logical range if no null state
	net/8021q: create device with all possible features in wanted_features
	ARM: dts: Adjust moxart IRQ controller and flags
	batman-adv: handle race condition for claims between gateways
	of: fix of_device_get_modalias returned length when truncating buffers
	solo6x10: release vb2 buffers in solo_stop_streaming()
	scsi: ipr: Fix missed EH wakeup
	media: i2c/soc_camera: fix ov6650 sensor getting wrong clock
	timers, sched_clock: Update timeout for clock wrap
	sysrq: Reset the watchdog timers while displaying high-resolution timers
	Input: qt1070 - add OF device ID table
	sched: act_csum: don't mangle TCP and UDP GSO packets
	ASoC: rcar: ssi: don't set SSICR.CKDV = 000 with SSIWSR.CONT
	spi: omap2-mcspi: poll OMAP2_MCSPI_CHSTAT_RXS for PIO transfer
	tcp: sysctl: Fix a race to avoid unexpected 0 window from space
	dmaengine: imx-sdma: add 1ms delay to ensure SDMA channel is stopped
	driver: (adm1275) set the m,b and R coefficients correctly for power
	mm: Fix false-positive VM_BUG_ON() in page_cache_{get,add}_speculative()
	blk-throttle: make sure expire time isn't too big
	f2fs: relax node version check for victim data in gc
	bonding: refine bond_fold_stats() wrap detection
	braille-console: Fix value returned by _braille_console_setup
	drm/vmwgfx: Fixes to vmwgfx_fb
	vxlan: vxlan dev should inherit lowerdev's gso_max_size
	NFC: nfcmrvl: Include unaligned.h instead of access_ok.h
	NFC: nfcmrvl: double free on error path
	ARM: dts: r8a7790: Correct parent of SSI[0-9] clocks
	ARM: dts: r8a7791: Correct parent of SSI[0-9] clocks
	powerpc: Avoid taking a data miss on every userspace instruction miss
	net/faraday: Add missing include of of.h
	ARM: dts: koelsch: Correct clock frequency of X2 DU clock input
	reiserfs: Make cancel_old_flush() reliable
	ALSA: firewire-digi00x: handle all MIDI messages on streaming packets
	fm10k: correctly check if interface is removed
	scsi: ses: don't get power status of SES device slot on probe
	apparmor: Make path_max parameter readonly
	iommu/iova: Fix underflow bug in __alloc_and_insert_iova_range
	video: ARM CLCD: fix dma allocation size
	drm/radeon: Fail fb creation from imported dma-bufs.
	drm/amdgpu: Fail fb creation from imported dma-bufs. (v2)
	coresight: Fixes coresight DT parse to get correct output port ID.
	MIPS: BPF: Quit clobbering callee saved registers in JIT code.
	MIPS: BPF: Fix multiple problems in JIT skb access helpers.
	MIPS: r2-on-r6-emu: Fix BLEZL and BGTZL identification
	MIPS: r2-on-r6-emu: Clear BLTZALL and BGEZALL debugfs counters
	regulator: isl9305: fix array size
	md/raid6: Fix anomily when recovering a single device in RAID6.
	usb: dwc2: Make sure we disconnect the gadget state
	usb: gadget: dummy_hcd: Fix wrong power status bit clear/reset in dummy_hub_control()
	drivers/perf: arm_pmu: handle no platform_device
	perf inject: Copy events when reordering events in pipe mode
	perf session: Don't rely on evlist in pipe mode
	scsi: sg: check for valid direction before starting the request
	scsi: sg: close race condition in sg_remove_sfp_usercontext()
	kprobes/x86: Fix kprobe-booster not to boost far call instructions
	kprobes/x86: Set kprobes pages read-only
	pwm: tegra: Increase precision in PWM rate calculation
	wil6210: fix memory access violation in wil_memcpy_from/toio_32
	drm/edid: set ELD connector type in drm_edid_to_eld()
	video/hdmi: Allow "empty" HDMI infoframes
	HID: elo: clear BTN_LEFT mapping
	ARM: dts: exynos: Correct Trats2 panel reset line
	sched: Stop switched_to_rt() from sending IPIs to offline CPUs
	sched: Stop resched_cpu() from sending IPIs to offline CPUs
	test_firmware: fix setting old custom fw path back on exit
	net: xfrm: allow clearing socket xfrm policies.
	mtd: nand: fix interpretation of NAND_CMD_NONE in nand_command[_lp]()
	ARM: dts: am335x-pepper: Fix the audio CODEC's reset pin
	ARM: dts: omap3-n900: Fix the audio CODEC's reset pin
	ath10k: update tdls teardown state to target
	cpufreq: Fix governor module removal race
	clk: qcom: msm8916: fix mnd_width for codec_digcodec
	ath10k: fix invalid STS_CAP_OFFSET_MASK
	tools/usbip: fixes build with musl libc toolchain
	spi: sun6i: disable/unprepare clocks on remove
	scsi: core: scsi_get_device_flags_keyed(): Always return device flags
	scsi: devinfo: apply to HP XP the same flags as Hitachi VSP
	scsi: dh: add new rdac devices
	media: cpia2: Fix a couple off by one bugs
	veth: set peer GSO values
	drm/amdkfd: Fix memory leaks in kfd topology
	agp/intel: Flush all chipset writes after updating the GGTT
	mac80211_hwsim: enforce PS_MANUAL_POLL to be set after PS_ENABLED
	mac80211: remove BUG() when interface type is invalid
	ASoC: nuc900: Fix a loop timeout test
	ipvlan: add L2 check for packets arriving via virtual devices
	rcutorture/configinit: Fix build directory error message
	ima: relax requiring a file signature for new files with zero length
	selftests/x86/entry_from_vm86: Exit with 1 if we fail
	selftests/x86: Add tests for User-Mode Instruction Prevention
	selftests/x86: Add tests for the STR and SLDT instructions
	selftests/x86/entry_from_vm86: Add test cases for POPF
	x86/vm86/32: Fix POPF emulation
	x86/mm: Fix vmalloc_fault to use pXd_large
	ALSA: pcm: Fix UAF in snd_pcm_oss_get_formats()
	ALSA: hda - Revert power_save option default value
	ALSA: seq: Fix possible UAF in snd_seq_check_queue()
	ALSA: seq: Clear client entry before deleting else at closing
	drm/amdgpu/dce: Don't turn off DP sink when disconnected
	fs: Teach path_connected to handle nfs filesystems with multiple roots.
	lock_parent() needs to recheck if dentry got __dentry_kill'ed under it
	fs/aio: Add explicit RCU grace period when freeing kioctx
	fs/aio: Use RCU accessors for kioctx_table->table[]
	irqchip/gic-v3-its: Ensure nr_ites >= nr_lpis
	scsi: sg: fix SG_DXFER_FROM_DEV transfers
	scsi: sg: fix static checker warning in sg_is_valid_dxfer
	scsi: sg: only check for dxfer_len greater than 256M
	ARM: dts: LogicPD Torpedo: Fix I2C1 pinmux
	btrfs: alloc_chunk: fix DUP stripe size handling
	btrfs: Fix use-after-free when cleaning up fs_devs with a single stale device
	USB: gadget: udc: Add missing platform_device_put() on error in bdc_pci_probe()
	usb: gadget: bdc: 64-bit pointer capability check
	bpf: fix incorrect sign extension in check_alu_op()
	Linux 4.4.123

Change-Id: Ieb89411248f93522dde29edb8581f8ece22e33a7
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 30 insertions, 14 deletions

diff --git a/fs/aio.c b/fs/aio.c
index fe4f49212b99..88ede4a84ce0 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -68,9 +68,9 @@ struct aio_ring {
 #define AIO_RING_PAGES	8
 
 struct kioctx_table {
-	struct rcu_head	rcu;
-	unsigned	nr;
-	struct kioctx	*table[];
+	struct rcu_head		rcu;
+	unsigned		nr;
+	struct kioctx __rcu	*table[];
 };
 
 struct kioctx_cpu {
@@ -115,7 +115,8 @@ struct kioctx {
 	struct page		**ring_pages;
 	long			nr_pages;
 
-	struct work_struct	free_work;
+	struct rcu_head		free_rcu;
+	struct work_struct	free_work;	/* see free_ioctx() */
 
 	/*
 	 * signals when all in-flight requests are done
@@ -326,7 +327,7 @@ static int aio_ring_mremap(struct vm_area_struct *vma)
 	for (i = 0; i < table->nr; i++) {
 		struct kioctx *ctx;
 
-		ctx = table->table[i];
+		ctx = rcu_dereference(table->table[i]);
 		if (ctx && ctx->aio_ring_file == file) {
 			if (!atomic_read(&ctx->dead)) {
 				ctx->user_id = ctx->mmap_base = vma->vm_start;
@@ -573,6 +574,12 @@ static int kiocb_cancel(struct aio_kiocb *kiocb)
 	return cancel(&kiocb->common);
 }
 
+/*
+ * free_ioctx() should be RCU delayed to synchronize against the RCU
+ * protected lookup_ioctx() and also needs process context to call
+ * aio_free_ring(), so the double bouncing through kioctx->free_rcu and
+ * ->free_work.
+ */
 static void free_ioctx(struct work_struct *work)
 {
 	struct kioctx *ctx = container_of(work, struct kioctx, free_work);
@@ -586,6 +593,14 @@ static void free_ioctx(struct work_struct *work)
 	kmem_cache_free(kioctx_cachep, ctx);
 }
 
+static void free_ioctx_rcufn(struct rcu_head *head)
+{
+	struct kioctx *ctx = container_of(head, struct kioctx, free_rcu);
+
+	INIT_WORK(&ctx->free_work, free_ioctx);
+	schedule_work(&ctx->free_work);
+}
+
 static void free_ioctx_reqs(struct percpu_ref *ref)
 {
 	struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
@@ -594,8 +609,8 @@ static void free_ioctx_reqs(struct percpu_ref *ref)
 	if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
 		complete(&ctx->rq_wait->comp);
 
-	INIT_WORK(&ctx->free_work, free_ioctx);
-	schedule_work(&ctx->free_work);
+	/* Synchronize against RCU protected table->table[] dereferences */
+	call_rcu(&ctx->free_rcu, free_ioctx_rcufn);
 }
 
 /*
@@ -636,9 +651,9 @@ static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
 	while (1) {
 		if (table)
 			for (i = 0; i < table->nr; i++)
-				if (!table->table[i]) {
+				if (!rcu_access_pointer(table->table[i])) {
 					ctx->id = i;
-					table->table[i] = ctx;
+					rcu_assign_pointer(table->table[i], ctx);
 					spin_unlock(&mm->ioctx_lock);
 
 					/* While kioctx setup is in progress,
@@ -813,11 +828,11 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
 	}
 
 	table = rcu_dereference_raw(mm->ioctx_table);
-	WARN_ON(ctx != table->table[ctx->id]);
-	table->table[ctx->id] = NULL;
+	WARN_ON(ctx != rcu_access_pointer(table->table[ctx->id]));
+	RCU_INIT_POINTER(table->table[ctx->id], NULL);
 	spin_unlock(&mm->ioctx_lock);
 
-	/* percpu_ref_kill() will do the necessary call_rcu() */
+	/* free_ioctx_reqs() will do the necessary RCU synchronization */
 	wake_up_all(&ctx->wait);
 
 	/*
@@ -859,7 +874,8 @@ void exit_aio(struct mm_struct *mm)
 
 	skipped = 0;
 	for (i = 0; i < table->nr; ++i) {
-		struct kioctx *ctx = table->table[i];
+		struct kioctx *ctx =
+			rcu_dereference_protected(table->table[i], true);
 
 		if (!ctx) {
 			skipped++;
@@ -1048,7 +1064,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
 	if (!table || id >= table->nr)
 		goto out;
 
-	ctx = table->table[id];
+	ctx = rcu_dereference(table->table[id]);
 	if (ctx && ctx->user_id == ctx_id) {
 		percpu_ref_get(&ctx->users);
 		ret = ctx;