Merge 4.4.168 into android-4.4-p

Changes in 4.4.168
	ipv6: Check available headroom in ip6_xmit() even without options
	net: 8139cp: fix a BUG triggered by changing mtu with network traffic
	net: phy: don't allow __set_phy_supported to add unsupported modes
	net: Prevent invalid access to skb->prev in __qdisc_drop_all
	rtnetlink: ndo_dflt_fdb_dump() only work for ARPHRD_ETHER devices
	tcp: fix NULL ref in tail loss probe
	tun: forbid iface creation with rtnl ops
	neighbour: Avoid writing before skb->head in neigh_hh_output()
	ARM: OMAP2+: prm44xx: Fix section annotation on omap44xx_prm_enable_io_wakeup
	ARM: OMAP1: ams-delta: Fix possible use of uninitialized field
	sysv: return 'err' instead of 0 in __sysv_write_inode
	s390/cpum_cf: Reject request for sampling in event initialization
	hwmon: (ina2xx) Fix current value calculation
	ASoC: dapm: Recalculate audio map forcely when card instantiated
	hwmon: (w83795) temp4_type has writable permission
	Btrfs: send, fix infinite loop due to directory rename dependencies
	ASoC: omap-mcpdm: Add pm_qos handling to avoid under/overruns with CPU_IDLE
	ASoC: omap-dmic: Add pm_qos handling to avoid overruns with CPU_IDLE
	exportfs: do not read dentry after free
	bpf: fix check of allowed specifiers in bpf_trace_printk
	USB: omap_udc: use devm_request_irq()
	USB: omap_udc: fix crashes on probe error and module removal
	USB: omap_udc: fix omap_udc_start() on 15xx machines
	USB: omap_udc: fix USB gadget functionality on Palm Tungsten E
	KVM: x86: fix empty-body warnings
	net: thunderx: fix NULL pointer dereference in nic_remove
	ixgbe: recognize 1000BaseLX SFP modules as 1Gbps
	net: hisilicon: remove unexpected free_netdev
	drm/ast: fixed reading monitor EDID not stable issue
	xen: xlate_mmu: add missing header to fix 'W=1' warning
	fscache: fix race between enablement and dropping of object
	fscache, cachefiles: remove redundant variable 'cache'
	ocfs2: fix deadlock caused by ocfs2_defrag_extent()
	hfs: do not free node before using
	hfsplus: do not free node before using
	debugobjects: avoid recursive calls with kmemleak
	ocfs2: fix potential use after free
	pstore: Convert console write to use ->write_buf
	ALSA: pcm: remove SNDRV_PCM_IOCTL1_INFO internal command
	KVM: nVMX: fix msr bitmaps to prevent L2 from accessing L0 x2APIC
	KVM: nVMX: mark vmcs12 pages dirty on L2 exit
	KVM: nVMX: Eliminate vmcs02 pool
	KVM: VMX: introduce alloc_loaded_vmcs
	KVM: VMX: make MSR bitmaps per-VCPU
	KVM/x86: Add IBPB support
	KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
	KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL
	KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL
	KVM/x86: Remove indirect MSR op calls from SPEC_CTRL
	x86: reorganize SMAP handling in user space accesses
	x86: fix SMAP in 32-bit environments
	x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec
	x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end}
	x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec
	x86/bugs, KVM: Support the combination of guest and host IBRS
	x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest
	KVM: SVM: Move spec control call after restore of GS
	x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
	x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
	KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
	bpf: support 8-byte metafield access
	bpf/verifier: Add spi variable to check_stack_write()
	bpf/verifier: Pass instruction index to check_mem_access() and check_xadd()
	bpf: Prevent memory disambiguation attack
	wil6210: missing length check in wmi_set_ie
	posix-timers: Sanitize overrun handling
	mm/hugetlb.c: don't call region_abort if region_chg fails
	hugetlbfs: fix offset overflow in hugetlbfs mmap
	hugetlbfs: check for pgoff value overflow
	hugetlbfs: fix bug in pgoff overflow checking
	swiotlb: clean up reporting
	sr: pass down correctly sized SCSI sense buffer
	mm: remove write/force parameters from __get_user_pages_locked()
	mm: remove write/force parameters from __get_user_pages_unlocked()
	mm/nommu.c: Switch __get_user_pages_unlocked() to use __get_user_pages()
	mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
	mm: replace get_user_pages_locked() write/force parameters with gup_flags
	mm: replace get_vaddr_frames() write/force parameters with gup_flags
	mm: replace get_user_pages() write/force parameters with gup_flags
	mm: replace __access_remote_vm() write parameter with gup_flags
	mm: replace access_remote_vm() write parameter with gup_flags
	proc: don't use FOLL_FORCE for reading cmdline and environment
	proc: do not access cmdline nor environ from file-backed areas
	media: dvb-frontends: fix i2c access helpers for KASAN
	matroxfb: fix size of memcpy
	staging: speakup: Replace strncpy with memcpy
	rocker: fix rocker_tlv_put_* functions for KASAN
	selftests: Move networking/timestamping from Documentation
	Linux 4.4.168

Change-Id: Icd04a723739ae5e38258a2f6b0aee875f306a0bc
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

1 files changed, 77 insertions, 21 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 35dfa9e9d69e..c43ca9857479 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -191,6 +191,7 @@ struct bpf_insn_aux_data {
 		enum bpf_reg_type ptr_type;	/* pointer type for load/store insns */
 		struct bpf_map *map_ptr;	/* pointer for call insn into lookup_elem */
 	};
+	int sanitize_stack_off; /* stack slot to be cleared */
 	bool seen; /* this insn was processed by the verifier */
 };
 
@@ -569,10 +570,11 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
 /* check_stack_read/write functions track spill/fill of registers,
  * stack boundary and alignment are checked in check_mem_access()
  */
-static int check_stack_write(struct verifier_state *state, int off, int size,
-			     int value_regno)
+static int check_stack_write(struct verifier_env *env,
+			     struct verifier_state *state, int off,
+			     int size, int value_regno, int insn_idx)
 {
-	int i;
+	int i, spi = (MAX_BPF_STACK + off) / BPF_REG_SIZE;
 	/* caller checked that off % size == 0 and -MAX_BPF_STACK <= off < 0,
 	 * so it's aligned access and [off, off + size) are within stack limits
 	 */
@@ -587,15 +589,37 @@ static int check_stack_write(struct verifier_state *state, int off, int size,
 		}
 
 		/* save register state */
-		state->spilled_regs[(MAX_BPF_STACK + off) / BPF_REG_SIZE] =
-			state->regs[value_regno];
-
-		for (i = 0; i < BPF_REG_SIZE; i++)
+		state->spilled_regs[spi] = state->regs[value_regno];
+
+		for (i = 0; i < BPF_REG_SIZE; i++) {
+			if (state->stack_slot_type[MAX_BPF_STACK + off + i] == STACK_MISC &&
+			    !env->allow_ptr_leaks) {
+				int *poff = &env->insn_aux_data[insn_idx].sanitize_stack_off;
+				int soff = (-spi - 1) * BPF_REG_SIZE;
+
+				/* detected reuse of integer stack slot with a pointer
+				 * which means either llvm is reusing stack slot or
+				 * an attacker is trying to exploit CVE-2018-3639
+				 * (speculative store bypass)
+				 * Have to sanitize that slot with preemptive
+				 * store of zero.
+				 */
+				if (*poff && *poff != soff) {
+					/* disallow programs where single insn stores
+					 * into two different stack slots, since verifier
+					 * cannot sanitize them
+					 */
+					verbose("insn %d cannot access two stack slots fp%d and fp%d",
+						insn_idx, *poff, soff);
+					return -EINVAL;
+				}
+				*poff = soff;
+			}
 			state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_SPILL;
+		}
 	} else {
 		/* regular write of data into stack */
-		state->spilled_regs[(MAX_BPF_STACK + off) / BPF_REG_SIZE] =
-			(struct reg_state) {};
+		state->spilled_regs[spi] = (struct reg_state) {};
 
 		for (i = 0; i < size; i++)
 			state->stack_slot_type[MAX_BPF_STACK + off + i] = STACK_MISC;
@@ -696,7 +720,7 @@ static bool is_ctx_reg(struct verifier_env *env, int regno)
  * if t==write && value_regno==-1, some unknown value is stored into memory
  * if t==read && value_regno==-1, don't care what we read from memory
  */
-static int check_mem_access(struct verifier_env *env, u32 regno, int off,
+static int check_mem_access(struct verifier_env *env, int insn_idx, u32 regno, int off,
 			    int bpf_size, enum bpf_access_type t,
 			    int value_regno)
 {
@@ -748,7 +772,8 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off,
 				verbose("attempt to corrupt spilled pointer on stack\n");
 				return -EACCES;
 			}
-			err = check_stack_write(state, off, size, value_regno);
+			err = check_stack_write(env, state, off, size,
+						value_regno, insn_idx);
 		} else {
 			err = check_stack_read(state, off, size, value_regno);
 		}
@@ -760,7 +785,7 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off,
 	return err;
 }
 
-static int check_xadd(struct verifier_env *env, struct bpf_insn *insn)
+static int check_xadd(struct verifier_env *env, int insn_idx, struct bpf_insn *insn)
 {
 	struct reg_state *regs = env->cur_state.regs;
 	int err;
@@ -793,13 +818,13 @@ static int check_xadd(struct verifier_env *env, struct bpf_insn *insn)
 	}
 
 	/* check whether atomic_add can read the memory */
-	err = check_mem_access(env, insn->dst_reg, insn->off,
+	err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
 			       BPF_SIZE(insn->code), BPF_READ, -1);
 	if (err)
 		return err;
 
 	/* check whether atomic_add can write into the same memory */
-	return check_mem_access(env, insn->dst_reg, insn->off,
+	return check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
 				BPF_SIZE(insn->code), BPF_WRITE, -1);
 }
 
@@ -1838,13 +1863,14 @@ static int do_check(struct verifier_env *env)
 			/* check that memory (src_reg + off) is readable,
 			 * the state of dst_reg will be updated by this func
 			 */
-			err = check_mem_access(env, insn->src_reg, insn->off,
+			err = check_mem_access(env, insn_idx, insn->src_reg, insn->off,
 					       BPF_SIZE(insn->code), BPF_READ,
 					       insn->dst_reg);
 			if (err)
 				return err;
 
-			if (BPF_SIZE(insn->code) != BPF_W) {
+			if (BPF_SIZE(insn->code) != BPF_W &&
+			    BPF_SIZE(insn->code) != BPF_DW) {
 				insn_idx++;
 				continue;
 			}
@@ -1876,7 +1902,7 @@ static int do_check(struct verifier_env *env)
 			enum bpf_reg_type *prev_dst_type, dst_reg_type;
 
 			if (BPF_MODE(insn->code) == BPF_XADD) {
-				err = check_xadd(env, insn);
+				err = check_xadd(env, insn_idx, insn);
 				if (err)
 					return err;
 				insn_idx++;
@@ -1895,7 +1921,7 @@ static int do_check(struct verifier_env *env)
 			dst_reg_type = regs[insn->dst_reg].type;
 
 			/* check that memory (dst_reg + off) is writeable */
-			err = check_mem_access(env, insn->dst_reg, insn->off,
+			err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
 					       BPF_SIZE(insn->code), BPF_WRITE,
 					       insn->src_reg);
 			if (err)
@@ -1930,7 +1956,7 @@ static int do_check(struct verifier_env *env)
 			}
 
 			/* check that memory (dst_reg + off) is writeable */
-			err = check_mem_access(env, insn->dst_reg, insn->off,
+			err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off,
 					       BPF_SIZE(insn->code), BPF_WRITE,
 					       -1);
 			if (err)
@@ -2220,13 +2246,43 @@ static int convert_ctx_accesses(struct verifier_env *env)
 	for (i = 0; i < insn_cnt; i++, insn++) {
 		u32 cnt;
 
-		if (insn->code == (BPF_LDX | BPF_MEM | BPF_W))
+		if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
+		    insn->code == (BPF_LDX | BPF_MEM | BPF_DW))
 			type = BPF_READ;
-		else if (insn->code == (BPF_STX | BPF_MEM | BPF_W))
+		else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) ||
+			 insn->code == (BPF_STX | BPF_MEM | BPF_DW))
 			type = BPF_WRITE;
 		else
 			continue;
 
+		if (type == BPF_WRITE &&
+		    env->insn_aux_data[i + delta].sanitize_stack_off) {
+			struct bpf_insn patch[] = {
+				/* Sanitize suspicious stack slot with zero.
+				 * There are no memory dependencies for this store,
+				 * since it's only using frame pointer and immediate
+				 * constant of zero
+				 */
+				BPF_ST_MEM(BPF_DW, BPF_REG_FP,
+					   env->insn_aux_data[i + delta].sanitize_stack_off,
+					   0),
+				/* the original STX instruction will immediately
+				 * overwrite the same stack slot with appropriate value
+				 */
+				*insn,
+			};
+
+			cnt = ARRAY_SIZE(patch);
+			new_prog = bpf_patch_insn_data(env, i + delta, patch, cnt);
+			if (!new_prog)
+				return -ENOMEM;
+
+			delta    += cnt - 1;
+			env->prog = new_prog;
+			insn      = new_prog->insnsi + i + delta;
+			continue;
+		}
+
 		if (env->insn_aux_data[i + delta].ptr_type != PTR_TO_CTX)
 			continue;