diff options
| author | Srinivasarao P <spathi@codeaurora.org> | 2018-02-05 11:56:41 +0530 |
|---|---|---|
| committer | Srinivasarao P <spathi@codeaurora.org> | 2018-02-05 11:59:38 +0530 |
| commit | 2fd547e8d1f09628007fc2bca04ccff416bb9d76 (patch) | |
| tree | 5c38fac921c4ed2778f6c9c4d5b732614528bd87 /kernel/bpf/verifier.c | |
| parent | 38cacfd106259c2f10d8ee33047b7212d7844732 (diff) | |
| parent | aa856bd83c43969dc3e8f8c0e97e6105e91aef76 (diff) | |
Merge android-4.4.115 (aa856bd) into msm-4.4
* refs/heads/tmp-aa856bd
Linux 4.4.115
spi: imx: do not access registers while clocks disabled
serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS
selinux: general protection fault in sock_has_perm
usb: uas: unconditionally bring back host after reset
usb: f_fs: Prevent gadget unbind if it is already unbound
USB: serial: simple: add Motorola Tetra driver
usbip: list: don't list devices attached to vhci_hcd
usbip: prevent bind loops on devices attached to vhci_hcd
USB: serial: io_edgeport: fix possible sleep-in-atomic
CDC-ACM: apply quirk for card reader
USB: cdc-acm: Do not log urb submission errors on disconnect
USB: serial: pl2303: new device id for Chilitag
usb: option: Add support for FS040U modem
staging: rtl8188eu: Fix incorrect response to SIOCGIWESSID
usb: gadget: don't dereference g until after it has been null checked
media: usbtv: add a new usbid
scsi: ufs: ufshcd: fix potential NULL pointer dereference in ufshcd_config_vreg
scsi: aacraid: Prevent crash in case of free interrupt during scsi EH path
xfs: ubsan fixes
drm/omap: Fix error handling path in 'omap_dmm_probe()'
kmemleak: add scheduling point to kmemleak_scan()
SUNRPC: Allow connect to return EHOSTUNREACH
quota: Check for register_shrinker() failure.
net: ethernet: xilinx: Mark XILINX_LL_TEMAC broken on 64-bit
hwmon: (pmbus) Use 64bit math for DIRECT format values
lockd: fix "list_add double add" caused by legacy signal interface
nfsd: check for use of the closed special stateid
grace: replace BUG_ON by WARN_ONCE in exit_net hook
nfsd: Ensure we check stateid validity in the seqid operation checks
nfsd: CLOSE SHOULD return the invalid special stateid for NFSv4.x (x>0)
xen-netfront: remove warning when unloading module
KVM: VMX: Fix rflags cache during vCPU reset
btrfs: fix deadlock when writing out space cache
mac80211: fix the update of path metric for RANN frame
openvswitch: fix the incorrect flow action alloc size
drm/amdkfd: Fix SDMA oversubsription handling
drm/amdkfd: Fix SDMA ring buffer size calculation
drm/amdgpu: Fix SDMA load/unload sequence on HWS disabled mode
bcache: check return value of register_shrinker
cpufreq: Add Loongson machine dependencies
ACPI / bus: Leave modalias empty for devices which are not present
KVM: x86: ioapic: Preserve read-only values in the redirection table
KVM: x86: ioapic: Clear Remote IRR when entry is switched to edge-triggered
KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race
KVM: X86: Fix operand/address-size during instruction decoding
KVM: x86: Don't re-execute instruction when not passing CR2 value
KVM: x86: emulator: Return to user-mode on L1 CPL=0 emulation failure
igb: Free IRQs when device is hotplugged
mtd: nand: denali_pci: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
gpio: ath79: add missing MODULE_DESCRIPTION/LICENSE
gpio: iop: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
power: reset: zx-reboot: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
crypto: af_alg - whitelist mask and type
crypto: aesni - handle zero length dst buffer
ALSA: seq: Make ioctls race-free
kaiser: fix intel_bts perf crashes
x86/pti: Make unpoison of pgd for trusted boot work for real
bpf: reject stores into ctx via st and xadd
bpf: fix 32-bit divide by zero
bpf: fix divides by zero
bpf: avoid false sharing of map refcount with max_entries
bpf: arsh is not supported in 32 bit alu thus reject it
bpf: introduce BPF_JIT_ALWAYS_ON config
bpf: fix bpf_tail_call() x64 JIT
x86: bpf_jit: small optimization in emit_bpf_tail_call()
bpf: fix branch pruning logic
loop: fix concurrent lo_open/lo_release
ANDROID: sdcardfs: Protect set_top
ANDROID: fsnotify: Notify lower fs of open
Revert "ANDROID: sdcardfs: notify lower file of opens"
ANDROID: sdcardfs: Use lower getattr times/size
ANDROID: sched/rt: schedtune: Add boost retention to RT
Conflicts:
arch/x86/Kconfig
kernel/sched/rt.c
Change-Id: I91b08e1b8e0a1c6ca9c245597acad0bf197f9527
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 014c2d759916..c14003840bc5 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 */ }; + bool seen; /* this insn was processed by the verifier */ }; #define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ @@ -682,6 +683,13 @@ static bool is_pointer_value(struct verifier_env *env, int regno) } } +static bool is_ctx_reg(struct verifier_env *env, int regno) +{ + const struct reg_state *reg = &env->cur_state.regs[regno]; + + return reg->type == PTR_TO_CTX; +} + /* check whether memory at (regno + off) is accessible for t = (read | write) * if t==write, value_regno is a register which value is stored into memory * if t==read, value_regno is a register which will receive the value from memory @@ -778,6 +786,12 @@ static int check_xadd(struct verifier_env *env, struct bpf_insn *insn) return -EACCES; } + if (is_ctx_reg(env, insn->dst_reg)) { + verbose("BPF_XADD stores into R%d context is not allowed\n", + insn->dst_reg); + return -EACCES; + } + /* check whether atomic_add can read the memory */ err = check_mem_access(env, insn->dst_reg, insn->off, BPF_SIZE(insn->code), BPF_READ, -1); @@ -1164,6 +1178,11 @@ static int check_alu_op(struct verifier_env *env, struct bpf_insn *insn) return -EINVAL; } + if (opcode == BPF_ARSH && BPF_CLASS(insn->code) != BPF_ALU64) { + verbose("BPF_ARSH not supported for 32 bit ALU\n"); + return -EINVAL; + } + if ((opcode == BPF_LSH || opcode == BPF_RSH || opcode == BPF_ARSH) && BPF_SRC(insn->code) == BPF_K) { int size = BPF_CLASS(insn->code) == BPF_ALU64 ? 64 : 32; @@ -1793,6 +1812,7 @@ static int do_check(struct verifier_env *env) print_bpf_insn(env, insn); } + env->insn_aux_data[insn_idx].seen = true; if (class == BPF_ALU || class == BPF_ALU64) { err = check_alu_op(env, insn); if (err) @@ -1902,6 +1922,12 @@ static int do_check(struct verifier_env *env) if (err) return err; + if (is_ctx_reg(env, insn->dst_reg)) { + verbose("BPF_ST stores into R%d context is not allowed\n", + insn->dst_reg); + return -EACCES; + } + /* check that memory (dst_reg + off) is writeable */ err = check_mem_access(env, insn->dst_reg, insn->off, BPF_SIZE(insn->code), BPF_WRITE, @@ -1988,6 +2014,7 @@ process_bpf_exit: return err; insn_idx++; + env->insn_aux_data[insn_idx].seen = true; } else { verbose("invalid BPF_LD mode\n"); return -EINVAL; @@ -2125,6 +2152,7 @@ static int adjust_insn_aux_data(struct verifier_env *env, u32 prog_len, u32 off, u32 cnt) { struct bpf_insn_aux_data *new_data, *old_data = env->insn_aux_data; + int i; if (cnt == 1) return 0; @@ -2134,6 +2162,8 @@ static int adjust_insn_aux_data(struct verifier_env *env, u32 prog_len, memcpy(new_data, old_data, sizeof(struct bpf_insn_aux_data) * off); memcpy(new_data + off + cnt - 1, old_data + off, sizeof(struct bpf_insn_aux_data) * (prog_len - off - cnt + 1)); + for (i = off; i < off + cnt - 1; i++) + new_data[i].seen = true; env->insn_aux_data = new_data; vfree(old_data); return 0; @@ -2152,6 +2182,25 @@ static struct bpf_prog *bpf_patch_insn_data(struct verifier_env *env, u32 off, return new_prog; } +/* The verifier does more data flow analysis than llvm and will not explore + * branches that are dead at run time. Malicious programs can have dead code + * too. Therefore replace all dead at-run-time code with nops. + */ +static void sanitize_dead_code(struct verifier_env *env) +{ + struct bpf_insn_aux_data *aux_data = env->insn_aux_data; + struct bpf_insn nop = BPF_MOV64_REG(BPF_REG_0, BPF_REG_0); + struct bpf_insn *insn = env->prog->insnsi; + const int insn_cnt = env->prog->len; + int i; + + for (i = 0; i < insn_cnt; i++) { + if (aux_data[i].seen) + continue; + memcpy(insn + i, &nop, sizeof(nop)); + } +} + /* convert load instructions that access fields of 'struct __sk_buff' * into sequence of instructions that access fields of 'struct sk_buff' */ @@ -2218,6 +2267,24 @@ static int fixup_bpf_calls(struct verifier_env *env) int i, cnt, delta = 0; for (i = 0; i < insn_cnt; i++, insn++) { + if (insn->code == (BPF_ALU | BPF_MOD | BPF_X) || + insn->code == (BPF_ALU | BPF_DIV | BPF_X)) { + /* due to JIT bugs clear upper 32-bits of src register + * before div/mod operation + */ + insn_buf[0] = BPF_MOV32_REG(insn->src_reg, insn->src_reg); + insn_buf[1] = *insn; + cnt = 2; + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } + if (insn->code != (BPF_JMP | BPF_CALL)) continue; @@ -2371,6 +2438,9 @@ skip_full_check: free_states(env); if (ret == 0) + sanitize_dead_code(env); + + if (ret == 0) /* program is valid, convert *(u32*)(ctx + off) accesses */ ret = convert_ctx_accesses(env); |
