diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 586 |
1 files changed, 555 insertions, 31 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 51ba84d4d34a..71d86e3024ae 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11,10 +11,12 @@ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. */ +#include <uapi/linux/btf.h> #include <linux/kernel.h> #include <linux/types.h> #include <linux/slab.h> #include <linux/bpf.h> +#include <linux/btf.h> #include <linux/bpf_verifier.h> #include <linux/filter.h> #include <net/netlink.h> @@ -24,6 +26,7 @@ #include <linux/bsearch.h> #include <linux/sort.h> #include <linux/perf_event.h> +#include <linux/ctype.h> #include "disasm.h" @@ -214,6 +217,27 @@ struct bpf_call_arg_meta { static DEFINE_MUTEX(bpf_verifier_lock); +static const struct bpf_line_info * +find_linfo(const struct bpf_verifier_env *env, u32 insn_off) +{ + const struct bpf_line_info *linfo; + const struct bpf_prog *prog; + u32 i, nr_linfo; + + prog = env->prog; + nr_linfo = prog->aux->nr_linfo; + + if (!nr_linfo || insn_off >= prog->len) + return NULL; + + linfo = prog->aux->linfo; + for (i = 1; i < nr_linfo; i++) + if (insn_off < linfo[i].insn_off) + break; + + return &linfo[i - 1]; +} + void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, va_list args) { @@ -264,6 +288,42 @@ __printf(2, 3) static void verbose(void *private_data, const char *fmt, ...) va_end(args); } +static const char *ltrim(const char *s) +{ + while (isspace(*s)) + s++; + + return s; +} + +__printf(3, 4) static void verbose_linfo(struct bpf_verifier_env *env, + u32 insn_off, + const char *prefix_fmt, ...) +{ + const struct bpf_line_info *linfo; + + if (!bpf_verifier_log_needed(&env->log)) + return; + + linfo = find_linfo(env, insn_off); + if (!linfo || linfo == env->prev_linfo) + return; + + if (prefix_fmt) { + va_list args; + + va_start(args, prefix_fmt); + bpf_verifier_vlog(&env->log, prefix_fmt, args); + va_end(args); + } + + verbose(env, "%s\n", + ltrim(btf_name_by_offset(env->prog->aux->btf, + linfo->line_off))); + + env->prev_linfo = linfo; +} + static bool type_is_pkt_pointer(enum bpf_reg_type type) { return type == PTR_TO_PACKET || @@ -337,12 +397,14 @@ static char slot_type_char[] = { static void print_liveness(struct bpf_verifier_env *env, enum bpf_reg_liveness live) { - if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN)) + if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE)) verbose(env, "_"); if (live & REG_LIVE_READ) verbose(env, "r"); if (live & REG_LIVE_WRITTEN) verbose(env, "w"); + if (live & REG_LIVE_DONE) + verbose(env, "D"); } static struct bpf_func_state *func(struct bpf_verifier_env *env, @@ -1072,6 +1134,12 @@ static int mark_reg_read(struct bpf_verifier_env *env, /* if read wasn't screened by an earlier write ... */ if (writes && state->live & REG_LIVE_WRITTEN) break; + if (parent->live & REG_LIVE_DONE) { + verbose(env, "verifier BUG type %s var_off %lld off %d\n", + reg_type_str[parent->type], + parent->var_off.value, parent->off); + return -EFAULT; + } /* ... then we depend on parent's value */ parent->live |= REG_LIVE_READ; state = parent; @@ -1218,6 +1286,10 @@ static int check_stack_write(struct bpf_verifier_env *env, /* regular write of data into stack destroys any spilled ptr */ state->stack[spi].spilled_ptr.type = NOT_INIT; + /* Mark slots as STACK_MISC if they belonged to spilled ptr. */ + if (state->stack[spi].slot_type[0] == STACK_SPILL) + for (i = 0; i < BPF_REG_SIZE; i++) + state->stack[spi].slot_type[i] = STACK_MISC; /* only mark the slot as written if all 8 bytes were written * otherwise read propagation may incorrectly stop too soon @@ -1235,6 +1307,7 @@ static int check_stack_write(struct bpf_verifier_env *env, register_is_null(&cur->regs[value_regno])) type = STACK_ZERO; + /* Mark slots affected by this stack write. */ for (i = 0; i < size; i++) state->stack[spi].slot_type[(slot - i) % BPF_REG_SIZE] = type; @@ -1456,6 +1529,17 @@ static int check_packet_access(struct bpf_verifier_env *env, u32 regno, int off, verbose(env, "R%d offset is outside of the packet\n", regno); return err; } + + /* __check_packet_access has made sure "off + size - 1" is within u16. + * reg->umax_value can't be bigger than MAX_PACKET_OFF which is 0xffff, + * otherwise find_good_pkt_pointers would have refused to set range info + * that __check_packet_access would have rejected this pkt access. + * Therefore, "off + reg->umax_value + size - 1" won't overflow u32. + */ + env->prog->aux->max_pkt_offset = + max_t(u32, env->prog->aux->max_pkt_offset, + off + reg->umax_value + size - 1); + return err; } @@ -3571,12 +3655,15 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return err; if (BPF_SRC(insn->code) == BPF_X) { + struct bpf_reg_state *src_reg = regs + insn->src_reg; + struct bpf_reg_state *dst_reg = regs + insn->dst_reg; + if (BPF_CLASS(insn->code) == BPF_ALU64) { /* case: R1 = R2 * copy register state to dest reg */ - regs[insn->dst_reg] = regs[insn->src_reg]; - regs[insn->dst_reg].live |= REG_LIVE_WRITTEN; + *dst_reg = *src_reg; + dst_reg->live |= REG_LIVE_WRITTEN; } else { /* R1 = (u32) R2 */ if (is_pointer_value(env, insn->src_reg)) { @@ -3584,9 +3671,14 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) "R%d partial copy of pointer\n", insn->src_reg); return -EACCES; + } else if (src_reg->type == SCALAR_VALUE) { + *dst_reg = *src_reg; + dst_reg->live |= REG_LIVE_WRITTEN; + } else { + mark_reg_unknown(env, regs, + insn->dst_reg); } - mark_reg_unknown(env, regs, insn->dst_reg); - coerce_reg_to_size(®s[insn->dst_reg], 4); + coerce_reg_to_size(dst_reg, 4); } } else { /* case: R = imm @@ -3637,11 +3729,6 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return -EINVAL; } - if (opcode == BPF_ARSH && BPF_CLASS(insn->code) != BPF_ALU64) { - verbose(env, "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; @@ -3772,6 +3859,12 @@ static int is_branch_taken(struct bpf_reg_state *reg, u64 val, u8 opcode) if (tnum_is_const(reg->var_off)) return !tnum_equals_const(reg->var_off, val); break; + case BPF_JSET: + if ((~reg->var_off.mask & reg->var_off.value) & val) + return 1; + if (!((reg->var_off.mask | reg->var_off.value) & val)) + return 0; + break; case BPF_JGT: if (reg->umin_value > val) return 1; @@ -3856,6 +3949,13 @@ static void reg_set_min_max(struct bpf_reg_state *true_reg, */ __mark_reg_known(false_reg, val); break; + case BPF_JSET: + false_reg->var_off = tnum_and(false_reg->var_off, + tnum_const(~val)); + if (is_power_of_2(val)) + true_reg->var_off = tnum_or(true_reg->var_off, + tnum_const(val)); + break; case BPF_JGT: false_reg->umax_value = min(false_reg->umax_value, val); true_reg->umin_value = max(true_reg->umin_value, val + 1); @@ -3928,6 +4028,13 @@ static void reg_set_min_max_inv(struct bpf_reg_state *true_reg, */ __mark_reg_known(false_reg, val); break; + case BPF_JSET: + false_reg->var_off = tnum_and(false_reg->var_off, + tnum_const(~val)); + if (is_power_of_2(val)) + true_reg->var_off = tnum_or(true_reg->var_off, + tnum_const(val)); + break; case BPF_JGT: true_reg->umax_value = min(true_reg->umax_value, val - 1); false_reg->umin_value = max(false_reg->umin_value, val); @@ -4545,6 +4652,7 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env) return 0; if (w < 0 || w >= env->prog->len) { + verbose_linfo(env, t, "%d: ", t); verbose(env, "jump out of range from insn %d to %d\n", t, w); return -EINVAL; } @@ -4562,6 +4670,8 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env) insn_stack[cur_stack++] = w; return 1; } else if ((insn_state[w] & 0xF0) == DISCOVERED) { + verbose_linfo(env, t, "%d: ", t); + verbose_linfo(env, w, "%d: ", w); verbose(env, "back-edge from insn %d to %d\n", t, w); return -EINVAL; } else if (insn_state[w] == EXPLORED) { @@ -4584,10 +4694,6 @@ static int check_cfg(struct bpf_verifier_env *env) int ret = 0; int i, t; - ret = check_subprogs(env); - if (ret < 0) - return ret; - insn_state = kcalloc(insn_cnt, sizeof(int), GFP_KERNEL); if (!insn_state) return -ENOMEM; @@ -4696,6 +4802,277 @@ err_free: return ret; } +/* The minimum supported BTF func info size */ +#define MIN_BPF_FUNCINFO_SIZE 8 +#define MAX_FUNCINFO_REC_SIZE 252 + +static int check_btf_func(struct bpf_verifier_env *env, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + u32 i, nfuncs, urec_size, min_size, prev_offset; + u32 krec_size = sizeof(struct bpf_func_info); + struct bpf_func_info *krecord; + const struct btf_type *type; + struct bpf_prog *prog; + const struct btf *btf; + void __user *urecord; + int ret = 0; + + nfuncs = attr->func_info_cnt; + if (!nfuncs) + return 0; + + if (nfuncs != env->subprog_cnt) { + verbose(env, "number of funcs in func_info doesn't match number of subprogs\n"); + return -EINVAL; + } + + urec_size = attr->func_info_rec_size; + if (urec_size < MIN_BPF_FUNCINFO_SIZE || + urec_size > MAX_FUNCINFO_REC_SIZE || + urec_size % sizeof(u32)) { + verbose(env, "invalid func info rec size %u\n", urec_size); + return -EINVAL; + } + + prog = env->prog; + btf = prog->aux->btf; + + urecord = u64_to_user_ptr(attr->func_info); + min_size = min_t(u32, krec_size, urec_size); + + krecord = kvcalloc(nfuncs, krec_size, GFP_KERNEL | __GFP_NOWARN); + if (!krecord) + return -ENOMEM; + + for (i = 0; i < nfuncs; i++) { + ret = bpf_check_uarg_tail_zero(urecord, krec_size, urec_size); + if (ret) { + if (ret == -E2BIG) { + verbose(env, "nonzero tailing record in func info"); + /* set the size kernel expects so loader can zero + * out the rest of the record. + */ + if (put_user(min_size, &uattr->func_info_rec_size)) + ret = -EFAULT; + } + goto err_free; + } + + if (copy_from_user(&krecord[i], urecord, min_size)) { + ret = -EFAULT; + goto err_free; + } + + /* check insn_off */ + if (i == 0) { + if (krecord[i].insn_off) { + verbose(env, + "nonzero insn_off %u for the first func info record", + krecord[i].insn_off); + ret = -EINVAL; + goto err_free; + } + } else if (krecord[i].insn_off <= prev_offset) { + verbose(env, + "same or smaller insn offset (%u) than previous func info record (%u)", + krecord[i].insn_off, prev_offset); + ret = -EINVAL; + goto err_free; + } + + if (env->subprog_info[i].start != krecord[i].insn_off) { + verbose(env, "func_info BTF section doesn't match subprog layout in BPF program\n"); + ret = -EINVAL; + goto err_free; + } + + /* check type_id */ + type = btf_type_by_id(btf, krecord[i].type_id); + if (!type || BTF_INFO_KIND(type->info) != BTF_KIND_FUNC) { + verbose(env, "invalid type id %d in func info", + krecord[i].type_id); + ret = -EINVAL; + goto err_free; + } + + prev_offset = krecord[i].insn_off; + urecord += urec_size; + } + + prog->aux->func_info = krecord; + prog->aux->func_info_cnt = nfuncs; + return 0; + +err_free: + kvfree(krecord); + return ret; +} + +static void adjust_btf_func(struct bpf_verifier_env *env) +{ + int i; + + if (!env->prog->aux->func_info) + return; + + for (i = 0; i < env->subprog_cnt; i++) + env->prog->aux->func_info[i].insn_off = env->subprog_info[i].start; +} + +#define MIN_BPF_LINEINFO_SIZE (offsetof(struct bpf_line_info, line_col) + \ + sizeof(((struct bpf_line_info *)(0))->line_col)) +#define MAX_LINEINFO_REC_SIZE MAX_FUNCINFO_REC_SIZE + +static int check_btf_line(struct bpf_verifier_env *env, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + u32 i, s, nr_linfo, ncopy, expected_size, rec_size, prev_offset = 0; + struct bpf_subprog_info *sub; + struct bpf_line_info *linfo; + struct bpf_prog *prog; + const struct btf *btf; + void __user *ulinfo; + int err; + + nr_linfo = attr->line_info_cnt; + if (!nr_linfo) + return 0; + + rec_size = attr->line_info_rec_size; + if (rec_size < MIN_BPF_LINEINFO_SIZE || + rec_size > MAX_LINEINFO_REC_SIZE || + rec_size & (sizeof(u32) - 1)) + return -EINVAL; + + /* Need to zero it in case the userspace may + * pass in a smaller bpf_line_info object. + */ + linfo = kvcalloc(nr_linfo, sizeof(struct bpf_line_info), + GFP_KERNEL | __GFP_NOWARN); + if (!linfo) + return -ENOMEM; + + prog = env->prog; + btf = prog->aux->btf; + + s = 0; + sub = env->subprog_info; + ulinfo = u64_to_user_ptr(attr->line_info); + expected_size = sizeof(struct bpf_line_info); + ncopy = min_t(u32, expected_size, rec_size); + for (i = 0; i < nr_linfo; i++) { + err = bpf_check_uarg_tail_zero(ulinfo, expected_size, rec_size); + if (err) { + if (err == -E2BIG) { + verbose(env, "nonzero tailing record in line_info"); + if (put_user(expected_size, + &uattr->line_info_rec_size)) + err = -EFAULT; + } + goto err_free; + } + + if (copy_from_user(&linfo[i], ulinfo, ncopy)) { + err = -EFAULT; + goto err_free; + } + + /* + * Check insn_off to ensure + * 1) strictly increasing AND + * 2) bounded by prog->len + * + * The linfo[0].insn_off == 0 check logically falls into + * the later "missing bpf_line_info for func..." case + * because the first linfo[0].insn_off must be the + * first sub also and the first sub must have + * subprog_info[0].start == 0. + */ + if ((i && linfo[i].insn_off <= prev_offset) || + linfo[i].insn_off >= prog->len) { + verbose(env, "Invalid line_info[%u].insn_off:%u (prev_offset:%u prog->len:%u)\n", + i, linfo[i].insn_off, prev_offset, + prog->len); + err = -EINVAL; + goto err_free; + } + + if (!prog->insnsi[linfo[i].insn_off].code) { + verbose(env, + "Invalid insn code at line_info[%u].insn_off\n", + i); + err = -EINVAL; + goto err_free; + } + + if (!btf_name_by_offset(btf, linfo[i].line_off) || + !btf_name_by_offset(btf, linfo[i].file_name_off)) { + verbose(env, "Invalid line_info[%u].line_off or .file_name_off\n", i); + err = -EINVAL; + goto err_free; + } + + if (s != env->subprog_cnt) { + if (linfo[i].insn_off == sub[s].start) { + sub[s].linfo_idx = i; + s++; + } else if (sub[s].start < linfo[i].insn_off) { + verbose(env, "missing bpf_line_info for func#%u\n", s); + err = -EINVAL; + goto err_free; + } + } + + prev_offset = linfo[i].insn_off; + ulinfo += rec_size; + } + + if (s != env->subprog_cnt) { + verbose(env, "missing bpf_line_info for %u funcs starting from func#%u\n", + env->subprog_cnt - s, s); + err = -EINVAL; + goto err_free; + } + + prog->aux->linfo = linfo; + prog->aux->nr_linfo = nr_linfo; + + return 0; + +err_free: + kvfree(linfo); + return err; +} + +static int check_btf_info(struct bpf_verifier_env *env, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + struct btf *btf; + int err; + + if (!attr->func_info_cnt && !attr->line_info_cnt) + return 0; + + btf = btf_get_by_fd(attr->prog_btf_fd); + if (IS_ERR(btf)) + return PTR_ERR(btf); + env->prog->aux->btf = btf; + + err = check_btf_func(env, attr, uattr); + if (err) + return err; + + err = check_btf_line(env, attr, uattr); + if (err) + return err; + + return 0; +} + /* check %cur's range satisfies %old's */ static bool range_within(struct bpf_reg_state *old, struct bpf_reg_state *cur) @@ -4742,6 +5119,102 @@ static bool check_ids(u32 old_id, u32 cur_id, struct idpair *idmap) return false; } +static void clean_func_state(struct bpf_verifier_env *env, + struct bpf_func_state *st) +{ + enum bpf_reg_liveness live; + int i, j; + + for (i = 0; i < BPF_REG_FP; i++) { + live = st->regs[i].live; + /* liveness must not touch this register anymore */ + st->regs[i].live |= REG_LIVE_DONE; + if (!(live & REG_LIVE_READ)) + /* since the register is unused, clear its state + * to make further comparison simpler + */ + __mark_reg_not_init(&st->regs[i]); + } + + for (i = 0; i < st->allocated_stack / BPF_REG_SIZE; i++) { + live = st->stack[i].spilled_ptr.live; + /* liveness must not touch this stack slot anymore */ + st->stack[i].spilled_ptr.live |= REG_LIVE_DONE; + if (!(live & REG_LIVE_READ)) { + __mark_reg_not_init(&st->stack[i].spilled_ptr); + for (j = 0; j < BPF_REG_SIZE; j++) + st->stack[i].slot_type[j] = STACK_INVALID; + } + } +} + +static void clean_verifier_state(struct bpf_verifier_env *env, + struct bpf_verifier_state *st) +{ + int i; + + if (st->frame[0]->regs[0].live & REG_LIVE_DONE) + /* all regs in this state in all frames were already marked */ + return; + + for (i = 0; i <= st->curframe; i++) + clean_func_state(env, st->frame[i]); +} + +/* the parentage chains form a tree. + * the verifier states are added to state lists at given insn and + * pushed into state stack for future exploration. + * when the verifier reaches bpf_exit insn some of the verifer states + * stored in the state lists have their final liveness state already, + * but a lot of states will get revised from liveness point of view when + * the verifier explores other branches. + * Example: + * 1: r0 = 1 + * 2: if r1 == 100 goto pc+1 + * 3: r0 = 2 + * 4: exit + * when the verifier reaches exit insn the register r0 in the state list of + * insn 2 will be seen as !REG_LIVE_READ. Then the verifier pops the other_branch + * of insn 2 and goes exploring further. At the insn 4 it will walk the + * parentage chain from insn 4 into insn 2 and will mark r0 as REG_LIVE_READ. + * + * Since the verifier pushes the branch states as it sees them while exploring + * the program the condition of walking the branch instruction for the second + * time means that all states below this branch were already explored and + * their final liveness markes are already propagated. + * Hence when the verifier completes the search of state list in is_state_visited() + * we can call this clean_live_states() function to mark all liveness states + * as REG_LIVE_DONE to indicate that 'parent' pointers of 'struct bpf_reg_state' + * will not be used. + * This function also clears the registers and stack for states that !READ + * to simplify state merging. + * + * Important note here that walking the same branch instruction in the callee + * doesn't meant that the states are DONE. The verifier has to compare + * the callsites + */ +static void clean_live_states(struct bpf_verifier_env *env, int insn, + struct bpf_verifier_state *cur) +{ + struct bpf_verifier_state_list *sl; + int i; + + sl = env->explored_states[insn]; + if (!sl) + return; + + while (sl != STATE_LIST_MARK) { + if (sl->state.curframe != cur->curframe) + goto next; + for (i = 0; i <= cur->curframe; i++) + if (sl->state.frame[i]->callsite != cur->frame[i]->callsite) + goto next; + clean_verifier_state(env, &sl->state); +next: + sl = sl->next; + } +} + /* Returns true if (rold safe implies rcur safe) */ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur, struct idpair *idmap) @@ -4855,12 +5328,6 @@ static bool stacksafe(struct bpf_func_state *old, { int i, spi; - /* if explored stack has more populated slots than current stack - * such stacks are not equivalent - */ - if (old->allocated_stack > cur->allocated_stack) - return false; - /* walk slots of the explored stack and ignore any additional * slots in the current stack, since explored(safe) state * didn't use them @@ -4868,12 +5335,21 @@ static bool stacksafe(struct bpf_func_state *old, for (i = 0; i < old->allocated_stack; i++) { spi = i / BPF_REG_SIZE; - if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)) + if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)) { + i += BPF_REG_SIZE - 1; /* explored state didn't use this */ continue; + } if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID) continue; + + /* explored stack has more populated slots than current stack + * and these slots were used + */ + if (i >= cur->allocated_stack) + return false; + /* if old state was safe with misc data in the stack * it will be safe with zero-initialized stack. * The opposite is not true @@ -5057,6 +5533,8 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx) */ return 0; + clean_live_states(env, insn_idx, cur); + while (sl != STATE_LIST_MARK) { if (states_equal(env, &sl->state, cur)) { /* reached equivalent register/stack state, @@ -5176,6 +5654,8 @@ static int do_check(struct bpf_verifier_env *env) int insn_processed = 0; bool do_print_state = false; + env->prev_linfo = NULL; + state = kzalloc(sizeof(struct bpf_verifier_state), GFP_KERNEL); if (!state) return -ENOMEM; @@ -5249,6 +5729,7 @@ static int do_check(struct bpf_verifier_env *env) .private_data = env, }; + verbose_linfo(env, insn_idx, "; "); verbose(env, "%d: ", insn_idx); print_bpf_insn(&cbs, insn, env->allow_ptr_leaks); } @@ -5789,10 +6270,10 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) int i, cnt, size, ctx_field_size, delta = 0; const int insn_cnt = env->prog->len; struct bpf_insn insn_buf[16], *insn; + u32 target_size, size_default, off; struct bpf_prog *new_prog; enum bpf_access_type type; bool is_narrower_load; - u32 target_size; if (ops->gen_prologue || env->seen_direct_write) { if (!ops->gen_prologue) { @@ -5885,9 +6366,9 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) * we will apply proper mask to the result. */ is_narrower_load = size < ctx_field_size; + size_default = bpf_ctx_off_adjust_machine(ctx_field_size); + off = insn->off; if (is_narrower_load) { - u32 size_default = bpf_ctx_off_adjust_machine(ctx_field_size); - u32 off = insn->off; u8 size_code; if (type == BPF_WRITE) { @@ -5915,12 +6396,23 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) } if (is_narrower_load && size < target_size) { - if (ctx_field_size <= 4) + u8 shift = (off & (size_default - 1)) * 8; + + if (ctx_field_size <= 4) { + if (shift) + insn_buf[cnt++] = BPF_ALU32_IMM(BPF_RSH, + insn->dst_reg, + shift); insn_buf[cnt++] = BPF_ALU32_IMM(BPF_AND, insn->dst_reg, (1 << size * 8) - 1); - else + } else { + if (shift) + insn_buf[cnt++] = BPF_ALU64_IMM(BPF_RSH, + insn->dst_reg, + shift); insn_buf[cnt++] = BPF_ALU64_IMM(BPF_AND, insn->dst_reg, (1 << size * 8) - 1); + } } new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); @@ -5943,7 +6435,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) int i, j, subprog_start, subprog_end = 0, len, subprog; struct bpf_insn *insn; void *old_bpf_func; - int err = -ENOMEM; + int err; if (env->subprog_cnt <= 1) return 0; @@ -5974,6 +6466,11 @@ static int jit_subprogs(struct bpf_verifier_env *env) insn->imm = 1; } + err = bpf_prog_alloc_jited_linfo(prog); + if (err) + goto out_undo_insn; + + err = -ENOMEM; func = kcalloc(env->subprog_cnt, sizeof(prog), GFP_KERNEL); if (!func) goto out_undo_insn; @@ -5993,12 +6490,21 @@ static int jit_subprogs(struct bpf_verifier_env *env) if (bpf_prog_calc_tag(func[i])) goto out_free; func[i]->is_func = 1; + func[i]->aux->func_idx = i; + /* the btf and func_info will be freed only at prog->aux */ + func[i]->aux->btf = prog->aux->btf; + func[i]->aux->func_info = prog->aux->func_info; + /* Use bpf_prog_F_tag to indicate functions in stack traces. * Long term would need debug info to populate names */ func[i]->aux->name[0] = 'F'; func[i]->aux->stack_depth = env->subprog_info[i].stack_depth; func[i]->jit_requested = 1; + func[i]->aux->linfo = prog->aux->linfo; + func[i]->aux->nr_linfo = prog->aux->nr_linfo; + func[i]->aux->jited_linfo = prog->aux->jited_linfo; + func[i]->aux->linfo_idx = env->subprog_info[i].linfo_idx; func[i] = bpf_int_jit_compile(func[i]); if (!func[i]->jited) { err = -ENOTSUPP; @@ -6072,6 +6578,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) prog->bpf_func = func[0]->bpf_func; prog->aux->func = func; prog->aux->func_cnt = env->subprog_cnt; + bpf_prog_free_unused_jited_linfo(prog); return 0; out_free: for (i = 0; i < env->subprog_cnt; i++) @@ -6088,6 +6595,7 @@ out_undo_insn: insn->off = 0; insn->imm = env->insn_aux_data[i].call_imm; } + bpf_prog_free_jited_linfo(prog); return err; } @@ -6220,6 +6728,7 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) */ prog->cb_access = 1; env->prog->aux->stack_depth = MAX_BPF_STACK; + env->prog->aux->max_pkt_offset = MAX_PACKET_OFF; /* mark bpf_tail_call as different opcode to avoid * conditional branch in the interpeter for every normal @@ -6384,7 +6893,8 @@ static void free_states(struct bpf_verifier_env *env) kfree(env->explored_states); } -int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) +int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, + union bpf_attr __user *uattr) { struct bpf_verifier_env *env; struct bpf_verifier_log *log; @@ -6432,13 +6942,15 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) env->strict_alignment = !!(attr->prog_flags & BPF_F_STRICT_ALIGNMENT); if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) env->strict_alignment = true; + if (attr->prog_flags & BPF_F_ANY_ALIGNMENT) + env->strict_alignment = false; ret = replace_map_fd_with_map_ptr(env); if (ret < 0) goto skip_full_check; if (bpf_prog_is_dev_bound(env->prog->aux)) { - ret = bpf_prog_offload_verifier_prep(env); + ret = bpf_prog_offload_verifier_prep(env->prog); if (ret) goto skip_full_check; } @@ -6452,6 +6964,14 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) env->allow_ptr_leaks = capable(CAP_SYS_ADMIN); + ret = check_subprogs(env); + if (ret < 0) + goto skip_full_check; + + ret = check_btf_info(env, attr, uattr); + if (ret < 0) + goto skip_full_check; + ret = check_cfg(env); if (ret < 0) goto skip_full_check; @@ -6470,10 +6990,11 @@ skip_full_check: free_states(env); if (ret == 0) - sanitize_dead_code(env); + ret = check_max_stack_depth(env); + /* instruction rewrites happen after this point */ if (ret == 0) - ret = check_max_stack_depth(env); + sanitize_dead_code(env); if (ret == 0) /* program is valid, convert *(u32*)(ctx + off) accesses */ @@ -6513,6 +7034,9 @@ skip_full_check: convert_pseudo_ld_imm64(env); } + if (ret == 0) + adjust_btf_func(env); + err_release_maps: if (!env->prog->aux->used_maps) /* if we didn't copy map pointers into bpf_prog_info, release |