diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 396490cf7316..acaa935ed977 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -897,6 +897,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) image_ptr = jit_data->image; header = jit_data->header; extra_pass = true; + image_size = sizeof(u32) * ctx.idx; goto skip_init_ctx; } memset(&ctx, 0, sizeof(ctx)); diff --git a/arch/sparc/net/bpf_jit_comp_64.c b/arch/sparc/net/bpf_jit_comp_64.c index 22aff21fa44d..635fdefd4ae2 100644 --- a/arch/sparc/net/bpf_jit_comp_64.c +++ b/arch/sparc/net/bpf_jit_comp_64.c @@ -1509,11 +1509,19 @@ static void jit_fill_hole(void *area, unsigned int size) *ptr++ = 0x91d02005; /* ta 5 */ } +struct sparc64_jit_data { + struct bpf_binary_header *header; + u8 *image; + struct jit_ctx ctx; +}; + struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) { struct bpf_prog *tmp, *orig_prog = prog; + struct sparc64_jit_data *jit_data; struct bpf_binary_header *header; bool tmp_blinded = false; + bool extra_pass = false; struct jit_ctx ctx; u32 image_size; u8 *image_ptr; @@ -1533,13 +1541,31 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) prog = tmp; } + jit_data = prog->aux->jit_data; + if (!jit_data) { + jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL); + if (!jit_data) { + prog = orig_prog; + goto out; + } + prog->aux->jit_data = jit_data; + } + if (jit_data->ctx.offset) { + ctx = jit_data->ctx; + image_ptr = jit_data->image; + header = jit_data->header; + extra_pass = true; + image_size = sizeof(u32) * ctx.idx; + goto skip_init_ctx; + } + memset(&ctx, 0, sizeof(ctx)); ctx.prog = prog; ctx.offset = kcalloc(prog->len, sizeof(unsigned int), GFP_KERNEL); if (ctx.offset == NULL) { prog = orig_prog; - goto out; + goto out_off; } /* Fake pass to detect features used, and get an accurate assessment @@ -1562,7 +1588,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) } ctx.image = (u32 *)image_ptr; - +skip_init_ctx: for (pass = 1; pass < 3; pass++) { ctx.idx = 0; @@ -1593,14 +1619,24 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) bpf_flush_icache(header, (u8 *)header + (header->pages * PAGE_SIZE)); - bpf_jit_binary_lock_ro(header); + if (!prog->is_func || extra_pass) { + bpf_jit_binary_lock_ro(header); + } else { + jit_data->ctx = ctx; + jit_data->image = image_ptr; + jit_data->header = header; + } prog->bpf_func = (void *)ctx.image; prog->jited = 1; prog->jited_len = image_size; + if (!prog->is_func || extra_pass) { out_off: - kfree(ctx.offset); + kfree(ctx.offset); + kfree(jit_data); + prog->aux->jit_data = NULL; + } out: if (tmp_blinded) bpf_jit_prog_release_other(prog, prog == orig_prog ? diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c009e472f647..883a35d50cd5 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -194,6 +194,7 @@ struct bpf_verifier_env { struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */ struct bpf_verifer_log log; u32 subprog_starts[BPF_MAX_SUBPROGS]; + /* computes the stack depth of each bpf function */ u16 subprog_stack_depth[BPF_MAX_SUBPROGS + 1]; u32 subprog_cnt; }; diff --git a/include/linux/filter.h b/include/linux/filter.h index e872b4ebaa57..2b0df2703671 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -18,6 +18,7 @@ #include #include #include +#include #include @@ -724,6 +725,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog); void bpf_jit_compile(struct bpf_prog *prog); bool bpf_helper_changes_pkt_data(void *func); +static inline bool bpf_dump_raw_ok(void) +{ + /* Reconstruction of call-sites is dependent on kallsyms, + * thus make dump the same restriction. + */ + return kallsyms_show_value() == 1; +} + struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, const struct bpf_insn *patch, u32 len); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d01f1cb3cfc0..69eabfcb9bdb 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1012,7 +1012,8 @@ struct bpf_perf_event_value { #define BPF_DEVCG_DEV_CHAR (1ULL << 1) struct bpf_cgroup_dev_ctx { - __u32 access_type; /* (access << 16) | type */ + /* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */ + __u32 access_type; __u32 major; __u32 minor; }; diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index b789ab78d28f..c1c0b60d3f2f 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -568,6 +568,8 @@ static bool cgroup_dev_is_valid_access(int off, int size, enum bpf_access_type type, struct bpf_insn_access_aux *info) { + const int size_default = sizeof(__u32); + if (type == BPF_WRITE) return false; @@ -576,8 +578,17 @@ static bool cgroup_dev_is_valid_access(int off, int size, /* The verifier guarantees that size > 0. */ if (off % size != 0) return false; - if (size != sizeof(__u32)) - return false; + + switch (off) { + case bpf_ctx_range(struct bpf_cgroup_dev_ctx, access_type): + bpf_ctx_record_field_size(info, size_default); + if (!bpf_ctx_narrow_access_ok(off, size, size_default)) + return false; + break; + default: + if (size != size_default) + return false; + } return true; } diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 768e0a02d8c8..70a534549cd3 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -771,7 +771,9 @@ struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog) /* Base function for offset calculation. Needs to go into .text section, * therefore keeping it non-static as well; will also be used by JITs - * anyway later on, so do not let the compiler omit it. + * anyway later on, so do not let the compiler omit it. This also needs + * to go into kallsyms for correlation from e.g. bpftool, so naming + * must not change. */ noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) { diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c index 883f88fa5bfc..8740406df2cd 100644 --- a/kernel/bpf/disasm.c +++ b/kernel/bpf/disasm.c @@ -21,10 +21,39 @@ static const char * const func_id_str[] = { }; #undef __BPF_FUNC_STR_FN -const char *func_id_name(int id) +static const char *__func_get_name(const struct bpf_insn_cbs *cbs, + const struct bpf_insn *insn, + char *buff, size_t len) { BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID); + if (insn->src_reg != BPF_PSEUDO_CALL && + insn->imm >= 0 && insn->imm < __BPF_FUNC_MAX_ID && + func_id_str[insn->imm]) + return func_id_str[insn->imm]; + + if (cbs && cbs->cb_call) + return cbs->cb_call(cbs->private_data, insn); + + if (insn->src_reg == BPF_PSEUDO_CALL) + snprintf(buff, len, "%+d", insn->imm); + + return buff; +} + +static const char *__func_imm_name(const struct bpf_insn_cbs *cbs, + const struct bpf_insn *insn, + u64 full_imm, char *buff, size_t len) +{ + if (cbs && cbs->cb_imm) + return cbs->cb_imm(cbs->private_data, insn, full_imm); + + snprintf(buff, len, "0x%llx", (unsigned long long)full_imm); + return buff; +} + +const char *func_id_name(int id) +{ if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id]) return func_id_str[id]; else @@ -83,7 +112,7 @@ static const char *const bpf_jmp_string[16] = { [BPF_EXIT >> 4] = "exit", }; -static void print_bpf_end_insn(bpf_insn_print_cb verbose, +static void print_bpf_end_insn(bpf_insn_print_t verbose, struct bpf_verifier_env *env, const struct bpf_insn *insn) { @@ -92,9 +121,12 @@ static void print_bpf_end_insn(bpf_insn_print_cb verbose, insn->imm, insn->dst_reg); } -void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env, - const struct bpf_insn *insn, bool allow_ptr_leaks) +void print_bpf_insn(const struct bpf_insn_cbs *cbs, + struct bpf_verifier_env *env, + const struct bpf_insn *insn, + bool allow_ptr_leaks) { + const bpf_insn_print_t verbose = cbs->cb_print; u8 class = BPF_CLASS(insn->code); if (class == BPF_ALU || class == BPF_ALU64) { @@ -175,12 +207,15 @@ void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env, */ u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; bool map_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD; + char tmp[64]; if (map_ptr && !allow_ptr_leaks) imm = 0; - verbose(env, "(%02x) r%d = 0x%llx\n", insn->code, - insn->dst_reg, (unsigned long long)imm); + verbose(env, "(%02x) r%d = %s\n", + insn->code, insn->dst_reg, + __func_imm_name(cbs, insn, imm, + tmp, sizeof(tmp))); } else { verbose(env, "BUG_ld_%02x\n", insn->code); return; @@ -189,12 +224,20 @@ void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env, u8 opcode = BPF_OP(insn->code); if (opcode == BPF_CALL) { - if (insn->src_reg == BPF_PSEUDO_CALL) - verbose(env, "(%02x) call pc%+d\n", insn->code, - insn->imm); - else + char tmp[64]; + + if (insn->src_reg == BPF_PSEUDO_CALL) { + verbose(env, "(%02x) call pc%s\n", + insn->code, + __func_get_name(cbs, insn, + tmp, sizeof(tmp))); + } else { + strcpy(tmp, "unknown"); verbose(env, "(%02x) call %s#%d\n", insn->code, - func_id_name(insn->imm), insn->imm); + __func_get_name(cbs, insn, + tmp, sizeof(tmp)), + insn->imm); + } } else if (insn->code == (BPF_JMP | BPF_JA)) { verbose(env, "(%02x) goto pc%+d\n", insn->code, insn->off); diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h index 8de977e420b6..e0857d016f89 100644 --- a/kernel/bpf/disasm.h +++ b/kernel/bpf/disasm.h @@ -17,16 +17,35 @@ #include #include #include +#ifndef __KERNEL__ +#include +#include +#endif + +struct bpf_verifier_env; extern const char *const bpf_alu_string[16]; extern const char *const bpf_class_string[8]; const char *func_id_name(int id); -struct bpf_verifier_env; -typedef void (*bpf_insn_print_cb)(struct bpf_verifier_env *env, - const char *, ...); -void print_bpf_insn(bpf_insn_print_cb verbose, struct bpf_verifier_env *env, - const struct bpf_insn *insn, bool allow_ptr_leaks); +typedef void (*bpf_insn_print_t)(struct bpf_verifier_env *env, + const char *, ...); +typedef const char *(*bpf_insn_revmap_call_t)(void *private_data, + const struct bpf_insn *insn); +typedef const char *(*bpf_insn_print_imm_t)(void *private_data, + const struct bpf_insn *insn, + __u64 full_imm); +struct bpf_insn_cbs { + bpf_insn_print_t cb_print; + bpf_insn_revmap_call_t cb_call; + bpf_insn_print_imm_t cb_imm; + void *private_data; +}; + +void print_bpf_insn(const struct bpf_insn_cbs *cbs, + struct bpf_verifier_env *env, + const struct bpf_insn *insn, + bool allow_ptr_leaks); #endif diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index e2e1c78ce1dc..007802c5ca7d 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -937,10 +937,16 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu) static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) { if (atomic_dec_and_test(&prog->aux->refcnt)) { + int i; + trace_bpf_prog_put_rcu(prog); /* bpf_prog_free_id() must be called first */ bpf_prog_free_id(prog, do_idr_lock); + + for (i = 0; i < prog->aux->func_cnt; i++) + bpf_prog_kallsyms_del(prog->aux->func[i]); bpf_prog_kallsyms_del(prog); + call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu); } } @@ -1552,6 +1558,67 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr) return fd; } +static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, + unsigned long addr) +{ + int i; + + for (i = 0; i < prog->aux->used_map_cnt; i++) + if (prog->aux->used_maps[i] == (void *)addr) + return prog->aux->used_maps[i]; + return NULL; +} + +static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog) +{ + const struct bpf_map *map; + struct bpf_insn *insns; + u64 imm; + int i; + + insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog), + GFP_USER); + if (!insns) + return insns; + + for (i = 0; i < prog->len; i++) { + if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) { + insns[i].code = BPF_JMP | BPF_CALL; + insns[i].imm = BPF_FUNC_tail_call; + /* fall-through */ + } + if (insns[i].code == (BPF_JMP | BPF_CALL) || + insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) { + if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) + insns[i].code = BPF_JMP | BPF_CALL; + if (!bpf_dump_raw_ok()) + insns[i].imm = 0; + continue; + } + + if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW)) + continue; + + imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm; + map = bpf_map_from_imm(prog, imm); + if (map) { + insns[i].src_reg = BPF_PSEUDO_MAP_FD; + insns[i].imm = map->id; + insns[i + 1].imm = 0; + continue; + } + + if (!bpf_dump_raw_ok() && + imm == (unsigned long)prog->aux) { + insns[i].imm = 0; + insns[i + 1].imm = 0; + continue; + } + } + + return insns; +} + static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, const union bpf_attr *attr, union bpf_attr __user *uattr) @@ -1602,18 +1669,34 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog, ulen = info.jited_prog_len; info.jited_prog_len = prog->jited_len; if (info.jited_prog_len && ulen) { - uinsns = u64_to_user_ptr(info.jited_prog_insns); - ulen = min_t(u32, info.jited_prog_len, ulen); - if (copy_to_user(uinsns, prog->bpf_func, ulen)) - return -EFAULT; + if (bpf_dump_raw_ok()) { + uinsns = u64_to_user_ptr(info.jited_prog_insns); + ulen = min_t(u32, info.jited_prog_len, ulen); + if (copy_to_user(uinsns, prog->bpf_func, ulen)) + return -EFAULT; + } else { + info.jited_prog_insns = 0; + } } ulen = info.xlated_prog_len; info.xlated_prog_len = bpf_prog_insn_size(prog); if (info.xlated_prog_len && ulen) { + struct bpf_insn *insns_sanitized; + bool fault; + + if (prog->blinded && !bpf_dump_raw_ok()) { + info.xlated_prog_insns = 0; + goto done; + } + insns_sanitized = bpf_insn_prepare_dump(prog); + if (!insns_sanitized) + return -ENOMEM; uinsns = u64_to_user_ptr(info.xlated_prog_insns); ulen = min_t(u32, info.xlated_prog_len, ulen); - if (copy_to_user(uinsns, prog->insnsi, ulen)) + fault = copy_to_user(uinsns, insns_sanitized, ulen); + kfree(insns_sanitized); + if (fault) return -EFAULT; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1cd2c2d28fc3..98d8637cf70d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -772,7 +772,7 @@ static int check_subprogs(struct bpf_verifier_env *env) return -EPERM; } if (bpf_prog_is_dev_bound(env->prog->aux)) { - verbose(env, "funcation calls in offloaded programs are not supported yet\n"); + verbose(env, "function calls in offloaded programs are not supported yet\n"); return -EINVAL; } ret = add_subprog(env, i + insn[i].imm + 1); @@ -823,6 +823,7 @@ next: return 0; } +static struct bpf_verifier_state *skip_callee(struct bpf_verifier_env *env, const struct bpf_verifier_state *state, struct bpf_verifier_state *parent, @@ -867,7 +868,7 @@ bug: verbose(env, "verifier bug regno %d tmp %p\n", regno, tmp); verbose(env, "regno %d parent frame %d current frame %d\n", regno, parent->curframe, state->curframe); - return 0; + return NULL; } static int mark_reg_read(struct bpf_verifier_env *env, @@ -1434,33 +1435,80 @@ static int update_stack_depth(struct bpf_verifier_env *env, const struct bpf_func_state *func, int off) { - u16 stack = env->subprog_stack_depth[func->subprogno], total = 0; - struct bpf_verifier_state *cur = env->cur_state; - int i; + u16 stack = env->subprog_stack_depth[func->subprogno]; if (stack >= -off) return 0; /* update known max for given subprogram */ env->subprog_stack_depth[func->subprogno] = -off; + return 0; +} - /* compute the total for current call chain */ - for (i = 0; i <= cur->curframe; i++) { - u32 depth = env->subprog_stack_depth[cur->frame[i]->subprogno]; +/* starting from main bpf function walk all instructions of the function + * and recursively walk all callees that given function can call. + * Ignore jump and exit insns. + * Since recursion is prevented by check_cfg() this algorithm + * only needs a local stack of MAX_CALL_FRAMES to remember callsites + */ +static int check_max_stack_depth(struct bpf_verifier_env *env) +{ + int depth = 0, frame = 0, subprog = 0, i = 0, subprog_end; + struct bpf_insn *insn = env->prog->insnsi; + int insn_cnt = env->prog->len; + int ret_insn[MAX_CALL_FRAMES]; + int ret_prog[MAX_CALL_FRAMES]; - /* round up to 32-bytes, since this is granularity - * of interpreter stack sizes - */ - depth = round_up(depth, 32); - total += depth; - } - - if (total > MAX_BPF_STACK) { +process_func: + /* round up to 32-bytes, since this is granularity + * of interpreter stack size + */ + depth += round_up(max_t(u32, env->subprog_stack_depth[subprog], 1), 32); + if (depth > MAX_BPF_STACK) { verbose(env, "combined stack size of %d calls is %d. Too large\n", - cur->curframe, total); + frame + 1, depth); return -EACCES; } - return 0; +continue_func: + if (env->subprog_cnt == subprog) + subprog_end = insn_cnt; + else + subprog_end = env->subprog_starts[subprog]; + for (; i < subprog_end; i++) { + if (insn[i].code != (BPF_JMP | BPF_CALL)) + continue; + if (insn[i].src_reg != BPF_PSEUDO_CALL) + continue; + /* remember insn and function to return to */ + ret_insn[frame] = i + 1; + ret_prog[frame] = subprog; + + /* find the callee */ + i = i + insn[i].imm + 1; + subprog = find_subprog(env, i); + if (subprog < 0) { + WARN_ONCE(1, "verifier bug. No program starts at insn %d\n", + i); + return -EFAULT; + } + subprog++; + frame++; + if (frame >= MAX_CALL_FRAMES) { + WARN_ONCE(1, "verifier bug. Call stack is too deep\n"); + return -EFAULT; + } + goto process_func; + } + /* end of for() loop means the last insn of the 'subprog' + * was reached. Doesn't matter whether it was JA or EXIT + */ + if (frame == 0) + return 0; + depth -= round_up(max_t(u32, env->subprog_stack_depth[subprog], 1), 32); + frame--; + i = ret_insn[frame]; + subprog = ret_prog[frame]; + goto continue_func; } static int get_callee_stack_depth(struct bpf_verifier_env *env, @@ -2105,9 +2153,9 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn, struct bpf_func_state *caller, *callee; int i, subprog, target_insn; - if (state->curframe >= MAX_CALL_FRAMES) { + if (state->curframe + 1 >= MAX_CALL_FRAMES) { verbose(env, "the call stack of %d frames is too deep\n", - state->curframe); + state->curframe + 2); return -E2BIG; } @@ -4155,7 +4203,7 @@ static bool stacksafe(struct bpf_func_state *old, if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)) /* explored state didn't use this */ - return true; + continue; if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID) continue; @@ -4475,9 +4523,12 @@ static int do_check(struct bpf_verifier_env *env) } if (env->log.level) { + const struct bpf_insn_cbs cbs = { + .cb_print = verbose, + }; + verbose(env, "%d: ", insn_idx); - print_bpf_insn(verbose, env, insn, - env->allow_ptr_leaks); + print_bpf_insn(&cbs, env, insn, env->allow_ptr_leaks); } err = ext_analyzer_insn_hook(env, insn_idx, prev_insn_idx); @@ -5065,14 +5116,14 @@ static int jit_subprogs(struct bpf_verifier_env *env) { struct bpf_prog *prog = env->prog, **func, *tmp; int i, j, subprog_start, subprog_end = 0, len, subprog; - struct bpf_insn *insn = prog->insnsi; + struct bpf_insn *insn; void *old_bpf_func; int err = -ENOMEM; if (env->subprog_cnt == 0) return 0; - for (i = 0; i < prog->len; i++, insn++) { + for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) { if (insn->code != (BPF_JMP | BPF_CALL) || insn->src_reg != BPF_PSEUDO_CALL) continue; @@ -5111,7 +5162,10 @@ static int jit_subprogs(struct bpf_verifier_env *env) goto out_free; memcpy(func[i]->insnsi, &prog->insnsi[subprog_start], len * sizeof(struct bpf_insn)); + func[i]->type = prog->type; func[i]->len = len; + if (bpf_prog_calc_tag(func[i])) + goto out_free; func[i]->is_func = 1; /* Use bpf_prog_F_tag to indicate functions in stack traces. * Long term would need debug info to populate names @@ -5161,6 +5215,25 @@ static int jit_subprogs(struct bpf_verifier_env *env) bpf_prog_lock_ro(func[i]); bpf_prog_kallsyms_add(func[i]); } + + /* Last step: make now unused interpreter insns from main + * prog consistent for later dump requests, so they can + * later look the same as if they were interpreted only. + */ + for (i = 0, insn = prog->insnsi; i < prog->len; i++, insn++) { + unsigned long addr; + + if (insn->code != (BPF_JMP | BPF_CALL) || + insn->src_reg != BPF_PSEUDO_CALL) + continue; + insn->off = env->insn_aux_data[i].call_imm; + subprog = find_subprog(env, i + insn->off + 1); + addr = (unsigned long)func[subprog + 1]->bpf_func; + addr &= PAGE_MASK; + insn->imm = (u64 (*)(u64, u64, u64, u64, u64)) + addr - __bpf_call_base; + } + prog->jited = 1; prog->bpf_func = func[0]->bpf_func; prog->aux->func = func; @@ -5426,6 +5499,9 @@ skip_full_check: if (ret == 0) sanitize_dead_code(env); + if (ret == 0) + ret = check_max_stack_depth(env); + if (ret == 0) /* program is valid, convert *(u32*)(ctx + off) accesses */ ret = convert_ctx_accesses(env); diff --git a/net/core/filter.c b/net/core/filter.c index 754abe1041b7..130b842c3a15 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2684,8 +2684,9 @@ static int __xdp_generic_ok_fwd_dev(struct sk_buff *skb, struct net_device *fwd) return 0; } -int xdp_do_generic_redirect_map(struct net_device *dev, struct sk_buff *skb, - struct bpf_prog *xdp_prog) +static int xdp_do_generic_redirect_map(struct net_device *dev, + struct sk_buff *skb, + struct bpf_prog *xdp_prog) { struct redirect_info *ri = this_cpu_ptr(&redirect_info); unsigned long map_owner = ri->map_owner; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 037484ceaeaf..42ee8892549c 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -401,6 +401,88 @@ static int do_show(int argc, char **argv) return err; } +#define SYM_MAX_NAME 256 + +struct kernel_sym { + unsigned long address; + char name[SYM_MAX_NAME]; +}; + +struct dump_data { + unsigned long address_call_base; + struct kernel_sym *sym_mapping; + __u32 sym_count; + char scratch_buff[SYM_MAX_NAME]; +}; + +static int kernel_syms_cmp(const void *sym_a, const void *sym_b) +{ + return ((struct kernel_sym *)sym_a)->address - + ((struct kernel_sym *)sym_b)->address; +} + +static void kernel_syms_load(struct dump_data *dd) +{ + struct kernel_sym *sym; + char buff[256]; + void *tmp, *address; + FILE *fp; + + fp = fopen("/proc/kallsyms", "r"); + if (!fp) + return; + + while (!feof(fp)) { + if (!fgets(buff, sizeof(buff), fp)) + break; + tmp = realloc(dd->sym_mapping, + (dd->sym_count + 1) * + sizeof(*dd->sym_mapping)); + if (!tmp) { +out: + free(dd->sym_mapping); + dd->sym_mapping = NULL; + fclose(fp); + return; + } + dd->sym_mapping = tmp; + sym = &dd->sym_mapping[dd->sym_count]; + if (sscanf(buff, "%p %*c %s", &address, sym->name) != 2) + continue; + sym->address = (unsigned long)address; + if (!strcmp(sym->name, "__bpf_call_base")) { + dd->address_call_base = sym->address; + /* sysctl kernel.kptr_restrict was set */ + if (!sym->address) + goto out; + } + if (sym->address) + dd->sym_count++; + } + + fclose(fp); + + qsort(dd->sym_mapping, dd->sym_count, + sizeof(*dd->sym_mapping), kernel_syms_cmp); +} + +static void kernel_syms_destroy(struct dump_data *dd) +{ + free(dd->sym_mapping); +} + +static struct kernel_sym *kernel_syms_search(struct dump_data *dd, + unsigned long key) +{ + struct kernel_sym sym = { + .address = key, + }; + + return dd->sym_mapping ? + bsearch(&sym, dd->sym_mapping, dd->sym_count, + sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL; +} + static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) { va_list args; @@ -410,8 +492,71 @@ static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) va_end(args); } -static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes) +static const char *print_call_pcrel(struct dump_data *dd, + struct kernel_sym *sym, + unsigned long address, + const struct bpf_insn *insn) { + if (sym) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d#%s", insn->off, sym->name); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d#0x%lx", insn->off, address); + return dd->scratch_buff; +} + +static const char *print_call_helper(struct dump_data *dd, + struct kernel_sym *sym, + unsigned long address) +{ + if (sym) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%s", sym->name); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "0x%lx", address); + return dd->scratch_buff; +} + +static const char *print_call(void *private_data, + const struct bpf_insn *insn) +{ + struct dump_data *dd = private_data; + unsigned long address = dd->address_call_base + insn->imm; + struct kernel_sym *sym; + + sym = kernel_syms_search(dd, address); + if (insn->src_reg == BPF_PSEUDO_CALL) + return print_call_pcrel(dd, sym, address, insn); + else + return print_call_helper(dd, sym, address); +} + +static const char *print_imm(void *private_data, + const struct bpf_insn *insn, + __u64 full_imm) +{ + struct dump_data *dd = private_data; + + if (insn->src_reg == BPF_PSEUDO_MAP_FD) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "map[id:%u]", insn->imm); + else + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "0x%llx", (unsigned long long)full_imm); + return dd->scratch_buff; +} + +static void dump_xlated_plain(struct dump_data *dd, void *buf, + unsigned int len, bool opcodes) +{ + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; struct bpf_insn *insn = buf; bool double_insn = false; unsigned int i; @@ -425,7 +570,7 @@ static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes) double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); printf("% 4d: ", i); - print_bpf_insn(print_insn, NULL, insn + i, true); + print_bpf_insn(&cbs, NULL, insn + i, true); if (opcodes) { printf(" "); @@ -454,8 +599,15 @@ static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...) va_end(args); } -static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) +static void dump_xlated_json(struct dump_data *dd, void *buf, + unsigned int len, bool opcodes) { + const struct bpf_insn_cbs cbs = { + .cb_print = print_insn_json, + .cb_call = print_call, + .cb_imm = print_imm, + .private_data = dd, + }; struct bpf_insn *insn = buf; bool double_insn = false; unsigned int i; @@ -470,7 +622,7 @@ static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) jsonw_start_object(json_wtr); jsonw_name(json_wtr, "disasm"); - print_bpf_insn(print_insn_json, NULL, insn + i, true); + print_bpf_insn(&cbs, NULL, insn + i, true); if (opcodes) { jsonw_name(json_wtr, "opcodes"); @@ -505,6 +657,7 @@ static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) static int do_dump(int argc, char **argv) { struct bpf_prog_info info = {}; + struct dump_data dd = {}; __u32 len = sizeof(info); unsigned int buf_size; char *filepath = NULL; @@ -592,6 +745,14 @@ static int do_dump(int argc, char **argv) goto err_free; } + if ((member_len == &info.jited_prog_len && + info.jited_prog_insns == 0) || + (member_len == &info.xlated_prog_len && + info.xlated_prog_insns == 0)) { + p_err("error retrieving insn dump: kernel.kptr_restrict set?"); + goto err_free; + } + if (filepath) { fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd < 0) { @@ -608,17 +769,19 @@ static int do_dump(int argc, char **argv) goto err_free; } } else { - if (member_len == &info.jited_prog_len) + if (member_len == &info.jited_prog_len) { disasm_print_insn(buf, *member_len, opcodes); - else + } else { + kernel_syms_load(&dd); if (json_output) - dump_xlated_json(buf, *member_len, opcodes); + dump_xlated_json(&dd, buf, *member_len, opcodes); else - dump_xlated_plain(buf, *member_len, opcodes); + dump_xlated_plain(&dd, buf, *member_len, opcodes); + kernel_syms_destroy(&dd); + } } free(buf); - return 0; err_free: diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 5b83875b3594..e9c4b7cabcf2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -910,8 +910,9 @@ bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr, GELF_R_SYM(rel.r_info)); return -LIBBPF_ERRNO__FORMAT; } - pr_debug("relo for %ld value %ld name %d\n", - rel.r_info >> 32, sym.st_value, sym.st_name); + pr_debug("relo for %lld value %lld name %d\n", + (long long) (rel.r_info >> 32), + (long long) sym.st_value, sym.st_name); if (sym.st_shndx != maps_shndx && sym.st_shndx != text_shndx) { pr_warning("Program '%s' contains non-map related relo data pointing to section %u\n", diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index 9d4897317c77..983dd25d49f4 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -4,3 +4,4 @@ CONFIG_NET_CLS_BPF=m CONFIG_BPF_EVENTS=y CONFIG_TEST_BPF=m CONFIG_CGROUP_BPF=y +CONFIG_NETDEVSIM=m diff --git a/tools/testing/selftests/bpf/test_dev_cgroup.c b/tools/testing/selftests/bpf/test_dev_cgroup.c index 02c85d6c89b0..c1535b34f14f 100644 --- a/tools/testing/selftests/bpf/test_dev_cgroup.c +++ b/tools/testing/selftests/bpf/test_dev_cgroup.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include #include #include @@ -23,15 +25,19 @@ int main(int argc, char **argv) { + struct rlimit limit = { RLIM_INFINITY, RLIM_INFINITY }; struct bpf_object *obj; int error = EXIT_FAILURE; int prog_fd, cgroup_fd; __u32 prog_cnt; + if (setrlimit(RLIMIT_MEMLOCK, &limit) < 0) + perror("Unable to lift memlock rlimit"); + if (bpf_prog_load(DEV_CGROUP_PROG, BPF_PROG_TYPE_CGROUP_DEVICE, &obj, &prog_fd)) { printf("Failed to load DEV_CGROUP program\n"); - goto err; + goto out; } if (setup_cgroup_environment()) { @@ -89,5 +95,6 @@ int main(int argc, char **argv) err: cleanup_cgroup_environment(); +out: return error; } diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index d38334abb990..543847957fdd 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -9272,6 +9272,196 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_XDP, .result = ACCEPT, }, + { + "calls: stack overflow using two frames (pre-call access)", + .insns = { + /* prog 1 */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), + BPF_EXIT_INSN(), + + /* prog 2 */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .errstr = "combined stack size", + .result = REJECT, + }, + { + "calls: stack overflow using two frames (post-call access)", + .insns = { + /* prog 1 */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 2), + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_EXIT_INSN(), + + /* prog 2 */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .errstr = "combined stack size", + .result = REJECT, + }, + { + "calls: stack depth check using three frames. test1", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 4), /* call A */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 5), /* call B */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -32, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -256, 0), + BPF_EXIT_INSN(), + /* B */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, -3), /* call A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -64, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + /* stack_main=32, stack_A=256, stack_B=64 + * and max(main+A, main+A+B) < 512 + */ + .result = ACCEPT, + }, + { + "calls: stack depth check using three frames. test2", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 4), /* call A */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 5), /* call B */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -32, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -64, 0), + BPF_EXIT_INSN(), + /* B */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, -3), /* call A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -256, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + /* stack_main=32, stack_A=64, stack_B=256 + * and max(main+A, main+A+B) < 512 + */ + .result = ACCEPT, + }, + { + "calls: stack depth check using three frames. test3", + .insns = { + /* main */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 6), /* call A */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 8), /* call B */ + BPF_JMP_IMM(BPF_JGE, BPF_REG_6, 0, 1), + BPF_ST_MEM(BPF_B, BPF_REG_10, -64, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_JMP_IMM(BPF_JLT, BPF_REG_1, 10, 1), + BPF_EXIT_INSN(), + BPF_ST_MEM(BPF_B, BPF_REG_10, -224, 0), + BPF_JMP_IMM(BPF_JA, 0, 0, -3), + /* B */ + BPF_JMP_IMM(BPF_JGT, BPF_REG_1, 2, 1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, -6), /* call A */ + BPF_ST_MEM(BPF_B, BPF_REG_10, -256, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + /* stack_main=64, stack_A=224, stack_B=256 + * and max(main+A, main+A+B) > 512 + */ + .errstr = "combined stack", + .result = REJECT, + }, + { + "calls: stack depth check using three frames. test4", + /* void main(void) { + * func1(0); + * func1(1); + * func2(1); + * } + * void func1(int alloc_or_recurse) { + * if (alloc_or_recurse) { + * frame_pointer[-300] = 1; + * } else { + * func2(alloc_or_recurse); + * } + * } + * void func2(int alloc_or_recurse) { + * if (alloc_or_recurse) { + * frame_pointer[-300] = 1; + * } + * } + */ + .insns = { + /* main */ + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 6), /* call A */ + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 4), /* call A */ + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 7), /* call B */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* A */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 2), + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_EXIT_INSN(), + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call B */ + BPF_EXIT_INSN(), + /* B */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_ST_MEM(BPF_B, BPF_REG_10, -300, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .result = REJECT, + .errstr = "combined stack", + }, + { + "calls: stack depth check using three frames. test5", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call A */ + BPF_EXIT_INSN(), + /* A */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call B */ + BPF_EXIT_INSN(), + /* B */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call C */ + BPF_EXIT_INSN(), + /* C */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call D */ + BPF_EXIT_INSN(), + /* D */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call E */ + BPF_EXIT_INSN(), + /* E */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call F */ + BPF_EXIT_INSN(), + /* F */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call G */ + BPF_EXIT_INSN(), + /* G */ + BPF_RAW_INSN(BPF_JMP|BPF_CALL, 0, 1, 0, 1), /* call H */ + BPF_EXIT_INSN(), + /* H */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_XDP, + .errstr = "call stack", + .result = REJECT, + }, { "calls: spill into caller stack frame", .insns = { @@ -10258,6 +10448,57 @@ static struct bpf_test tests[] = { .result = REJECT, .prog_type = BPF_PROG_TYPE_XDP, }, + { + "search pruning: all branches should be verified (nop operation)", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 11), + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0xbeef, 2), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_JMP_A(1), + BPF_MOV64_IMM(BPF_REG_4, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -16), + BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns), + BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -16), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_5, 0, 2), + BPF_MOV64_IMM(BPF_REG_6, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_6, 0, 0xdead), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 3 }, + .errstr = "R6 invalid mem access 'inv'", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + }, + { + "search pruning: all branches should be verified (invalid stack access)", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8), + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0xbeef, 2), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -16), + BPF_JMP_A(1), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -24), + BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns), + BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -16), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 3 }, + .errstr = "invalid read from stack off -16+0 size 8", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + }, }; static int probe_filter_length(const struct bpf_insn *fp)