diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-12-14 12:58:14 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-12-14 12:58:14 -0800 |
commit | 35f301dd4551fa731db4834f915e8351838f6f19 (patch) | |
tree | ef5cf8899f05360f35b4b8c370bd5366014357be /kernel | |
parent | a0e3919a2df29b373b19a8fbd6e4c4c38fc10d87 (diff) | |
parent | c83508da5620ef89232cb614fb9e02dfdfef2b8f (diff) |
Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Daniel Borkmann:
- Fix a bug in the BPF verifier to track changes to packet data
property for global functions (Eduard Zingerman)
- Fix a theoretical BPF prog_array use-after-free in RCU handling of
__uprobe_perf_func (Jann Horn)
- Fix BPF tracing to have an explicit list of tracepoints and their
arguments which need to be annotated as PTR_MAYBE_NULL (Kumar
Kartikeya Dwivedi)
- Fix a logic bug in the bpf_remove_insns code where a potential error
would have been wrongly propagated (Anton Protopopov)
- Avoid deadlock scenarios caused by nested kprobe and fentry BPF
programs (Priya Bala Govindasamy)
- Fix a bug in BPF verifier which was missing a size check for
BTF-based context access (Kumar Kartikeya Dwivedi)
- Fix a crash found by syzbot through an invalid BPF prog_array access
in perf_event_detach_bpf_prog (Jiri Olsa)
- Fix several BPF sockmap bugs including a race causing a refcount
imbalance upon element replace (Michal Luczaj)
- Fix a use-after-free from mismatching BPF program/attachment RCU
flavors (Jann Horn)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (23 commits)
bpf: Avoid deadlock caused by nested kprobe and fentry bpf programs
selftests/bpf: Add tests for raw_tp NULL args
bpf: Augment raw_tp arguments with PTR_MAYBE_NULL
bpf: Revert "bpf: Mark raw_tp arguments with PTR_MAYBE_NULL"
selftests/bpf: Add test for narrow ctx load for pointer args
bpf: Check size for BTF-based ctx access of pointer members
selftests/bpf: extend changes_pkt_data with cases w/o subprograms
bpf: fix null dereference when computing changes_pkt_data of prog w/o subprogs
bpf: Fix theoretical prog_array UAF in __uprobe_perf_func()
bpf: fix potential error return
selftests/bpf: validate that tail call invalidates packet pointers
bpf: consider that tail calls invalidate packet pointers
selftests/bpf: freplace tests for tracking of changes_packet_data
bpf: check changes_pkt_data property for extension programs
selftests/bpf: test for changing packet data from global functions
bpf: track changes_pkt_data property for global functions
bpf: refactor bpf_helper_changes_pkt_data to use helper number
bpf: add find_containing_subprog() utility function
bpf,perf: Fix invalid prog_array access in perf_event_detach_bpf_prog
bpf: Fix UAF via mismatching bpf_prog/attachment RCU flavors
...
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/bpf/Makefile | 6 | ||||
-rw-r--r-- | kernel/bpf/btf.c | 149 | ||||
-rw-r--r-- | kernel/bpf/core.c | 8 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 160 | ||||
-rw-r--r-- | kernel/trace/bpf_trace.c | 11 | ||||
-rw-r--r-- | kernel/trace/trace_uprobe.c | 6 |
6 files changed, 251 insertions, 89 deletions
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 9762bdddf1de..410028633621 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -53,3 +53,9 @@ obj-$(CONFIG_BPF_SYSCALL) += relo_core.o obj-$(CONFIG_BPF_SYSCALL) += btf_iter.o obj-$(CONFIG_BPF_SYSCALL) += btf_relocate.o obj-$(CONFIG_BPF_SYSCALL) += kmem_cache_iter.o + +CFLAGS_REMOVE_percpu_freelist.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_bpf_lru_list.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_queue_stack_maps.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_lpm_trie.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_ringbuf.o = $(CC_FLAGS_FTRACE) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index e7a59e6462a9..e5a5f023cedd 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6439,6 +6439,101 @@ int btf_ctx_arg_offset(const struct btf *btf, const struct btf_type *func_proto, return off; } +struct bpf_raw_tp_null_args { + const char *func; + u64 mask; +}; + +static const struct bpf_raw_tp_null_args raw_tp_null_args[] = { + /* sched */ + { "sched_pi_setprio", 0x10 }, + /* ... from sched_numa_pair_template event class */ + { "sched_stick_numa", 0x100 }, + { "sched_swap_numa", 0x100 }, + /* afs */ + { "afs_make_fs_call", 0x10 }, + { "afs_make_fs_calli", 0x10 }, + { "afs_make_fs_call1", 0x10 }, + { "afs_make_fs_call2", 0x10 }, + { "afs_protocol_error", 0x1 }, + { "afs_flock_ev", 0x10 }, + /* cachefiles */ + { "cachefiles_lookup", 0x1 | 0x200 }, + { "cachefiles_unlink", 0x1 }, + { "cachefiles_rename", 0x1 }, + { "cachefiles_prep_read", 0x1 }, + { "cachefiles_mark_active", 0x1 }, + { "cachefiles_mark_failed", 0x1 }, + { "cachefiles_mark_inactive", 0x1 }, + { "cachefiles_vfs_error", 0x1 }, + { "cachefiles_io_error", 0x1 }, + { "cachefiles_ondemand_open", 0x1 }, + { "cachefiles_ondemand_copen", 0x1 }, + { "cachefiles_ondemand_close", 0x1 }, + { "cachefiles_ondemand_read", 0x1 }, + { "cachefiles_ondemand_cread", 0x1 }, + { "cachefiles_ondemand_fd_write", 0x1 }, + { "cachefiles_ondemand_fd_release", 0x1 }, + /* ext4, from ext4__mballoc event class */ + { "ext4_mballoc_discard", 0x10 }, + { "ext4_mballoc_free", 0x10 }, + /* fib */ + { "fib_table_lookup", 0x100 }, + /* filelock */ + /* ... from filelock_lock event class */ + { "posix_lock_inode", 0x10 }, + { "fcntl_setlk", 0x10 }, + { "locks_remove_posix", 0x10 }, + { "flock_lock_inode", 0x10 }, + /* ... from filelock_lease event class */ + { "break_lease_noblock", 0x10 }, + { "break_lease_block", 0x10 }, + { "break_lease_unblock", 0x10 }, + { "generic_delete_lease", 0x10 }, + { "time_out_leases", 0x10 }, + /* host1x */ + { "host1x_cdma_push_gather", 0x10000 }, + /* huge_memory */ + { "mm_khugepaged_scan_pmd", 0x10 }, + { "mm_collapse_huge_page_isolate", 0x1 }, + { "mm_khugepaged_scan_file", 0x10 }, + { "mm_khugepaged_collapse_file", 0x10 }, + /* kmem */ + { "mm_page_alloc", 0x1 }, + { "mm_page_pcpu_drain", 0x1 }, + /* .. from mm_page event class */ + { "mm_page_alloc_zone_locked", 0x1 }, + /* netfs */ + { "netfs_failure", 0x10 }, + /* power */ + { "device_pm_callback_start", 0x10 }, + /* qdisc */ + { "qdisc_dequeue", 0x1000 }, + /* rxrpc */ + { "rxrpc_recvdata", 0x1 }, + { "rxrpc_resend", 0x10 }, + /* sunrpc */ + { "xs_stream_read_data", 0x1 }, + /* ... from xprt_cong_event event class */ + { "xprt_reserve_cong", 0x10 }, + { "xprt_release_cong", 0x10 }, + { "xprt_get_cong", 0x10 }, + { "xprt_put_cong", 0x10 }, + /* tcp */ + { "tcp_send_reset", 0x11 }, + /* tegra_apb_dma */ + { "tegra_dma_tx_status", 0x100 }, + /* timer_migration */ + { "tmigr_update_events", 0x1 }, + /* writeback, from writeback_folio_template event class */ + { "writeback_dirty_folio", 0x10 }, + { "folio_wait_writeback", 0x10 }, + /* rdma */ + { "mr_integ_alloc", 0x2000 }, + /* bpf_testmod */ + { "bpf_testmod_test_read", 0x0 }, +}; + bool btf_ctx_access(int off, int size, enum bpf_access_type type, const struct bpf_prog *prog, struct bpf_insn_access_aux *info) @@ -6449,6 +6544,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, const char *tname = prog->aux->attach_func_name; struct bpf_verifier_log *log = info->log; const struct btf_param *args; + bool ptr_err_raw_tp = false; const char *tag_value; u32 nr_args, arg; int i, ret; @@ -6543,6 +6639,12 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, return false; } + if (size != sizeof(u64)) { + bpf_log(log, "func '%s' size %d must be 8\n", + tname, size); + return false; + } + /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; @@ -6588,12 +6690,42 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, if (prog_args_trusted(prog)) info->reg_type |= PTR_TRUSTED; - /* Raw tracepoint arguments always get marked as maybe NULL */ - if (bpf_prog_is_raw_tp(prog)) - info->reg_type |= PTR_MAYBE_NULL; - else if (btf_param_match_suffix(btf, &args[arg], "__nullable")) + if (btf_param_match_suffix(btf, &args[arg], "__nullable")) info->reg_type |= PTR_MAYBE_NULL; + if (prog->expected_attach_type == BPF_TRACE_RAW_TP) { + struct btf *btf = prog->aux->attach_btf; + const struct btf_type *t; + const char *tname; + + /* BTF lookups cannot fail, return false on error */ + t = btf_type_by_id(btf, prog->aux->attach_btf_id); + if (!t) + return false; + tname = btf_name_by_offset(btf, t->name_off); + if (!tname) + return false; + /* Checked by bpf_check_attach_target */ + tname += sizeof("btf_trace_") - 1; + for (i = 0; i < ARRAY_SIZE(raw_tp_null_args); i++) { + /* Is this a func with potential NULL args? */ + if (strcmp(tname, raw_tp_null_args[i].func)) + continue; + if (raw_tp_null_args[i].mask & (0x1 << (arg * 4))) + info->reg_type |= PTR_MAYBE_NULL; + /* Is the current arg IS_ERR? */ + if (raw_tp_null_args[i].mask & (0x2 << (arg * 4))) + ptr_err_raw_tp = true; + break; + } + /* If we don't know NULL-ness specification and the tracepoint + * is coming from a loadable module, be conservative and mark + * argument as PTR_MAYBE_NULL. + */ + if (i == ARRAY_SIZE(raw_tp_null_args) && btf_is_module(btf)) + info->reg_type |= PTR_MAYBE_NULL; + } + if (tgt_prog) { enum bpf_prog_type tgt_type; @@ -6638,6 +6770,15 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", tname, arg, info->btf_id, btf_type_str(t), __btf_name_by_offset(btf, t->name_off)); + + /* Perform all checks on the validity of type for this argument, but if + * we know it can be IS_ERR at runtime, scrub pointer type and mark as + * scalar. + */ + if (ptr_err_raw_tp) { + bpf_log(log, "marking pointer arg%d as scalar as it may encode error", arg); + info->reg_type = SCALAR_VALUE; + } return true; } EXPORT_SYMBOL_GPL(btf_ctx_access); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index a2327c4fdc8b..da729cbbaeb9 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -539,6 +539,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) { + int err; + /* Branch offsets can't overflow when program is shrinking, no need * to call bpf_adj_branches(..., true) here */ @@ -546,7 +548,9 @@ int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) sizeof(struct bpf_insn) * (prog->len - off - cnt)); prog->len -= cnt; - return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); + err = bpf_adj_branches(prog, off, off + cnt, off, false); + WARN_ON_ONCE(err); + return err; } static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) @@ -2936,7 +2940,7 @@ void __weak bpf_jit_compile(struct bpf_prog *prog) { } -bool __weak bpf_helper_changes_pkt_data(void *func) +bool __weak bpf_helper_changes_pkt_data(enum bpf_func_id func_id) { return false; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 01fbef9576e0..f7f892a52a37 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -420,25 +420,6 @@ static struct btf_record *reg_btf_record(const struct bpf_reg_state *reg) return rec; } -static bool mask_raw_tp_reg_cond(const struct bpf_verifier_env *env, struct bpf_reg_state *reg) { - return reg->type == (PTR_TO_BTF_ID | PTR_TRUSTED | PTR_MAYBE_NULL) && - bpf_prog_is_raw_tp(env->prog) && !reg->ref_obj_id; -} - -static bool mask_raw_tp_reg(const struct bpf_verifier_env *env, struct bpf_reg_state *reg) -{ - if (!mask_raw_tp_reg_cond(env, reg)) - return false; - reg->type &= ~PTR_MAYBE_NULL; - return true; -} - -static void unmask_raw_tp_reg(struct bpf_reg_state *reg, bool result) -{ - if (result) - reg->type |= PTR_MAYBE_NULL; -} - static bool subprog_is_global(const struct bpf_verifier_env *env, int subprog) { struct bpf_func_info_aux *aux = env->prog->aux->func_info_aux; @@ -2597,16 +2578,36 @@ static int cmp_subprogs(const void *a, const void *b) ((struct bpf_subprog_info *)b)->start; } +/* Find subprogram that contains instruction at 'off' */ +static struct bpf_subprog_info *find_containing_subprog(struct bpf_verifier_env *env, int off) +{ + struct bpf_subprog_info *vals = env->subprog_info; + int l, r, m; + + if (off >= env->prog->len || off < 0 || env->subprog_cnt == 0) + return NULL; + + l = 0; + r = env->subprog_cnt - 1; + while (l < r) { + m = l + (r - l + 1) / 2; + if (vals[m].start <= off) + l = m; + else + r = m - 1; + } + return &vals[l]; +} + +/* Find subprogram that starts exactly at 'off' */ static int find_subprog(struct bpf_verifier_env *env, int off) { struct bpf_subprog_info *p; - p = bsearch(&off, env->subprog_info, env->subprog_cnt, - sizeof(env->subprog_info[0]), cmp_subprogs); - if (!p) + p = find_containing_subprog(env, off); + if (!p || p->start != off) return -ENOENT; return p - env->subprog_info; - } static int add_subprog(struct bpf_verifier_env *env, int off) @@ -6781,7 +6782,6 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, const char *field_name = NULL; enum bpf_type_flag flag = 0; u32 btf_id = 0; - bool mask; int ret; if (!env->allow_ptr_leaks) { @@ -6853,21 +6853,7 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, if (ret < 0) return ret; - /* For raw_tp progs, we allow dereference of PTR_MAYBE_NULL - * trusted PTR_TO_BTF_ID, these are the ones that are possibly - * arguments to the raw_tp. Since internal checks in for trusted - * reg in check_ptr_to_btf_access would consider PTR_MAYBE_NULL - * modifier as problematic, mask it out temporarily for the - * check. Don't apply this to pointers with ref_obj_id > 0, as - * those won't be raw_tp args. - * - * We may end up applying this relaxation to other trusted - * PTR_TO_BTF_ID with maybe null flag, since we cannot - * distinguish PTR_MAYBE_NULL tagged for arguments vs normal - * tagging, but that should expand allowed behavior, and not - * cause regression for existing behavior. - */ - mask = mask_raw_tp_reg(env, reg); + if (ret != PTR_TO_BTF_ID) { /* just mark; */ @@ -6928,13 +6914,8 @@ static int check_ptr_to_btf_access(struct bpf_verifier_env *env, clear_trusted_flags(&flag); } - if (atype == BPF_READ && value_regno >= 0) { + if (atype == BPF_READ && value_regno >= 0) mark_btf_ld_reg(env, regs, value_regno, ret, reg->btf, btf_id, flag); - /* We've assigned a new type to regno, so don't undo masking. */ - if (regno == value_regno) - mask = false; - } - unmask_raw_tp_reg(reg, mask); return 0; } @@ -7309,7 +7290,7 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn if (!err && t == BPF_READ && value_regno >= 0) mark_reg_unknown(env, regs, value_regno); } else if (base_type(reg->type) == PTR_TO_BTF_ID && - (mask_raw_tp_reg_cond(env, reg) || !type_may_be_null(reg->type))) { + !type_may_be_null(reg->type)) { err = check_ptr_to_btf_access(env, regs, regno, off, size, t, value_regno); } else if (reg->type == CONST_PTR_TO_MAP) { @@ -9012,7 +8993,6 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, enum bpf_reg_type type = reg->type; u32 *arg_btf_id = NULL; int err = 0; - bool mask; if (arg_type == ARG_DONTCARE) return 0; @@ -9053,11 +9033,11 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, base_type(arg_type) == ARG_PTR_TO_SPIN_LOCK) arg_btf_id = fn->arg_btf_id[arg]; - mask = mask_raw_tp_reg(env, reg); err = check_reg_type(env, regno, arg_type, arg_btf_id, meta); + if (err) + return err; - err = err ?: check_func_arg_reg_off(env, reg, regno, arg_type); - unmask_raw_tp_reg(reg, mask); + err = check_func_arg_reg_off(env, reg, regno, arg_type); if (err) return err; @@ -9852,17 +9832,14 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog, return ret; } else if (base_type(arg->arg_type) == ARG_PTR_TO_BTF_ID) { struct bpf_call_arg_meta meta; - bool mask; int err; if (register_is_null(reg) && type_may_be_null(arg->arg_type)) continue; memset(&meta, 0, sizeof(meta)); /* leave func_id as zero */ - mask = mask_raw_tp_reg(env, reg); err = check_reg_type(env, regno, arg->arg_type, &arg->btf_id, &meta); err = err ?: check_func_arg_reg_off(env, reg, regno, arg->arg_type); - unmask_raw_tp_reg(reg, mask); if (err) return err; } else { @@ -10022,6 +9999,8 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn, verbose(env, "Func#%d ('%s') is global and assumed valid.\n", subprog, sub_name); + if (env->subprog_info[subprog].changes_pkt_data) + clear_all_pkt_pointers(env); /* mark global subprog for verifying after main prog */ subprog_aux(env, subprog)->called = true; clear_caller_saved_regs(env, caller->regs); @@ -10708,7 +10687,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn } /* With LD_ABS/IND some JITs save/restore skb from r1. */ - changes_data = bpf_helper_changes_pkt_data(fn->func); + changes_data = bpf_helper_changes_pkt_data(func_id); if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) { verbose(env, "kernel subsystem misconfigured func %s#%d: r1 != ctx\n", func_id_name(func_id), func_id); @@ -12183,7 +12162,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ enum bpf_arg_type arg_type = ARG_DONTCARE; u32 regno = i + 1, ref_id, type_size; bool is_ret_buf_sz = false; - bool mask = false; int kf_arg_type; t = btf_type_skip_modifiers(btf, args[i].type, NULL); @@ -12242,15 +12220,12 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ return -EINVAL; } - mask = mask_raw_tp_reg(env, reg); if ((is_kfunc_trusted_args(meta) || is_kfunc_rcu(meta)) && (register_is_null(reg) || type_may_be_null(reg->type)) && !is_kfunc_arg_nullable(meta->btf, &args[i])) { verbose(env, "Possibly NULL pointer passed to trusted arg%d\n", i); - unmask_raw_tp_reg(reg, mask); return -EACCES; } - unmask_raw_tp_reg(reg, mask); if (reg->ref_obj_id) { if (is_kfunc_release(meta) && meta->ref_obj_id) { @@ -12308,24 +12283,16 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ if (!is_kfunc_trusted_args(meta) && !is_kfunc_rcu(meta)) break; - /* Allow passing maybe NULL raw_tp arguments to - * kfuncs for compatibility. Don't apply this to - * arguments with ref_obj_id > 0. - */ - mask = mask_raw_tp_reg(env, reg); if (!is_trusted_reg(reg)) { if (!is_kfunc_rcu(meta)) { verbose(env, "R%d must be referenced or trusted\n", regno); - unmask_raw_tp_reg(reg, mask); return -EINVAL; } if (!is_rcu_reg(reg)) { verbose(env, "R%d must be a rcu pointer\n", regno); - unmask_raw_tp_reg(reg, mask); return -EINVAL; } } - unmask_raw_tp_reg(reg, mask); fallthrough; case KF_ARG_PTR_TO_CTX: case KF_ARG_PTR_TO_DYNPTR: @@ -12348,9 +12315,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ if (is_kfunc_release(meta) && reg->ref_obj_id) arg_type |= OBJ_RELEASE; - mask = mask_raw_tp_reg(env, reg); ret = check_func_arg_reg_off(env, reg, regno, arg_type); - unmask_raw_tp_reg(reg, mask); if (ret < 0) return ret; @@ -12527,7 +12492,6 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ ref_tname = btf_name_by_offset(btf, ref_t->name_off); fallthrough; case KF_ARG_PTR_TO_BTF_ID: - mask = mask_raw_tp_reg(env, reg); /* Only base_type is checked, further checks are done here */ if ((base_type(reg->type) != PTR_TO_BTF_ID || (bpf_type_has_unsafe_modifiers(reg->type) && !is_rcu_reg(reg))) && @@ -12536,11 +12500,9 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ verbose(env, "expected %s or socket\n", reg_type_str(env, base_type(reg->type) | (type_flag(reg->type) & BPF_REG_TRUSTED_MODIFIERS))); - unmask_raw_tp_reg(reg, mask); return -EINVAL; } ret = process_kf_arg_ptr_to_btf_id(env, reg, ref_t, ref_tname, ref_id, meta, i); - unmask_raw_tp_reg(reg, mask); if (ret < 0) return ret; break; @@ -13513,7 +13475,7 @@ static int sanitize_check_bounds(struct bpf_verifier_env *env, */ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, struct bpf_insn *insn, - struct bpf_reg_state *ptr_reg, + const struct bpf_reg_state *ptr_reg, const struct bpf_reg_state *off_reg) { struct bpf_verifier_state *vstate = env->cur_state; @@ -13527,7 +13489,6 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, struct bpf_sanitize_info info = {}; u8 opcode = BPF_OP(insn->code); u32 dst = insn->dst_reg; - bool mask; int ret; dst_reg = ®s[dst]; @@ -13554,14 +13515,11 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, return -EACCES; } - mask = mask_raw_tp_reg(env, ptr_reg); if (ptr_reg->type & PTR_MAYBE_NULL) { verbose(env, "R%d pointer arithmetic on %s prohibited, null-check it first\n", dst, reg_type_str(env, ptr_reg->type)); - unmask_raw_tp_reg(ptr_reg, mask); return -EACCES; } - unmask_raw_tp_reg(ptr_reg, mask); switch (base_type(ptr_reg->type)) { case PTR_TO_CTX: @@ -16226,6 +16184,29 @@ enforce_retval: return 0; } +static void mark_subprog_changes_pkt_data(struct bpf_verifier_env *env, int off) +{ + struct bpf_subprog_info *subprog; + + subprog = find_containing_subprog(env, off); + subprog->changes_pkt_data = true; +} + +/* 't' is an index of a call-site. + * 'w' is a callee entry point. + * Eventually this function would be called when env->cfg.insn_state[w] == EXPLORED. + * Rely on DFS traversal order and absence of recursive calls to guarantee that + * callee's change_pkt_data marks would be correct at that moment. + */ +static void merge_callee_effects(struct bpf_verifier_env *env, int t, int w) +{ + struct bpf_subprog_info *caller, *callee; + + caller = find_containing_subprog(env, t); + callee = find_containing_subprog(env, w); + caller->changes_pkt_data |= callee->changes_pkt_data; +} + /* non-recursive DFS pseudo code * 1 procedure DFS-iterative(G,v): * 2 label v as discovered @@ -16359,6 +16340,7 @@ static int visit_func_call_insn(int t, struct bpf_insn *insns, bool visit_callee) { int ret, insn_sz; + int w; insn_sz = bpf_is_ldimm64(&insns[t]) ? 2 : 1; ret = push_insn(t, t + insn_sz, FALLTHROUGH, env); @@ -16370,8 +16352,10 @@ static int visit_func_call_insn(int t, struct bpf_insn *insns, mark_jmp_point(env, t + insn_sz); if (visit_callee) { + w = t + insns[t].imm + 1; mark_prune_point(env, t); - ret = push_insn(t, t + insns[t].imm + 1, BRANCH, env); + merge_callee_effects(env, t, w); + ret = push_insn(t, w, BRANCH, env); } return ret; } @@ -16688,6 +16672,8 @@ static int visit_insn(int t, struct bpf_verifier_env *env) mark_prune_point(env, t); mark_jmp_point(env, t); } + if (bpf_helper_call(insn) && bpf_helper_changes_pkt_data(insn->imm)) + mark_subprog_changes_pkt_data(env, t); if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) { struct bpf_kfunc_call_arg_meta meta; @@ -16822,6 +16808,7 @@ walk_cfg: } } ret = 0; /* cfg looks good */ + env->prog->aux->changes_pkt_data = env->subprog_info[0].changes_pkt_data; err_free: kvfree(insn_state); @@ -20075,7 +20062,6 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) * for this case. */ case PTR_TO_BTF_ID | MEM_ALLOC | PTR_UNTRUSTED: - case PTR_TO_BTF_ID | PTR_TRUSTED | PTR_MAYBE_NULL: if (type == BPF_READ) { if (BPF_MODE(insn->code) == BPF_MEM) insn->code = BPF_LDX | BPF_PROBE_MEM | @@ -20311,6 +20297,7 @@ static int jit_subprogs(struct bpf_verifier_env *env) func[i]->aux->num_exentries = num_exentries; func[i]->aux->tail_call_reachable = env->subprog_info[i].tail_call_reachable; func[i]->aux->exception_cb = env->subprog_info[i].is_exception_cb; + func[i]->aux->changes_pkt_data = env->subprog_info[i].changes_pkt_data; if (!i) func[i]->aux->exception_boundary = env->seen_exception; func[i] = bpf_int_jit_compile(func[i]); @@ -22141,6 +22128,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log, } if (tgt_prog) { struct bpf_prog_aux *aux = tgt_prog->aux; + bool tgt_changes_pkt_data; if (bpf_prog_is_dev_bound(prog->aux) && !bpf_prog_dev_bound_match(prog, tgt_prog)) { @@ -22175,6 +22163,14 @@ int bpf_check_attach_target(struct bpf_verifier_log *log, "Extension programs should be JITed\n"); return -EINVAL; } + tgt_changes_pkt_data = aux->func + ? aux->func[subprog]->aux->changes_pkt_data + : aux->changes_pkt_data; + if (prog->aux->changes_pkt_data && !tgt_changes_pkt_data) { + bpf_log(log, + "Extension program changes packet data, while original does not\n"); + return -EINVAL; + } } if (!tgt_prog->jited) { bpf_log(log, "Can attach to only JITed progs\n"); @@ -22640,10 +22636,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3 if (ret < 0) goto skip_full_check; - ret = check_attach_btf_id(env); - if (ret) - goto skip_full_check; - ret = resolve_pseudo_ldimm64(env); if (ret < 0) goto skip_full_check; @@ -22658,6 +22650,10 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr, __u3 if (ret < 0) goto skip_full_check; + ret = check_attach_btf_id(env); + if (ret) + goto skip_full_check; + ret = mark_fastcall_patterns(env); if (ret < 0) goto skip_full_check; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 949a3870946c..1b8db5aee9d3 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2250,6 +2250,9 @@ void perf_event_detach_bpf_prog(struct perf_event *event) goto unlock; old_array = bpf_event_rcu_dereference(event->tp_event->prog_array); + if (!old_array) + goto put; + ret = bpf_prog_array_copy(old_array, event->prog, NULL, 0, &new_array); if (ret < 0) { bpf_prog_array_delete_safe(old_array, event->prog); @@ -2258,6 +2261,14 @@ void perf_event_detach_bpf_prog(struct perf_event *event) bpf_prog_array_free_sleepable(old_array); } +put: + /* + * It could be that the bpf_prog is not sleepable (and will be freed + * via normal RCU), but is called from a point that supports sleepable + * programs and uses tasks-trace-RCU. + */ + synchronize_rcu_tasks_trace(); + bpf_prog_put(event->prog); event->prog = NULL; diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index fed382b7881b..4875e7f5de3d 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1402,9 +1402,13 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, #ifdef CONFIG_BPF_EVENTS if (bpf_prog_array_valid(call)) { + const struct bpf_prog_array *array; u32 ret; - ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run); + rcu_read_lock_trace(); + array = rcu_dereference_check(call->prog_array, rcu_read_lock_trace_held()); + ret = bpf_prog_run_array_uprobe(array, regs, bpf_prog_run); + rcu_read_unlock_trace(); if (!ret) return; } |