From: Arnaldo Carvalho de Melo Date: Sat, 13 Jun 2026 18:25:11 +0000 (-0300) Subject: perf bpf: Validate array presence before casting BPF prog info pointers X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ebf4137d23a4fd6c0cc6a6fb766ee60d2b09193;p=thirdparty%2Flinux.git perf bpf: Validate array presence before casting BPF prog info pointers Several functions cast bpf_prog_info fields (jited_ksyms, jited_func_lens, jited_prog_insns) from u64 to pointers and dereference them. These fields are only valid pointers if bpil_offs_to_addr() converted their file offsets to addresses, which only happens when the corresponding PERF_BPIL_* bits are set in info_linear->arrays. A crafted perf.data can leave these bits unset while setting non-zero counts and offset values, causing the functions to dereference raw file offsets as pointers. Add array bitmask validation to all perf.data processing paths: - __bpf_event__print_bpf_prog_info(): check JITED_KSYMS and JITED_FUNC_LENS (changed to take struct perf_bpil *) - machine__process_bpf_event_load(): check JITED_KSYMS - bpf_read(): check JITED_INSNS before memcpy from jited_prog_insns - dso__disassemble_filename(): check JITED_INSNS before returning jited_prog_insns pointer Fixes: f8dfeae009effc0b ("perf bpf: Show more BPF program info in print_bpf_prog_info()") Reported-by: sashiko-bot Cc: Song Liu Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 57d53ba848359..fa3ebc8ea7f09 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -59,6 +59,10 @@ static int machine__process_bpf_event_load(struct machine *machine, return 0; info_linear = info_node->info_linear; + /* jited_ksyms is only valid if bpil_offs_to_addr() converted it */ + if (!(info_linear->arrays & (1UL << PERF_BPIL_JITED_KSYMS))) + return 0; + for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) { u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms); u64 addr = addrs[i]; @@ -959,12 +963,15 @@ int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); } -void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, +void __bpf_event__print_bpf_prog_info(struct perf_bpil *info_linear, struct perf_env *env, FILE *fp) { - __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); - __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); + struct bpf_prog_info *info = &info_linear->info; + __u64 required_arrays = (1UL << PERF_BPIL_JITED_KSYMS) | + (1UL << PERF_BPIL_JITED_FUNC_LENS); + __u32 *prog_lens; + __u64 *prog_addrs; char name[KSYM_NAME_LEN]; struct btf *btf = NULL; u32 sub_prog_cnt, i; @@ -974,6 +981,13 @@ void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, sub_prog_cnt != info->nr_jited_func_lens) return; + /* Ensure the arrays were present and converted by bpil_offs_to_addr() */ + if ((info_linear->arrays & required_arrays) != required_arrays) + return; + + prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); + prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); + if (info->btf_id) { struct btf_node *node; diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h index 60d2c6637af5d..da4eeb4a1a732 100644 --- a/tools/perf/util/bpf-event.h +++ b/tools/perf/util/bpf-event.h @@ -40,7 +40,7 @@ struct btf_node { int machine__process_bpf(struct machine *machine, union perf_event *event, struct perf_sample *sample); int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env); -void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, +void __bpf_event__print_bpf_prog_info(struct perf_bpil *info_linear, struct perf_env *env, FILE *fp); void bpf_metadata_free(struct bpf_metadata *metadata); @@ -58,7 +58,7 @@ static inline int evlist__add_bpf_sb_event(struct evlist *evlist __maybe_unused, return 0; } -static inline void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info __maybe_unused, +static inline void __bpf_event__print_bpf_prog_info(struct perf_bpil *info_linear __maybe_unused, struct perf_env *env __maybe_unused, FILE *fp __maybe_unused) { diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index 1a2fc6d18da74..79f1a30f3683d 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -880,6 +880,12 @@ static ssize_t bpf_read(struct dso *dso, u64 offset, char *data) return -1; } + /* jited_prog_insns is only valid if bpil_offs_to_addr() converted it */ + if (!(node->info_linear->arrays & (1UL << PERF_BPIL_JITED_INSNS))) { + dso__data(dso)->status = DSO_DATA_STATUS_ERROR; + return -1; + } + len = node->info_linear->info.jited_prog_len; buf = (u8 *)(uintptr_t)node->info_linear->info.jited_prog_insns; @@ -1995,6 +2001,10 @@ const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename, return NULL; } info_linear = info_node->info_linear; + if (!(info_linear->arrays & (1UL << PERF_BPIL_JITED_INSNS))) { + errno = SYMBOL_ANNOTATE_ERRNO__BPF_MISSING_BTF; + return NULL; + } assert(len <= info_linear->info.jited_prog_len); *out_buf_len = len; return (const u8 *)(uintptr_t)(info_linear->info.jited_prog_insns); diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index d7f41db7322cb..091d8f7f6bd2c 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2107,8 +2107,7 @@ static void print_bpf_prog_info(struct feat_fd *ff __maybe_unused, FILE *fp) node = rb_entry(next, struct bpf_prog_info_node, rb_node); next = rb_next(&node->rb_node); - __bpf_event__print_bpf_prog_info(&node->info_linear->info, - env, fp); + __bpf_event__print_bpf_prog_info(node->info_linear, env, fp); } up_read(&env->bpf_progs.lock);