From patchwork Tue Jun 6 11:48:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Priour X-Patchwork-Id: 70645 X-Patchwork-Delegate: dmalcolm@redhat.com Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id BC9CE3831E30 for ; Tue, 6 Jun 2023 11:49:36 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BC9CE3831E30 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1686052176; bh=OzKmwWBDnoOTzN613g3XZ3xnGf1hwzHPUjDJLF5Sa4U=; h=To:Cc:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=vi51ZsG3Ivy+tACSzKeOdbJv/cbwIn5KO53LKHIYZ0ZEAgKsCfBzl1ZHXjsNNo0iD gNz82OOvFj6N5/rT1IXmqwIt7OyIPn/NhDY2zXMQXgNMKdlVyUTUY8iv7rDbMt7fAg YO/Ujw2hOoJdj1gco93VVkm3B+QhHNrUjXn8P6Lg= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) by sourceware.org (Postfix) with ESMTPS id 598953858C5F; Tue, 6 Jun 2023 11:49:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 598953858C5F Received: by mail-lf1-x12f.google.com with SMTP id 2adb3069b0e04-4f61d79b0f2so3882106e87.3; Tue, 06 Jun 2023 04:49:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686052146; x=1688644146; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=OzKmwWBDnoOTzN613g3XZ3xnGf1hwzHPUjDJLF5Sa4U=; b=ExQJflCzB1nyLT1kPr0SyKWEZXldKSYZs2A1t9fFXIItAy1MPuVDIJaYtrfqZcYcZt gXt+/JBgpxwzs7JE0PERL4jFU652jhgF49fQTFgDgQaz014MZmuxolzQvpKWMyNgYRyP Nr420BSOdGCCGP7jz0zIX22JtFyN13Qh29IJyXK6Y5qZGgQl7H6on1gxcAkpQ/N76jfp 5q0wDApFA7GvEVjg+7VkMJYxJJhzRpaF0ftKQT4zpV5wszopwa6mIxHqB32R9Jqo5bpm wn8xJOdo+215ySa9vnGVxtFCgzJVkZNpSWZ8wLd4g65CkqjOTjc//Amho2nmJsUYzchi PdGg== X-Gm-Message-State: AC+VfDxQCql2NSlbmOBbUTE4SAB1ZoWkEXP6k0jxe2h9B6Jlkv7Z//rv F1xWogTsLWNNex5p+x3Ye7cUJSwJ35Gezjo= X-Google-Smtp-Source: ACHHUZ5SOFcjAfegZtzRBcrPLM8X0w77qDmwdmJnKjVWW3jsQJ+Ps/wlIM/HkFW372laDxE/O0iCbQ== X-Received: by 2002:a2e:9253:0:b0:2b1:e965:e04f with SMTP id v19-20020a2e9253000000b002b1e965e04fmr969190ljg.26.1686052145419; Tue, 06 Jun 2023 04:49:05 -0700 (PDT) Received: from localhost ([2001:6b0:17:fc27:acef:d420:f755:376b]) by smtp.gmail.com with UTF8SMTPSA id n5-20020a2e86c5000000b002ac7a715585sm1835232ljj.30.2023.06.06.04.49.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 06 Jun 2023 04:49:04 -0700 (PDT) X-Google-Original-From: vultkayn@gcc.gnu.org To: gcc-patches@gcc.gnu.org Cc: Benjamin Priour , dmalcolm@redhat.com Subject: [PATCH] analyzer: Standalone OOB-warning [PR109437, PR109439] Date: Tue, 6 Jun 2023 13:48:58 +0200 Message-Id: <20230606114858.447221-1-vultkayn@gcc.gnu.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Benjamin Priour via Gcc-patches From: Benjamin Priour Reply-To: priour.be@gmail.com Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" From: Benjamin Priour This patch enchances -Wanalyzer-out-of-bounds that is no longer paired with a -Wanalyzer-use-of-uninitialized-value on out-of-bounds-read. This also fixes PR analyzer/109437. Before there could always be at most one OOB-read warning per frame because -Wanalyzer-use-of-uninitialized-value always terminates the analysis path. PR analyzer/109439 gcc/analyzer/ChangeLog: * bounds-checking.cc (region_model::check_symbolic_bounds): Returns whether the BASE_REG region access was OOB. (region_model::check_region_bounds): Likewise. * region-model.cc (region_model::get_store_value): Creates an unknown svalue on OOB-read access to REG. (region_model::check_region_access): Returns whether an unknown svalue needs be created. (region_model::check_region_for_read): Passes check_region_access return value. * region-model.h: Update prior function definitions. gcc/testsuite/ChangeLog: * gcc.dg/analyzer/out-of-bounds-2.c: Cleaned test for uninitialized-value warning. * gcc.dg/analyzer/out-of-bounds-5.c: Likewise. * gcc.dg/analyzer/pr101962.c: Likewise. * gcc.dg/analyzer/realloc-5.c: Likewise. * gcc.dg/analyzer/pr109439.c: New test. --- gcc/analyzer/bounds-checking.cc | 30 +++++++++++++------ gcc/analyzer/region-model.cc | 22 +++++++++----- gcc/analyzer/region-model.h | 8 ++--- .../gcc.dg/analyzer/out-of-bounds-2.c | 1 - .../gcc.dg/analyzer/out-of-bounds-5.c | 2 -- gcc/testsuite/gcc.dg/analyzer/pr101962.c | 1 - gcc/testsuite/gcc.dg/analyzer/pr109439.c | 12 ++++++++ gcc/testsuite/gcc.dg/analyzer/realloc-5.c | 1 - 8 files changed, 51 insertions(+), 26 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/analyzer/pr109439.c diff --git a/gcc/analyzer/bounds-checking.cc b/gcc/analyzer/bounds-checking.cc index 3bf542a8eba..479b8e4b88d 100644 --- a/gcc/analyzer/bounds-checking.cc +++ b/gcc/analyzer/bounds-checking.cc @@ -767,9 +767,11 @@ public: } }; -/* Check whether an access is past the end of the BASE_REG. */ +/* Check whether an access is past the end of the BASE_REG. + Return TRUE if the access was valid, FALSE otherwise. +*/ -void +bool region_model::check_symbolic_bounds (const region *base_reg, const svalue *sym_byte_offset, const svalue *num_bytes_sval, @@ -800,6 +802,7 @@ region_model::check_symbolic_bounds (const region *base_reg, offset_tree, num_bytes_tree, capacity_tree)); + return false; break; case DIR_WRITE: ctxt->warn (make_unique (base_reg, @@ -807,9 +810,11 @@ region_model::check_symbolic_bounds (const region *base_reg, offset_tree, num_bytes_tree, capacity_tree)); + return false; break; } } + return true; } static tree @@ -822,9 +827,11 @@ maybe_get_integer_cst_tree (const svalue *sval) return NULL_TREE; } -/* May complain when the access on REG is out-of-bounds. */ +/* May complain when the access on REG is out-of-bounds. + Return TRUE if the access was valid, FALSE otherwise. +*/ -void +bool region_model::check_region_bounds (const region *reg, enum access_direction dir, region_model_context *ctxt) const @@ -839,14 +846,14 @@ region_model::check_region_bounds (const region *reg, (e.g. because the analyzer did not see previous offsets on the latter, it might think that a negative access is before the buffer). */ if (base_reg->symbolic_p ()) - return; + return true; /* Find out how many bytes were accessed. */ const svalue *num_bytes_sval = reg->get_byte_size_sval (m_mgr); tree num_bytes_tree = maybe_get_integer_cst_tree (num_bytes_sval); /* Bail out if 0 bytes are accessed. */ if (num_bytes_tree && zerop (num_bytes_tree)) - return; + return true; /* Get the capacity of the buffer. */ const svalue *capacity = get_capacity (base_reg); @@ -877,13 +884,13 @@ region_model::check_region_bounds (const region *reg, } else byte_offset_sval = reg_offset.get_symbolic_byte_offset (); - check_symbolic_bounds (base_reg, byte_offset_sval, num_bytes_sval, + return check_symbolic_bounds (base_reg, byte_offset_sval, num_bytes_sval, capacity, dir, ctxt); - return; } /* Otherwise continue to check with concrete values. */ byte_range out (0, 0); + bool oob_safe = true; /* NUM_BYTES_TREE should always be interpreted as unsigned. */ byte_offset_t num_bytes_unsigned = wi::to_offset (num_bytes_tree); byte_range read_bytes (offset, num_bytes_unsigned); @@ -899,10 +906,12 @@ region_model::check_region_bounds (const region *reg, case DIR_READ: ctxt->warn (make_unique (reg, diag_arg, out)); + oob_safe = false; break; case DIR_WRITE: ctxt->warn (make_unique (reg, diag_arg, out)); + oob_safe = false; break; } } @@ -911,7 +920,7 @@ region_model::check_region_bounds (const region *reg, do a symbolic check here because the inequality check does not reason whether constants are greater than symbolic values. */ if (!cst_capacity_tree) - return; + return oob_safe; byte_range buffer (0, wi::to_offset (cst_capacity_tree)); /* If READ_BYTES exceeds BUFFER, we do have an overflow. */ @@ -929,13 +938,16 @@ region_model::check_region_bounds (const region *reg, case DIR_READ: ctxt->warn (make_unique (reg, diag_arg, out, byte_bound)); + oob_safe = false; break; case DIR_WRITE: ctxt->warn (make_unique (reg, diag_arg, out, byte_bound)); + oob_safe = false; break; } } + return oob_safe; } } // namespace ana diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc index 3bb3df2f063..fb96cd54940 100644 --- a/gcc/analyzer/region-model.cc +++ b/gcc/analyzer/region-model.cc @@ -2396,7 +2396,8 @@ region_model::get_store_value (const region *reg, if (reg->empty_p ()) return m_mgr->get_or_create_unknown_svalue (reg->get_type ()); - check_region_for_read (reg, ctxt); + if (check_region_for_read (reg, ctxt)) + return m_mgr->get_or_create_unknown_svalue(reg->get_type()); /* Special-case: handle var_decls in the constant pool. */ if (const decl_region *decl_reg = reg->dyn_cast_decl_region ()) @@ -2802,19 +2803,22 @@ region_model::get_string_size (const region *reg) const } /* If CTXT is non-NULL, use it to warn about any problems accessing REG, - using DIR to determine if this access is a read or write. */ + using DIR to determine if this access is a read or write. + Return TRUE if an UNKNOWN_SVALUE needs be created. */ -void +bool region_model::check_region_access (const region *reg, enum access_direction dir, region_model_context *ctxt) const { /* Fail gracefully if CTXT is NULL. */ if (!ctxt) - return; + return false; + bool need_unknown_sval = false; check_region_for_taint (reg, dir, ctxt); - check_region_bounds (reg, dir, ctxt); + if (!check_region_bounds (reg, dir, ctxt)) + need_unknown_sval = true; switch (dir) { @@ -2827,6 +2831,7 @@ region_model::check_region_access (const region *reg, check_for_writable_region (reg, ctxt); break; } + return need_unknown_sval; } /* If CTXT is non-NULL, use it to warn about any problems writing to REG. */ @@ -2838,13 +2843,14 @@ region_model::check_region_for_write (const region *dest_reg, check_region_access (dest_reg, DIR_WRITE, ctxt); } -/* If CTXT is non-NULL, use it to warn about any problems reading from REG. */ +/* If CTXT is non-NULL, use it to warn about any problems reading from REG. + Returns TRUE if an unknown svalue needs be created. */ -void +bool region_model::check_region_for_read (const region *src_reg, region_model_context *ctxt) const { - check_region_access (src_reg, DIR_READ, ctxt); + return check_region_access (src_reg, DIR_READ, ctxt); } /* Concrete subclass for casts of pointers that lead to trailing bytes. */ diff --git a/gcc/analyzer/region-model.h b/gcc/analyzer/region-model.h index fe3db0b0c98..12f84b20463 100644 --- a/gcc/analyzer/region-model.h +++ b/gcc/analyzer/region-model.h @@ -553,22 +553,22 @@ private: void check_for_writable_region (const region* dest_reg, region_model_context *ctxt) const; - void check_region_access (const region *reg, + bool check_region_access (const region *reg, enum access_direction dir, region_model_context *ctxt) const; - void check_region_for_read (const region *src_reg, + bool check_region_for_read (const region *src_reg, region_model_context *ctxt) const; void check_region_size (const region *lhs_reg, const svalue *rhs_sval, region_model_context *ctxt) const; /* Implemented in bounds-checking.cc */ - void check_symbolic_bounds (const region *base_reg, + bool check_symbolic_bounds (const region *base_reg, const svalue *sym_byte_offset, const svalue *num_bytes_sval, const svalue *capacity, enum access_direction dir, region_model_context *ctxt) const; - void check_region_bounds (const region *reg, enum access_direction dir, + bool check_region_bounds (const region *reg, enum access_direction dir, region_model_context *ctxt) const; void check_call_args (const call_details &cd) const; diff --git a/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-2.c b/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-2.c index 1330090f348..336f624441c 100644 --- a/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-2.c +++ b/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-2.c @@ -82,5 +82,4 @@ void test5 (void) /* { dg-warning "heap-based buffer over-read" "bounds warning" { target *-*-* } test5 } */ /* { dg-message "read of 4 bytes from after the end of the region" "num bad bytes note" { target *-*-* } test5 } */ - /* { dg-warning "use of uninitialized value" "uninit warning" { target *-*-* } test5 } */ } diff --git a/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-5.c b/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-5.c index 2a61d8ca236..568f9cad199 100644 --- a/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-5.c +++ b/gcc/testsuite/gcc.dg/analyzer/out-of-bounds-5.c @@ -68,7 +68,6 @@ void test8 (size_t size, size_t offset) char dst[size]; memcpy (dst, src, size + offset); /* { dg-line test8 } */ /* { dg-warning "over-read" "warning" { target *-*-* } test8 } */ - /* { dg-warning "use of uninitialized value" "warning" { target *-*-* } test8 } */ /* { dg-warning "overflow" "warning" { target *-*-* } test8 } */ } @@ -78,7 +77,6 @@ void test9 (size_t size, size_t offset) int32_t dst[size]; memcpy (dst, src, 4 * size + 1); /* { dg-line test9 } */ /* { dg-warning "over-read" "warning" { target *-*-* } test9 } */ - /* { dg-warning "use of uninitialized value" "warning" { target *-*-* } test9 } */ /* { dg-warning "overflow" "warning" { target *-*-* } test9 } */ } diff --git a/gcc/testsuite/gcc.dg/analyzer/pr101962.c b/gcc/testsuite/gcc.dg/analyzer/pr101962.c index 08c0aba5cbf..b878aad9cf1 100644 --- a/gcc/testsuite/gcc.dg/analyzer/pr101962.c +++ b/gcc/testsuite/gcc.dg/analyzer/pr101962.c @@ -24,7 +24,6 @@ test_1 (void) __analyzer_eval (a != NULL); /* { dg-warning "TRUE" } */ return *a; /* { dg-line test_1 } */ - /* { dg-warning "use of uninitialized value '\\*a'" "warning" { target *-*-* } test_1 } */ /* { dg-warning "stack-based buffer over-read" "warning" { target *-*-* } test_1 } */ } diff --git a/gcc/testsuite/gcc.dg/analyzer/pr109439.c b/gcc/testsuite/gcc.dg/analyzer/pr109439.c new file mode 100644 index 00000000000..01c87cf171c --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/pr109439.c @@ -0,0 +1,12 @@ +int would_like_only_oob (int i) +{ + int arr[] = {1,2,3,4,5,6,7}; + arr[10] = 9; /* { dg-warning "stack-based buffer overflow" } */ + arr[11] = 15; /* { dg-warning "stack-based buffer overflow" } */ + int y1 = arr[9]; /* { dg-warning "stack-based buffer over-read" } */ + /* { dg-bogus "use of uninitialized value" "" { target *-*-* } .-1 } */ + + arr[18] = 15; /* { dg-warning "stack-based buffer overflow" } */ + + return y1; +} diff --git a/gcc/testsuite/gcc.dg/analyzer/realloc-5.c b/gcc/testsuite/gcc.dg/analyzer/realloc-5.c index 137e05b87aa..f65f2c6ca25 100644 --- a/gcc/testsuite/gcc.dg/analyzer/realloc-5.c +++ b/gcc/testsuite/gcc.dg/analyzer/realloc-5.c @@ -40,7 +40,6 @@ void test_1 () /* { dg-warning "UNKNOWN" "warning" { target *-*-* } eval } */ /* { dg-warning "heap-based buffer over-read" "warning" { target *-*-* } eval } */ - /* { dg-warning "use of uninitialized value" "warning" { target *-*-* } eval } */ } free (q);