From: Kirill Radkin <kirill.radkin@syntacore.com>
To: <gdb-patches@sourceware.org>
Cc: Kirill Radkin <kirill.radkin@syntacore.com>
Subject: [PATCH v2] gdbserver: Fix overflow detection in gdbserver
Date: Mon, 19 Feb 2024 17:19:55 +0300 [thread overview]
Message-ID: <20240219141955.34929-1-kirill.radkin@syntacore.com> (raw)
In-Reply-To: <87plx79bdm.fsf@tromey.com>
> I don't understand this early return.
> If using an unsigned type here is intended to be invalid, then I think
> that should be enforced at compile time.
Early return removed.
> However, it seems pretty simple to handle unsigned here as well.
Added.
Currently gdbserver uses require_int() function to
parse the requested offset (in vFile::pread
packet and the like). This function allows integers up to 0x7fffffff
(to fit in 32-bit int), however the offset (for pread
system call) has an off_t type which can be larger than
32-bit.
This patch allows require_int() function to parse offset
up to the maximum value implied by the off_t type.
---
gdb/testsuite/gdb.server/pread-offset-size.S | 23 +++++++++
.../gdb.server/pread-offset-size.exp | 50 +++++++++++++++++++
gdbserver/hostio.cc | 17 +++++--
3 files changed, 86 insertions(+), 4 deletions(-)
create mode 100644 gdb/testsuite/gdb.server/pread-offset-size.S
create mode 100644 gdb/testsuite/gdb.server/pread-offset-size.exp
diff --git a/gdb/testsuite/gdb.server/pread-offset-size.S b/gdb/testsuite/gdb.server/pread-offset-size.S
new file mode 100644
index 00000000000..b07058e5550
--- /dev/null
+++ b/gdb/testsuite/gdb.server/pread-offset-size.S
@@ -0,0 +1,23 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2023 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+ .text
+ .globl _start
+_start:
+ .skip 3742415472
+ .globl f
+f:
diff --git a/gdb/testsuite/gdb.server/pread-offset-size.exp b/gdb/testsuite/gdb.server/pread-offset-size.exp
new file mode 100644
index 00000000000..221491bfa04
--- /dev/null
+++ b/gdb/testsuite/gdb.server/pread-offset-size.exp
@@ -0,0 +1,50 @@
+# Copyright (C) 2023 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# Test sending of large binary files (>2 GB) from gdbserver
+# (it was unavailable earlier)
+
+load_lib gdbserver-support.exp
+
+if {![allow_gdbserver_tests]} {
+ return
+}
+
+standard_testfile .S
+
+if { [prepare_for_testing ${testfile}.exp $testfile \
+ $srcfile {debug additional_flags=-nostdlib} ] } {
+ return -1
+}
+
+gdb_exit
+gdb_start
+
+gdb_test_no_output "set remote exec-file $binfile" \
+"set remote exec-file"
+
+# Make sure we're disconnected, in case we're testing with an
+# extended-remote board, therefore already connected.
+gdb_test "disconnect" ".*"
+
+set res [gdbserver_spawn ""]
+set gdbserver_protocol [lindex $res 0]
+set gdbserver_gdbport [lindex $res 1]
+
+gdb_test "target $gdbserver_protocol $gdbserver_gdbport" \
+"Remote debugging using .*" \
+"target $gdbserver_protocol $gdbserver_gdbport"
+
+gdb_test "break f" "Breakpoint 1.*"
diff --git a/gdbserver/hostio.cc b/gdbserver/hostio.cc
index ea70c26da0f..fcee553c5a3 100644
--- a/gdbserver/hostio.cc
+++ b/gdbserver/hostio.cc
@@ -90,12 +90,18 @@ require_filename (char **pp, char *filename)
return 0;
}
+template <typename T>
static int
-require_int (char **pp, int *value)
+require_int (char **pp, T *value)
{
+ constexpr bool is_signed = std::is_signed<T>::value;
+
char *p;
int count, firstdigit;
+ /* Max count of hexadecimal digits in off_t (1 hex digit is 4 bits) */
+ int max_count = sizeof(T) * CHAR_BIT / 4;
+
p = *pp;
*value = 0;
count = 0;
@@ -112,7 +118,8 @@ require_int (char **pp, int *value)
firstdigit = nib;
/* Don't allow overflow. */
- if (count >= 8 || (count == 7 && firstdigit >= 0x8))
+ if (count >= max_count || (is_signed && count == (max_count - 1)
+ && firstdigit >= 0x8))
return -1;
*value = *value * 16 + nib;
@@ -344,7 +351,8 @@ handle_open (char *own_buf)
static void
handle_pread (char *own_buf, int *new_packet_len)
{
- int fd, ret, len, offset, bytes_sent;
+ int fd, ret, len, bytes_sent;
+ off_t offset;
char *p, *data;
static int max_reply_size = -1;
@@ -411,7 +419,8 @@ handle_pread (char *own_buf, int *new_packet_len)
static void
handle_pwrite (char *own_buf, int packet_len)
{
- int fd, ret, len, offset;
+ int fd, ret, len;
+ off_t offset;
char *p, *data;
p = own_buf + strlen ("vFile:pwrite:");
--
2.34.1
prev parent reply other threads:[~2024-02-19 14:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 8:38 [PATCH] [gdbserver] " Kirill Radkin
2023-12-21 19:42 ` Simon Marchi
2023-12-22 15:41 ` Tom Tromey
2024-01-10 14:57 ` [PATCH] gdbserver: " Kirill Radkin
2024-02-08 16:19 ` Tom Tromey
2024-02-19 14:19 ` Kirill Radkin [this message]
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