Unfortunately, `g_memdup()` accepts its size argument as a `guint`,
unlike most other functions which deal with memory sizes — they all use
`gsize`. `gsize` is 64 bits on 64-bit machines, while `guint` is only 32
bits. This can lead to a silent (with default compiler warnings)
truncation of the value provided by the caller. For large values, this
will result in the returned heap allocation being significantly smaller
than the caller expects, which will then lead to buffer overflow
reads/writes.
Any code using `g_memdup()` should immediately port to `g_memdup2()` and
check the pointer arithmetic around their call site to ensure there
aren’t other overflows.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: #2319
The public API `GIOChannel.line_term_len` is only a `guint`. Ensure that
nul-terminated strings passed to `g_io_channel_set_line_term()` can’t
exceed that length. Use `g_memdup2()` to avoid a warning (`g_memdup()`
is due to be deprecated), but not to avoid a bug, since it’s also
limited to `G_MAXUINT`.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
The public API `g_tls_password_set_value_full()` (and the vfunc it
invokes) can only accept a `gssize` length. Ensure that nul-terminated
strings passed to `g_tls_password_set_value()` can’t exceed that length.
Use `g_memdup2()` to avoid an overflow if they’re longer than
`G_MAXUINT` similarly.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
Don’t use an `int`, that’s potentially too small. In practical terms,
this is not a problem, since no socket address is going to be that big.
By making these changes we can use `g_memdup2()` without warnings,
though. Fewer warnings is good.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
Previously, the code in `convert_path()` could not handle keys longer
than `G_MAXINT`, and would overflow if that was exceeded.
Convert the code to use `gsize` and `g_memdup2()` throughout, and
change from identifying the position of the final slash in the string
using a signed offset `i`, to using a pointer to the character (and
`strrchr()`). This allows the slash to be at any position in a
`G_MAXSIZE`-long string, without sacrificing a bit of the offset for
indicating whether a slash was found.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
This allows it to handle strings up to length `G_MAXSIZE` — previously
it would overflow with such strings.
Update the several copies of it identically.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
Previously it was handled as a `gssize`, which meant that if the
`stop_chars` string was longer than `G_MAXSSIZE` there would be an
overflow.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
The members of `URL_COMPONENTS` (`winhttp_file->url`) are `DWORD`s, i.e.
32-bit unsigned integers. Adding to and multiplying them may cause them
to overflow the unsigned integer bounds, even if the result is passed to
`g_memdup2()` which accepts a `gsize`.
Cast the `URL_COMPONENTS` members to `gsize` first to ensure that the
arithmetic is done in terms of `gsize`s rather than unsigned integers.
Spotted by Sebastian Dröge.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
Convert all the call sites which use `g_memdup()`’s length argument
trivially (for example, by passing a `sizeof()` or an existing `gsize`
variable), so that they use `g_memdup2()` instead.
In almost all of these cases the use of `g_memdup()` would not have
caused problems, but it will soon be deprecated, so best port away from
it
In particular, this fixes an overflow within `g_bytes_new()`, identified
as GHSL-2021-045 by GHSL team member Kevin Backhouse.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Fixes: GHSL-2021-045
Helps: #2319
Convert all the call sites which use `g_memdup()`’s length argument
trivially (for example, by passing a `sizeof()`), so that they use
`g_memdup2()` instead.
In almost all of these cases the use of `g_memdup()` would not have
caused problems, but it will soon be deprecated, so best port away from
it.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
Convert all the call sites which use `g_memdup()`’s length argument
trivially (for example, by passing a `sizeof()`), so that they use
`g_memdup2()` instead.
In almost all of these cases the use of `g_memdup()` would not have
caused problems, but it will soon be deprecated, so best port away from
it.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #2319
This will replace the existing `g_memdup()` function, which has an
unavoidable security flaw of taking its `byte_size` argument as a
`guint` rather than as a `gsize`. Most callers will expect it to be a
`gsize`, and may pass in large values which could silently be truncated,
resulting in an undersize allocation compared to what the caller
expects.
This could lead to a classic buffer overflow vulnerability for many
callers of `g_memdup()`.
`g_memdup2()`, in comparison, takes its `byte_size` as a `gsize`.
Spotted by Kevin Backhouse of GHSL.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: GHSL-2021-045
Helps: #2319
We're using "setuid" here as shorthand for any elevated privileges
that should make us distrust the caller: setuid, setgid, filesystem
capabilities, more obscure Linux things that set the AT_SECURE flag
(such as certain AppArmor transitions), and their equivalents on
other operating systems. This is fine if we do it consistently, but
I'm about to add a check for whether we are *literally* setuid,
which would be particularly confusing without a rename.
Signed-off-by: Simon McVittie <smcv@collabora.com>
gio/ghttpproxy.c: In function ‘g_http_proxy_connect’:
gio/ghttpproxy.c:245:17: error: comparison of integer expressions of different signedness: ‘gsize’ {aka ‘long unsigned int’} and ‘int’
245 | if (nread == -1)
| ^~
gio/ghttpproxy.c:253:22: error: comparison of integer expressions of different signedness: ‘gssize’ {aka ‘long int’} and ‘gsize’ {aka ‘long unsigned int’}
253 | if (bytes_read == buffer_length)
| ^~
Various tests have leaks where it isn't clear whether the data is
intentionally not freed, or leaked due to a bug. If we mark these
tests as TODO, we can skip them under AddressSanitizer and get the
rest to pass, giving us a baseline from which to avoid regressions.
Signed-off-by: Simon McVittie <smcv@collabora.com>
AddressSanitizer detects memory leaks, NULL parameters where only a
non-NULL parameter is expected, and other suspicious behaviour, so if
we try to test that sort of thing we can expect it to fail.
Signed-off-by: Simon McVittie <smcv@collabora.com>
AddressSanitizer, UndefinedBehaviourSanitizer and probably others
involve adding instrumentation into the code under test, which doesn't
go well with LD_PRELOAD modules that absolutely need to be
self-contained.
Signed-off-by: Simon McVittie <smcv@collabora.com>
gio/gapplication.c: In function ‘g_application_parse_command_line’:
gio/gapplication.c:545:11: error: missing initializer for field ‘arg_description’ of ‘GOptionEntry’ {aka ‘struct _GOptionEntry’}
545 | N_("Enter GApplication service mode (use from D-Bus service files)") },
| ^~
gio/gapplication.c:557:11: error: missing initializer for field ‘arg_description’ of ‘GOptionEntry’ {aka ‘struct _GOptionEntry’}
557 | N_("Override the application’s ID") },
| ^~
gio/gapplication.c:569:11: error: missing initializer for field ‘arg_description’ of ‘GOptionEntry’ {aka ‘struct _GOptionEntry’}
569 | N_("Replace the running instance") },
| ^~
gio/gdbusconnection.c: In function ‘g_dbus_connection_register_object_with_closures’:
gio/gdbusconnection.c:5527:5: error: missing initializer for field ‘padding’ of ‘GDBusInterfaceVTable’ {aka ‘struct _GDBusInterfaceVTable’}
5527 | };
| ^
gio/gdelayedsettingsbackend.c: In function ‘delayed_backend_path_writable_changed’:
gio/gdelayedsettingsbackend.c:406:7: error: missing initializer for field ‘index’ of ‘CheckPrefixState’
406 | CheckPrefixState state = { path, g_new (const gchar *, n_keys) };
| ^~~~~~~~~~~~~~~~
We have a "good" implementation of g_clear_signal_handler() in
form of a macro. Use it, and don't duplicate the code.
Also add a comment to the documentation that "instance" in fact must
not point to a valid GObject instance -- if the handler ID is unset.
Also reword the documentation about the reasoning for why a macro
version exists. The reason is not to use the function "without
pointer cast". I don't think the non-macro version requires any
pointer cast, since "instance" is a void pointer. Was this referring
to the handler_id_ptr? That doesn't seem right either, because the
caller should always provide a "gulong *" pointer and nothing else.
Preferably macros behave function-like to minimize surprises. That
means for example that they evaluate all arguments exactly once.
Rework g_clear_signal_handler() to assign the macro parameters
to auto variables so they are accessed exactly once.
Also, drop the static assert for the size of (*handler_id_ptr).
As we now assign to a "gulong *" pointer, the compiler already
checks the types. In fact, the check is now stricter than before.
Previously it would have allowed a pointer to a "signed long".
This is a change in behavior of the macro and the stricter compile
check could cause a build failure with broken code.
Also, clear the handler id first, before calling
g_signal_handler_disconnect(). Disconnecting a signal invokes the
destroy notify, which can have side effects. It just feels cleaner
to first reset the *_handler_id_ptr, before those side effects
can happen. Of course, in practice it makes little difference.
