jerror.c: Silence MSan uninitialized value warning
If an error manager instance is passed to jpeg_std_error(), then its
format_message() method will point to the format_message() function in
jerror.c. The format_message() function passes all eight values from
the jpeg_error_mgr::msg_parm.i[] array as arguments to
snprintf()/_snprintf_s(), even if the format string doesn't use all of
those values. Subsequently invoking one of the ERREXIT[1-6]() macros
will leave the unused values uninitialized, and if the
-fsanitize-memory-param-retval option (introduced in Clang 14) is
enabled (which it is by default in Clang 16 and later), then MSan will
complain when the format_message() function tries to pass the
uninitialized-but-unused values as function arguments.
This commit modifies jpeg_std_error() so that it zeroes out the error
manager instance passed to it, thus working around the warning as well
as simplifying the code.
Closes #761
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a490a58..e8e3019 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -174,7 +174,7 @@
run: |
mkdir build
pushd build
- cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_C_COMPILER=clang -DCMAKE_C_FLAGS_RELWITHDEBINFO="-O0 -g -fsanitize=memory -fno-sanitize-recover=all -fPIE" -DWITH_SIMD=0 ..
+ cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_C_COMPILER=clang -DCMAKE_C_FLAGS_RELWITHDEBINFO="-O0 -g -fsanitize=memory -fsanitize-memory-param-retval -fno-sanitize-recover=all -fPIE" -DWITH_SIMD=0 ..
export NUMCPUS=`grep -c '^processor' /proc/cpuinfo`
make -j$NUMCPUS --load-average=$NUMCPUS
make test
diff --git a/jerror.c b/jerror.c
index c12c34f..3a75fec 100644
--- a/jerror.c
+++ b/jerror.c
@@ -229,23 +229,17 @@
GLOBAL(struct jpeg_error_mgr *)
jpeg_std_error(struct jpeg_error_mgr *err)
{
+ memset(err, 0, sizeof(struct jpeg_error_mgr));
+
err->error_exit = error_exit;
err->emit_message = emit_message;
err->output_message = output_message;
err->format_message = format_message;
err->reset_error_mgr = reset_error_mgr;
- err->trace_level = 0; /* default = no tracing */
- err->num_warnings = 0; /* no warnings emitted yet */
- err->msg_code = 0; /* may be useful as a flag for "no error" */
-
/* Initialize message table pointers */
err->jpeg_message_table = jpeg_std_message_table;
err->last_jpeg_message = (int)JMSG_LASTMSGCODE - 1;
- err->addon_message_table = NULL;
- err->first_addon_message = 0; /* for safety */
- err->last_addon_message = 0;
-
return err;
}
