From 7fa4b5b762c9a99b46b0b7838f5fd55071b92ea5 Mon Sep 17 00:00:00 2001 From: DRC Date: Mon, 6 May 2024 17:28:07 -0400 Subject: [PATCH] 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 --- .github/workflows/build.yml | 2 +- jerror.c | 10 ++-------- 2 files changed, 3 insertions(+), 9 deletions(-) diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml index a490a584..e8e30198 100644 --- a/.github/workflows/build.yml +++ b/.github/workflows/build.yml @@ -174,7 +174,7 @@ jobs: 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 c12c34fc..3a75fec0 100644 --- a/jerror.c +++ b/jerror.c @@ -229,23 +229,17 @@ reset_error_mgr(j_common_ptr cinfo) 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; }