There is an issue where calls to bzero (memset(), etc) can be eliminated due to an optimizing compiler eliminating the call to bzero() (or memset(), etc) because the arguments to the call are not subsequently used by the function. The compiler can interpret this as "no side effects", and eliminate the call.
The origin source of issue to being brought to light with a security focus' is here: http://cwe.mitre.org/data/definitions/14.html The issue was discovered in DPDK while looking at PVS Studio blog about bugs: https://pvs-studio.com/en/blog/posts/cpp/1183/ In DPDK there are three types of anti-patterns: 1. trying to clear a key or sensitive data but using memset 2. being overly paranoid and always calling memset 3. unnecessary arrays (cut and paste?) that are memset v9 - drop the standalone test for explicit zero because testing that code is not optimized away requires some non-portable hacks using altstack and/or glibc setcontext hooks. Not worth the hassle doing this and maintaining, just trust that libc works as expected. Stephen Hemminger (15): eal: introduce new secure memory zero app/test: remove unused variable eal: add new secure free function app/test: use unit test runner for malloc tests app/test: add test for rte_free_sensitive common/cnxk: remove unused variable crypto/qat: force zero of keys crypto/qat: fix size calculation for memset crypto/qat: use secure free for keys bus/uacce: remove memset before free compress/octeontx: remove unnecessary memset test: remove unneeded memset net/ntnic: check result of malloc net/ntnic: remove unnecessary memset devtools/cocci: add script to find problematic memset app/test/test_cmdline_cirbuf.c | 4 - app/test/test_malloc.c | 194 ++++++++++-------- devtools/cocci/memset_free.cocci | 9 + drivers/bus/uacce/uacce.c | 1 - drivers/common/cnxk/roc_npc_utils.c | 4 - drivers/compress/octeontx/otx_zip.c | 1 - drivers/compress/octeontx/otx_zip_pmd.c | 2 - drivers/crypto/qat/qat_asym.c | 5 +- drivers/crypto/qat/qat_sym_session.c | 51 ++--- drivers/net/ntnic/nthw/core/nthw_hif.c | 5 +- drivers/net/ntnic/nthw/core/nthw_iic.c | 5 +- drivers/net/ntnic/nthw/core/nthw_pcie3.c | 5 +- drivers/net/ntnic/nthw/core/nthw_rpf.c | 5 +- drivers/net/ntnic/nthw/core/nthw_sdc.c | 5 +- drivers/net/ntnic/nthw/core/nthw_si5340.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_cat.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_csu.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_flm.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_hfu.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_hsh.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_info.c | 5 +- .../net/ntnic/nthw/flow_filter/flow_nthw_km.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_pdb.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_qsl.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_rpp_lr.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_slc_lr.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_tx_cpy.c | 1 - .../ntnic/nthw/flow_filter/flow_nthw_tx_ins.c | 5 +- .../ntnic/nthw/flow_filter/flow_nthw_tx_rpl.c | 5 +- .../net/ntnic/nthw/model/nthw_fpga_model.c | 1 - drivers/net/ntnic/nthw/nthw_rac.c | 4 +- lib/eal/common/eal_common_string_fns.c | 14 ++ lib/eal/common/rte_malloc.c | 30 ++- lib/eal/include/rte_malloc.h | 23 +++ lib/eal/include/rte_string_fns.h | 18 ++ lib/eal/version.map | 4 + 36 files changed, 251 insertions(+), 210 deletions(-) create mode 100644 devtools/cocci/memset_free.cocci -- 2.47.2
