From 8c983a7ebd562f9e45a2b8ca623167b179bfd98f Mon Sep 17 00:00:00 2001 From: Mark Andrews Date: Tue, 18 Feb 2020 09:40:21 +1100 Subject: [PATCH] Simplify hash computation to prevent pointer being classed as tainted. mem.c:add_trace_entry() -> isc_hash_function() -> isc_siphash24() 129 for (; in != end; in += 8) { 6. byte_swapping: Performing a byte swapping operation on in implies that it came from an external source, and is therefore tainted. 130 uint64_t m = U8TO64_LE(in); --- lib/isc/mem.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/lib/isc/mem.c b/lib/isc/mem.c index 9a339b06c9..5e4b3d1004 100644 --- a/lib/isc/mem.c +++ b/lib/isc/mem.c @@ -272,7 +272,15 @@ add_trace_entry(isc__mem_t *mctx, const void *ptr, size_t size FLARG) { return; } +#ifdef __COVERITY__ + /* + * Use simple conversion from pointer to hash to avoid + * tainting 'ptr' due to byte swap in isc_hash_function. + */ + hash = (uintptr_t)ptr >> 3; +#else hash = isc_hash_function(&ptr, sizeof(ptr), true); +#endif idx = hash % DEBUG_TABLE_COUNT; dl = malloc(sizeof(debuglink_t)); @@ -308,7 +316,15 @@ delete_trace_entry(isc__mem_t *mctx, const void *ptr, size_t size, return; } +#ifdef __COVERITY__ + /* + * Use simple conversion from pointer to hash to avoid + * tainting 'ptr' due to byte swap in isc_hash_function. + */ + hash = (uintptr_t)ptr >> 3; +#else hash = isc_hash_function(&ptr, sizeof(ptr), true); +#endif idx = hash % DEBUG_TABLE_COUNT; dl = ISC_LIST_HEAD(mctx->debuglist[idx]);