https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104929
Bug ID: 104929 Summary: UBSAN: false positive with sprintf Product: gcc Version: 11.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: sanitizer Assignee: unassigned at gcc dot gnu.org Reporter: jengelh at inai dot de CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org, jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at gcc dot gnu.org Target Milestone: --- // g++ -Wall -fsanitize=undefined -O2 -c t.cpp #include <cstdio> size_t fun(char *s) { sprintf(s, " "); return __builtin_strlen(s); } Observed: t.cpp: In function ‘size_t fun(char*)’: t.cpp:5:16: warning: null destination pointer [-Wformat-overflow=] 5 | sprintf(s, " "); //gcc version 11.2.1 20220103 [revision d4a1d3c4b377f1d4acb34fe1b55b5088a3f293f6] (SUSE Linux), Linux amd64 glibc-2.35 Expected: Don't warn(?)