https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64187
Bug ID: 64187 Summary: Writing to a char array cast from a char * causes a segmentation fault Product: gcc Version: 4.3.4 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: brian.corriveau at ericsson dot com Created attachment 34193 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34193&action=edit sample that produces segmentation fault I was trying to work around a coverity optional data[0] overrun issue when I came across this problem. The code casts a char * to a char (*)[200], and tries to write to it. This causes a segmentation fault. System: :~/src[1050]uname -a Linux eussjlxxen204 2.6.32.45-0.3-xen #1 SMP 2011-08-22 10:12:58 +0200 x86_64 x86_64 x86_64 GNU/Linux Here is the compiler output: gcc -v -save-temps -g array.c Using built-in specs. Target: x86_64-suse-linux Configured with: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64 --enable-languages=c,c++,objc,fortran,obj-c++,java,ada --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.3 --enable-ssp --disable-libssp --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --disable-libgcj --disable-libmudflap --with-slibdir=/lib64 --with-system-zlib --enable-__cxa_atexit --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-version-specific-runtime-libs --program-suffix=-4.3 --enable-linux-futex --without-system-libunwind --with-cpu=generic --build=x86_64-suse-linux Thread model: posix gcc version 4.3.4 [gcc-4_3-branch revision 152973] (SUSE Linux) COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-mtune=generic' /usr/lib64/gcc/x86_64-suse-linux/4.3/cc1 -E -quiet -v array.c -mtune=generic -fworking-directory -fpch-preprocess -o array.i #include "..." search starts here: #include <...> search starts here: /usr/local/include /usr/lib64/gcc/x86_64-suse-linux/4.3/include /usr/lib64/gcc/x86_64-suse-linux/4.3/include-fixed /usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/include /usr/include End of search list. COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-mtune=generic' /usr/lib64/gcc/x86_64-suse-linux/4.3/cc1 -fpreprocessed array.i -quiet -dumpbase array.c -mtune=generic -auxbase array -g -version -o array.s GNU C (SUSE Linux) version 4.3.4 [gcc-4_3-branch revision 152973] (x86_64-suse-linux) compiled by GNU C version 4.3.4 [gcc-4_3-branch revision 152973], GMP version 4.2.3, MPFR version 2.3.2. GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 91a878d77972b76d647d592fefc786fc COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-mtune=generic' /usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/as -V -Qy -o array.o array.s GNU assembler version 2.20.0 (x86_64-suse-linux) using BFD version (GNU Binutils; SUSE Linux Enterprise 11) 2.20.0.20100122-0.7.9 COMPILER_PATH=/usr/lib64/gcc/x86_64-suse-linux/4.3/:/usr/lib64/gcc/x86_64-suse-linux/4.3/:/usr/lib64/gcc/x86_64-suse-linux/:/usr/lib64/gcc/x86_64-suse-linux/4.3/:/usr/lib64/gcc/x86_64-suse-linux/:/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/ LIBRARY_PATH=/usr/lib64/gcc/x86_64-suse-linux/4.3/:/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/lib/:/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-mtune=generic' /usr/lib64/gcc/x86_64-suse-linux/4.3/collect2 --build-id --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../lib64/crt1.o /usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../lib64/crti.o /usr/lib64/gcc/x86_64-suse-linux/4.3/crtbegin.o -L/usr/lib64/gcc/x86_64-suse-linux/4.3 -L/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/lib -L/usr/lib64/gcc/x86_64-suse-linux/4.3/../../.. array.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib64/gcc/x86_64-suse-linux/4.3/crtend.o /usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../lib64/crtn.o Run output: :~/src[1047]./a.out hEllo Segmentation fault