Kees Cook 50f3b00d4c libsubcmd: Fix use-after-free for realloc(..., 0) ... commit 52a9dab6d892763b2a8334a568bd4e2c1a6fde66 upstream. GCC 12 correctly reports a potential use-after-free condition in the xrealloc helper. Fix the warning by avoiding an implicit "free(ptr)" when size == 0: In file included from help.c:12: In function 'xrealloc', inlined from 'add_cmdname' at help.c:24:2: subcmd-util.h:56:23: error: pointer may be used after 'realloc' [-Werror=use-after-free] 56 | ret = realloc(ptr, size); | ^~~~~~~~~~~~~~~~~~ subcmd-util.h:52:21: note: call to 'realloc' here 52 | void *ret = realloc(ptr, size); | ^~~~~~~~~~~~~~~~~~ subcmd-util.h:58:31: error: pointer may be used after 'realloc' [-Werror=use-after-free] 58 | ret = realloc(ptr, 1); | ^~~~~~~~~~~~~~~ subcmd-util.h:52:21: note: call to 'realloc' here 52 | void *ret = realloc(ptr, size); | ^~~~~~~~~~~~~~~~~~ Fixes: 2f4ce5ec1d ("perf tools: Finalize subcmd independence") Reported-by: Valdis Klētnieks <valdis.kletnieks@vt.edu> Signed-off-by: Kees Kook <keescook@chromium.org> Tested-by: Valdis Klētnieks <valdis.kletnieks@vt.edu> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: linux-hardening@vger.kernel.org Cc: Valdis Klētnieks <valdis.kletnieks@vt.edu> Link: http://lore.kernel.org/lkml/20220213182443.4037039-1-keescook@chromium.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2022-02-23 12:01:02 +01:00
..
Build
exec-cmd.c
exec-cmd.h
help.c
help.h
Makefile
pager.c
pager.h
parse-options.c
parse-options.h
run-command.c
run-command.h
sigchain.c
sigchain.h
subcmd-config.c
subcmd-config.h
subcmd-util.h