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authorKees Cook <keescook@chromium.org>2022-02-13 10:24:43 -0800
committerArnaldo Carvalho de Melo <acme@redhat.com>2022-02-16 13:49:25 -0300
commit52a9dab6d892763b2a8334a568bd4e2c1a6fde66 (patch)
tree90599d721d407efdfb4e547ff07e784fc085a902 /tools
parent30d1c4d947983f3cfbff9cbb7a4d69b05b699678 (diff)
downloadlinux-52a9dab6d892763b2a8334a568bd4e2c1a6fde66.tar.bz2
libsubcmd: Fix use-after-free for realloc(..., 0)
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: 2f4ce5ec1d447beb ("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>
Diffstat (limited to 'tools')
-rw-r--r--tools/lib/subcmd/subcmd-util.h11
1 files changed, 2 insertions, 9 deletions
diff --git a/tools/lib/subcmd/subcmd-util.h b/tools/lib/subcmd/subcmd-util.h
index 794a375dad36..b2aec04fce8f 100644
--- a/tools/lib/subcmd/subcmd-util.h
+++ b/tools/lib/subcmd/subcmd-util.h
@@ -50,15 +50,8 @@ static NORETURN inline void die(const char *err, ...)
static inline void *xrealloc(void *ptr, size_t size)
{
void *ret = realloc(ptr, size);
- if (!ret && !size)
- ret = realloc(ptr, 1);
- if (!ret) {
- ret = realloc(ptr, size);
- if (!ret && !size)
- ret = realloc(ptr, 1);
- if (!ret)
- die("Out of memory, realloc failed");
- }
+ if (!ret)
+ die("Out of memory, realloc failed");
return ret;
}