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| author | Kees Cook <keescook@chromium.org> | 2022-02-13 10:24:43 -0800 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-02-16 13:49:25 -0300 |
| commit | 52a9dab6d892763b2a8334a568bd4e2c1a6fde66 (patch) | |
| tree | 90599d721d407efdfb4e547ff07e784fc085a902 /tools/lib | |
| parent | 30d1c4d947983f3cfbff9cbb7a4d69b05b699678 (diff) | |
| download | linux-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/lib')
| -rw-r--r-- | tools/lib/subcmd/subcmd-util.h | 11 |
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; } |