Ubuntu-focal-kernel/tools/lib
Kees Cook 7626e3c563 libsubcmd: Fix use-after-free for realloc(..., 0)
BugLink: https://bugs.launchpad.net/bugs/1967582

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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
2022-04-14 11:32:22 +02:00
..
api tools api fs: Make xxx__mountpoint() more scalable 2020-08-08 01:53:12 -04:00
bpf libbpf: Fix BTF data layout checks and allow empty BTF 2022-01-13 18:42:26 +01:00
lockdep
subcmd libsubcmd: Fix use-after-free for realloc(..., 0) 2022-04-14 11:32:22 +02:00
symbol
traceevent tools lib traceevent: Fix memory leak in process_dynamic_array_len 2020-09-04 16:28:45 -03:00
argv_split.c
bitmap.c
ctype.c
find_bit.c
hweight.c
rbtree.c rbtree: avoid generating code twice for the cached versions (tools copy) 2019-09-25 17:51:39 -07:00
str_error_r.c
string.c tools lib: Fix builds when glibc contains strlcpy() 2020-02-06 16:32:32 +00:00
vsprintf.c
zalloc.c