Files
Linux/tools/lib
Kees Cook 52a9dab6d8 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: 2f4ce5ec1d ("perf tools: Finalize subcmd independence")
Reported-by: Valdis Klētnieks <[email protected]>
Signed-off-by: Kees Kook <[email protected]>
Tested-by: Valdis Klētnieks <[email protected]>
Tested-by: Justin M. Forbes <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Cc: [email protected]
Cc: Valdis Klētnieks <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-02-16 13:49:25 -03:00
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