• Kees Cook's avatar
    pstore/ram: Regularize prz label allocation lifetime · e163fdb3
    Kees Cook authored
    In my attempt to fix a memory leak, I introduced a double-free in the
    pstore error path. Instead of trying to manage the allocation lifetime
    between persistent_ram_new() and its callers, adjust the logic so
    persistent_ram_new() always takes a kstrdup() copy, and leaves the
    caller's allocation lifetime up to the caller. Therefore callers are
    _always_ responsible for freeing their label. Before, it only needed
    freeing when the prz itself failed to allocate, and not in any of the
    other prz failure cases, which callers would have no visibility into,
    which is the root design problem that lead to both the leak and now
    double-free bugs.
    Reported-by: default avatarCengiz Can <cengiz@kernel.wtf>
    Link: https://lore.kernel.org/lkml/d4ec59002ede4aaf9928c7f7526da87c@kernel.wtf
    Fixes: 8df955a3 ("pstore/ram: Fix error-path memory leak in persistent_ram_new() callers")
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarKees Cook <keescook@chromium.org>
    e163fdb3
ram.c 25.3 KB