-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ryan Mallon wrote: >> ... > That's fine. I originally went looking after a discussion with > Mark about the weird strnlen_user semantics and this usage looked > incorrect to me because it wasn't obviously checking >= > MAX_ARG_STRLEN. > > The rework I think makes it a bit more clear and passes the correct > max length to strnlen_user. Its a bit odd to pass MAX_ARG_STRLEN > and then check if it is longer than bprm->len, and I guess assumes > that bprm->len is less than MAX_ARG_STRLEN. > > Feel free to drop the patch if you think it is just churn. As you are already busy with fs/exec.c and strnlen_user, could you please check, if the timerace (argv/envp corruption) using strnlen_user could also be fixed within the same patch (if bug still in kernel). See https://bugzilla.kernel.org/show_bug.cgi?id=39222 The race occurs when one thread issues exec while another one with shared memory pages is flipping char/0-bytes of the args or envptrs, causing random split (number greater maxargs - no problem, silently droped)/fusion (greater MAX_ARG_STRLEN - might harm dumb programs) or removal of all args including program name on top of new stack when calling via binfmt handlers (might have influenced old ldlinux/libc pre 2009?? when handling suid binaries) Kind Regards, Roman - -- http://www.halfdog.net/ PGP: 156A AE98 B91F 0114 FE88 2BD8 C459 9386 feed a bee -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFOc3tJxFmThv7tq+4RAibwAJ9CmDTlODxFuNR4KrSh9PGjgyXxQwCfeIgo ARy24fJ6DxuKmcPNla6f0lE= =h1TA -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
