diff options
| author | Kees Cook <keescook@chromium.org> | 2017-07-19 01:25:31 +0300 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2017-08-01 22:03:10 +0300 |
| commit | e37fdb785a5f95ecadf43b773c97f676500ac7b8 (patch) | |
| tree | da2a0c619be4777fbfb33caf5078a9453782fd9d /fs | |
| parent | 2af622802696e1dbe28d81c8ea6355dc30800396 (diff) | |
| download | linux-e37fdb785a5f95ecadf43b773c97f676500ac7b8.tar.xz | |
exec: Use secureexec for setting dumpability
The examination of "current" to decide dumpability is wrong. This was a
check of and euid/uid (or egid/gid) mismatch in the existing process,
not the newly created one. This appears to stretch back into even the
"history.git" tree. Luckily, dumpability is later set in commit_creds().
In earlier kernel versions before creds existed, similar checks also
existed late in the exec flow, covering up the mistake as far back as I
could find.
Note that because the commit_creds() check examines differences of euid,
uid, egid, gid, and capabilities between the old and new creds, it would
look like the setup_new_exec() dumpability test could be entirely removed.
However, the secureexec test may cover a different set of tests (specific
to the LSMs) than what commit_creds() checks for. So, fix this test to
use secureexec (the removed euid tests are redundant to the commoncap
secureexec checks now).
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exec.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c index eca0cb550a06..3536437ffd76 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1354,7 +1354,7 @@ void setup_new_exec(struct linux_binprm * bprm) current->sas_ss_sp = current->sas_ss_size = 0; - if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid())) + if (!bprm->secureexec) set_dumpable(current->mm, SUID_DUMP_USER); else set_dumpable(current->mm, suid_dumpable); |