Messages in this thread Patch in this message | | | Date | Tue, 2 Jan 2018 15:21:33 -0800 | From | Kees Cook <> | Subject | [PATCH] exec: Weaken dumpability for secureexec |
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This is a logical revert of:
commit e37fdb785a5f ("exec: Use secureexec for setting dumpability")
This weakens dumpability back to checking only for uid/gid changes in current (which is useless), but userspace depends on dumpability not being tied to secureexec.
https://bugzilla.redhat.com/show_bug.cgi?id=1528633
Reported-by: Tom Horsley <horsley1953@gmail.com> Fixes: e37fdb785a5f ("exec: Use secureexec for setting dumpability") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- fs/exec.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c index 5688b5e1b937..7eb8d21bcab9 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1349,9 +1349,14 @@ void setup_new_exec(struct linux_binprm * bprm) current->sas_ss_sp = current->sas_ss_size = 0; - /* Figure out dumpability. */ + /* + * Figure out dumpability. Note that this checking only of current + * is wrong, but userspace depends on it. This should be testing + * bprm->secureexec instead. + */ if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP || - bprm->secureexec) + !(uid_eq(current_euid(), current_uid()) && + gid_eq(current_egid(), current_gid()))) set_dumpable(current->mm, suid_dumpable); else set_dumpable(current->mm, SUID_DUMP_USER); -- 2.7.4
-- Kees Cook Pixel Security
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