>From 5bff8967f45a35f858b96ca673d9bf98eac53d49 Mon Sep 17 00:00:00 2001 From: Serge E. Hallyn <[EMAIL PROTECTED]> Date: Wed, 31 Oct 2007 11:22:04 -0500 Subject: [PATCH 1/1] file capabilities: allow sigcont within session (v2)
(This is a proposed fix to http://bugzilla.kernel.org/show_bug.cgi?id=9247) Allow sigcont to be sent to a process with greater capabilities if it is in the same session. Otherwise, a shell from which I've started a root shell and done 'suspend' can't be restarted by the parent shell. Also don't do file-capabilities signaling checks when uids for the processes don't match, since the standard check_kill_permission will have done those checks. Signed-off-by: Serge E. Hallyn <[EMAIL PROTECTED]> --- security/commoncap.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index bf67871..4de6857 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -526,6 +526,15 @@ int cap_task_kill(struct task_struct *p, struct siginfo *info, if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) return 0; + /* if tasks have same uid, then check_kill_permission did check */ + if (current->uid == p->uid || current->euid == p->uid || + current->uid == p->suid || current->euid == p->suid) + return 0; + + /* sigcont is permitted within same session */ + if (sig == SIGCONT && (task_session_nr(current)==task_session_nr(p))) + return 0; + if (secid) /* * Signal sent as a particular user. -- 1.5.1.1.GIT - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
