From 91ad997a34d7abca1f04e819e31eb9f3d4e20585 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Wed, 14 Nov 2007 17:00:34 -0800 Subject: [PATCH] file capabilities: allow sigcont within session Fix 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. [akpm@linux-foundation.org: coding-style cleanups] Signed-off-by: Serge E. Hallyn Acked-by: Andrew Morgan Cc: Chris Wright Tested-by: "Theodore Ts'o" Cc: Stephen Smalley Cc: "Rafael J. Wysocki" Cc: Chris Wright Cc: James Morris Cc: Stephen Smalley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/commoncap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/security/commoncap.c b/security/commoncap.c index bf67871173ef..302e8d0839a9 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -526,6 +526,10 @@ 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; + /* 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. -- 2.20.1