From 4effd088443b81b9c47147c56efbe6bfb867b131 Mon Sep 17 00:00:00 2001 From: Konstantin Andreev Date: Mon, 17 Jun 2024 01:44:30 +0300 Subject: [PATCH] smack: unix sockets: fix accept()ed socket label [ Upstream commit e86cac0acdb1a74f608bacefe702f2034133a047 ] When a process accept()s connection from a unix socket (either stream or seqpacket) it gets the socket with the label of the connecting process. For example, if a connecting process has a label 'foo', the accept()ed socket will also have 'in' and 'out' labels 'foo', regardless of the label of the listener process. This is because kernel creates unix child sockets in the context of the connecting process. I do not see any obvious way for the listener to abuse alien labels coming with the new socket, but, to be on the safe side, it's better fix new socket labels. Signed-off-by: Konstantin Andreev Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin --- security/smack/smack_lsm.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 75b3e91d5a5f..c18366dbbfed 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -3706,12 +3706,18 @@ static int smack_unix_stream_connect(struct sock *sock, } } - /* - * Cross reference the peer labels for SO_PEERSEC. - */ if (rc == 0) { + /* + * Cross reference the peer labels for SO_PEERSEC. + */ nsp->smk_packet = ssp->smk_out; ssp->smk_packet = osp->smk_out; + + /* + * new/child/established socket must inherit listening socket labels + */ + nsp->smk_out = osp->smk_out; + nsp->smk_in = osp->smk_in; } return rc;