lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 13 Jul 2017 17:42:45 +0200 From: Greg Kroah-Hartman <gregkh@...uxfoundation.org> To: linux-kernel@...r.kernel.org Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, stable@...r.kernel.org, GeneBlue <geneblue.mail@...il.com>, Cong Wang <xiyou.wangcong@...il.com>, Andrew Morton <akpm@...ux-foundation.org>, Manfred Spraul <manfred@...orfullife.com>, Linus Torvalds <torvalds@...ux-foundation.org> Subject: [PATCH 4.4 30/57] mqueue: fix a use-after-free in sys_mq_notify() 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cong Wang <xiyou.wangcong@...il.com> commit f991af3daabaecff34684fd51fac80319d1baad1 upstream. The retry logic for netlink_attachskb() inside sys_mq_notify() is nasty and vulnerable: 1) The sock refcnt is already released when retry is needed 2) The fd is controllable by user-space because we already release the file refcnt so we when retry but the fd has been just closed by user-space during this small window, we end up calling netlink_detachskb() on the error path which releases the sock again, later when the user-space closes this socket a use-after-free could be triggered. Setting 'sock' to NULL here should be sufficient to fix it. Reported-by: GeneBlue <geneblue.mail@...il.com> Signed-off-by: Cong Wang <xiyou.wangcong@...il.com> Cc: Andrew Morton <akpm@...ux-foundation.org> Cc: Manfred Spraul <manfred@...orfullife.com> Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org> --- ipc/mqueue.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -1251,8 +1251,10 @@ retry: timeo = MAX_SCHEDULE_TIMEOUT; ret = netlink_attachskb(sock, nc, &timeo, NULL); - if (ret == 1) + if (ret == 1) { + sock = NULL; goto retry; + } if (ret) { sock = NULL; nc = NULL;
Powered by blists - more mailing lists