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From 44d6b1169915913fae640dada5ed931dffff6772 Mon Sep 17 00:00:00 2001
From: "C. Erastus Toe" <ctoe@redhat.com>
Date: Fri, 18 Feb 2022 01:09:25 -0500
Subject: [KPATCH CVE-2021-4028] kpatch fixes for CVE-2021-4028

Kernels:
3.10.0-1160.21.1.el7
3.10.0-1160.24.1.el7
3.10.0-1160.25.1.el7
3.10.0-1160.31.1.el7
3.10.0-1160.36.2.el7
3.10.0-1160.41.1.el7
3.10.0-1160.42.2.el7
3.10.0-1160.45.1.el7
3.10.0-1160.49.1.el7
3.10.0-1160.53.1.el7

Changes since last build:
arches: x86_64 ppc64le
cma.o: changed function: rdma_listen
---------------------------

Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-7/-/merge_requests/25
Approved-by: Joe Lawrence (@joe.lawrence)
Modifications: none

commit 00225da7d36440d257a98004ee2e7f288486245b
Author: Kamal Heib <kheib@redhat.com>
Date:   Sun Jan 16 11:38:26 2022 +0200

    RDMA/cma: Do not change route.addr.src_addr.ss_family

    Bugzilla: http://bugzilla.redhat.com/2032075
    CVE: CVE-2021-4028
    Conflicts:
    The conditional statement to verify RDMA_CM_IDLE state is a
    little bit different from the upstream to 7.9.z source. The commit
    732d41c545bb (RDMA/cma: Make the locking for automatic state transition
    more clear) is missing from 7.9.z. So, the context has been modified.

    commit bc0bdc5afaa740d782fbf936aaeebd65e5c2921d
    Author: Jason Gunthorpe <jgg@nvidia.com>
    Date:   Wed Sep 15 17:21:43 2021 -0300

        RDMA/cma: Do not change route.addr.src_addr.ss_family

        If the state is not idle then rdma_bind_addr() will immediately fail and
        no change to global state should happen.

        For instance if the state is already RDMA_CM_LISTEN then this will corrupt
        the src_addr and would cause the test in cma_cancel_operation():

                        if (cma_any_addr(cma_src_addr(id_priv)) && !id_priv->cma_dev)

        To view a mangled src_addr, eg with a IPv6 loopback address but an IPv4
        family, failing the test.

        This would manifest as this trace from syzkaller:

          BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26
          Read of size 8 at addr ffff8881546491e0 by task syz-executor.1/32204

          CPU: 1 PID: 32204 Comm: syz-executor.1 Not tainted 5.12.0-rc8-syzkaller #0
          Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
          Call Trace:
           __dump_stack lib/dump_stack.c:79 [inline]
           dump_stack+0x141/0x1d7 lib/dump_stack.c:120
           print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232
           __kasan_report mm/kasan/report.c:399 [inline]
           kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416
           __list_add_valid+0x93/0xa0 lib/list_debug.c:26
           __list_add include/linux/list.h:67 [inline]
           list_add_tail include/linux/list.h:100 [inline]
           cma_listen_on_all drivers/infiniband/core/cma.c:2557 [inline]
           rdma_listen+0x787/0xe00 drivers/infiniband/core/cma.c:3751
           ucma_listen+0x16a/0x210 drivers/infiniband/core/ucma.c:1102
           ucma_write+0x259/0x350 drivers/infiniband/core/ucma.c:1732
           vfs_write+0x28e/0xa30 fs/read_write.c:603
           ksys_write+0x1ee/0x250 fs/read_write.c:658
           do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
           entry_SYSCALL_64_after_hwframe+0x44/0xae

        Which is indicating that an rdma_id_private was destroyed without doing
        cma_cancel_listens().

        Instead of trying to re-use the src_addr memory to indirectly create an
        any address build one explicitly on the stack and bind to that as any
        other normal flow would do.

        Link: https://lore.kernel.org/r/0-v1-9fbb33f5e201+2a-cma_listen_jgg@nvidia.com
        Cc: stable@vger.kernel.org
        Fixes: 732d41c545bb ("RDMA/cma: Make the locking for automatic state transition more clear")
        Reported-by: syzbot+6bb0528b13611047209c@syzkaller.appspotmail.com
        Tested-by: Hao Sun <sunhao.th@gmail.com>
        Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
        Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

    Signed-off-by: Kamal Heib <kheib@redhat.com>

Signed-off-by: C. Erastus Toe <ctoe@redhat.com>
---
 drivers/infiniband/core/cma.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index ec473099e445..935f3979c8e2 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3467,8 +3467,13 @@ int rdma_listen(struct rdma_cm_id *id, int backlog)
 
 	id_priv = container_of(id, struct rdma_id_private, id);
 	if (id_priv->state == RDMA_CM_IDLE) {
-		id->route.addr.src_addr.ss_family = AF_INET;
-		ret = rdma_bind_addr(id, cma_src_addr(id_priv));
+		struct sockaddr_in any_in = {
+			.sin_family = AF_INET,
+			.sin_addr.s_addr = htonl(INADDR_ANY),
+		};
+
+		/* For a well behaved ULP state will be RDMA_CM_IDLE */
+		ret = rdma_bind_addr(id, (struct sockaddr *)&any_in);
 		if (ret)
 			return ret;
 	}
-- 
2.26.3