From f1b204001d44fb5fd7d8255f9fe43639698114d5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 13 Apr 2022 10:35:41 -0700 Subject: [PATCH 1/2] net/sched: cls_u32: fix netns refcount changes in u32_change() stable inclusion from stable-v4.19.241 commit 75b0cc7904da7b40c6e8f2cf3ec4223b292b1184 category: bugfix issue: CVE: CVE-2022-29581 Signed-off-by: wanxiaoqing40281 --------------------------------------- commit 3db09e762dc79584a69c10d74a6b98f89a9979f8 upstream. We are now able to detect extra put_net() at the moment they happen, instead of much later in correct code paths. u32_init_knode() / tcf_exts_init() populates the ->exts.net pointer, but as mentioned in tcf_exts_init(), the refcount on netns has not been elevated yet. The refcount is taken only once tcf_exts_get_net() is called. So the two u32_destroy_key() calls from u32_change() are attempting to release an invalid reference on the netns. syzbot report: refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 0 PID: 21708 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Modules linked in: CPU: 0 PID: 21708 Comm: syz-executor.5 Not tainted 5.18.0-rc2-next-20220412-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31 Code: 1d 14 b6 b2 09 31 ff 89 de e8 6d e9 89 fd 84 db 75 e0 e8 84 e5 89 fd 48 c7 c7 40 aa 26 8a c6 05 f4 b5 b2 09 01 e8 e5 81 2e 05 <0f> 0b eb c4 e8 68 e5 89 fd 0f b6 1d e3 b5 b2 09 31 ff 89 de e8 38 RSP: 0018:ffffc900051af1b0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff8160a0c8 RDI: fffff52000a35e28 RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81604a9e R11: 0000000000000000 R12: 1ffff92000a35e3b R13: 00000000ffffffef R14: ffff8880211a0194 R15: ffff8880577d0a00 FS: 00007f25d183e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f19c859c028 CR3: 0000000051009000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] ref_tracker_free+0x535/0x6b0 lib/ref_tracker.c:118 netns_tracker_free include/net/net_namespace.h:327 [inline] put_net_track include/net/net_namespace.h:341 [inline] tcf_exts_put_net include/net/pkt_cls.h:255 [inline] u32_destroy_key.isra.0+0xa7/0x2b0 net/sched/cls_u32.c:394 u32_change+0xe01/0x3140 net/sched/cls_u32.c:909 tc_new_tfilter+0x98d/0x2200 net/sched/cls_api.c:2148 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:6016 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2495 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f25d0689049 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f25d183e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f25d079c030 RCX: 00007f25d0689049 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000005 RBP: 00007f25d06e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd0b752e3f R14: 00007f25d183e300 R15: 0000000000022000 Fixes: 35c55fc156d8 ("cls_u32: use tcf_exts_get_net() before call_rcu()") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Cong Wang Cc: Jiri Pirko Acked-by: Jamal Hadi Salim Signed-off-by: Jakub Kicinski [rkolchmeyer: Backported to 4.19: adjusted u32_destroy_key() signature] Signed-off-by: Robert Kolchmeyer Signed-off-by: Greg Kroah-Hartman Signed-off-by: wanxiaoqing40281 --- net/sched/cls_u32.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index fe246e03fcd9..ad82c6309482 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -404,15 +404,20 @@ static int u32_init(struct tcf_proto *tp) return 0; } -static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n, - bool free_pf) +static void __u32_destroy_key(struct tc_u_knode *n) { struct tc_u_hnode *ht = rtnl_dereference(n->ht_down); tcf_exts_destroy(&n->exts); - tcf_exts_put_net(&n->exts); if (ht && --ht->refcnt == 0) kfree(ht); + kfree(n); +} + +static void u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n, + bool free_pf) +{ + tcf_exts_put_net(&n->exts); #ifdef CONFIG_CLS_U32_PERF if (free_pf) free_percpu(n->pf); @@ -421,8 +426,7 @@ static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n, if (free_pf) free_percpu(n->pcpu_success); #endif - kfree(n); - return 0; + __u32_destroy_key(n); } /* u32_delete_key_rcu should be called when free'ing a copied @@ -965,13 +969,13 @@ static int u32_change(struct net *net, struct sk_buff *in_skb, tca[TCA_RATE], ovr, extack); if (err) { - u32_destroy_key(tp, new, false); + __u32_destroy_key(new); return err; } err = u32_replace_hw_knode(tp, new, flags, extack); if (err) { - u32_destroy_key(tp, new, false); + __u32_destroy_key(new); return err; } -- Gitee From ab77eb6c16f75dbf1d0061ca23ef60d7e5229fb4 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 16 May 2022 16:42:13 +0800 Subject: [PATCH 2/2] Fix double fget() in vhost_net_set_backend() stable inclusion from stable-v4.19.245 commit 6ca70982c646cc32e458150ee7f2530a24369b8c category: bugfix issue: CVE: CVE-2023-1838 Signed-off-by: wanxiaoqing40281 --------------------------------------- commit fb4554c2232e44d595920f4d5c66cf8f7d13f9bc upstream. Descriptor table is a shared resource; two fget() on the same descriptor may return different struct file references. get_tap_ptr_ring() is called after we'd found (and pinned) the socket we'll be using and it tries to find the private tun/tap data structures associated with it. Redoing the lookup by the same file descriptor we'd used to get the socket is racy - we need to same struct file. Thanks to Jason for spotting a braino in the original variant of patch - I'd missed the use of fd == -1 for disabling backend, and in that case we can end up with sock == NULL and sock != oldsock. Cc: stable@kernel.org Acked-by: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman Signed-off-by: wanxiaoqing40281 --- drivers/vhost/net.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 88c8c158ec25..51901a5629ce 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1209,13 +1209,9 @@ static struct socket *get_raw_socket(int fd) return ERR_PTR(r); } -static struct ptr_ring *get_tap_ptr_ring(int fd) +static struct ptr_ring *get_tap_ptr_ring(struct file *file) { struct ptr_ring *ring; - struct file *file = fget(fd); - - if (!file) - return NULL; ring = tun_get_tx_ring(file); if (!IS_ERR(ring)) goto out; @@ -1224,7 +1220,6 @@ static struct ptr_ring *get_tap_ptr_ring(int fd) goto out; ring = NULL; out: - fput(file); return ring; } @@ -1311,8 +1306,12 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) r = vhost_net_enable_vq(n, vq); if (r) goto err_used; - if (index == VHOST_NET_VQ_RX) - nvq->rx_ring = get_tap_ptr_ring(fd); + if (index == VHOST_NET_VQ_RX) { + if (sock) + nvq->rx_ring = get_tap_ptr_ring(sock->file); + else + nvq->rx_ring = NULL; + } oldubufs = nvq->ubufs; nvq->ubufs = ubufs; -- Gitee