linux-stable.git/include/net, branch v4.4.199 Linux kernel stable tree sctp: fix the issue that flags are ignored when using kernel_connect 2019-11-06T11:09:25+00:00 Xin Long lucien.xin@gmail.com 2018-05-20T08:39:10+00:00 157fdfe11eeb063e30c2965ce98845e3ab1af43b commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream. Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags param can't be passed into its proto .connect where this flags is really needed. sctp works around it by getting flags from socket file in __sctp_connect. It works for connecting from userspace, as inherently the user sock has socket file and it passes f_flags as the flags param into the proto_ops .connect. However, the sock created by sock_create_kern doesn't have a socket file, and it passes the flags (like O_NONBLOCK) by using the flags param in kernel_connect, which calls proto_ops .connect later. So to fix it, this patch defines a new proto_ops .connect for sctp, sctp_inet_connect, which calls __sctp_connect() directly with this flags param. After this, the sctp's proto .connect can be removed. Note that sctp_inet_connect doesn't need to do some checks that are not needed for sctp, which makes thing better than with inet_dgram_connect. Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream.

Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags
param can't be passed into its proto .connect where this flags is really
needed.

sctp works around it by getting flags from socket file in __sctp_connect.
It works for connecting from userspace, as inherently the user sock has
socket file and it passes f_flags as the flags param into the proto_ops
.connect.

However, the sock created by sock_create_kern doesn't have a socket file,
and it passes the flags (like O_NONBLOCK) by using the flags param in
kernel_connect, which calls proto_ops .connect later.

So to fix it, this patch defines a new proto_ops .connect for sctp,
sctp_inet_connect, which calls __sctp_connect() directly with this
flags param. After this, the sctp's proto .connect can be removed.

Note that sctp_inet_connect doesn't need to do some checks that are not
needed for sctp, which makes thing better than with inet_dgram_connect.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sch_netem: fix rcu splat in netem_enqueue() 2019-11-06T11:09:24+00:00 Eric Dumazet edumazet@google.com 2019-09-24T20:11:26+00:00 09ee754c623344d6a94caf115e77ed74b4b2a702 commit 159d2c7d8106177bd9a986fd005a311fe0d11285 upstream. qdisc_root() use from netem_enqueue() triggers a lockdep warning. __dev_queue_xmit() uses rcu_read_lock_bh() which is not equivalent to rcu_read_lock() + local_bh_disable_bh as far as lockdep is concerned. WARNING: suspicious RCU usage 5.3.0-rc7+ #0 Not tainted ----------------------------- include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syz-executor427/8855: #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline] #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline] #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline] #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838 stack backtrace: CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357 qdisc_root include/net/sch_generic.h:492 [inline] netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479 __dev_xmit_skb net/core/dev.c:3527 [inline] __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 neigh_hh_output include/net/neighbour.h:500 [inline] neigh_output include/net/neighbour.h:509 [inline] ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:308 [inline] __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417 dst_output include/net/dst.h:436 [inline] ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 159d2c7d8106177bd9a986fd005a311fe0d11285 upstream.

qdisc_root() use from netem_enqueue() triggers a lockdep warning.

__dev_queue_xmit() uses rcu_read_lock_bh() which is
not equivalent to rcu_read_lock() + local_bh_disable_bh as far
as lockdep is concerned.

WARNING: suspicious RCU usage
5.3.0-rc7+ #0 Not tainted
-----------------------------
include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz-executor427/8855:
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline]
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214
 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838

stack backtrace:
CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357
 qdisc_root include/net/sch_generic.h:492 [inline]
 netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479
 __dev_xmit_skb net/core/dev.c:3527 [inline]
 __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290
 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125
 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555
 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887
 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174
 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
llc: fix sk_buff leak in llc_conn_service() 2019-11-06T11:09:22+00:00 Eric Biggers ebiggers@google.com 2019-10-06T21:24:25+00:00 96ff6ba50ab22c4004cb485f6cbabc75281ba5df commit b74555de21acd791f12c4a1aeaf653dd7ac21133 upstream. syzbot reported: BUG: memory leak unreferenced object 0xffff88811eb3de00 (size 224): comm "syz-executor559", pid 7315, jiffies 4294943019 (age 10.300s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 a0 38 24 81 88 ff ff 00 c0 f2 15 81 88 ff ff ..8$............ backtrace: [<000000008d1c66a1>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<000000008d1c66a1>] slab_post_alloc_hook mm/slab.h:439 [inline] [<000000008d1c66a1>] slab_alloc_node mm/slab.c:3269 [inline] [<000000008d1c66a1>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579 [<00000000447d9496>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198 [<000000000cdbf82f>] alloc_skb include/linux/skbuff.h:1058 [inline] [<000000000cdbf82f>] llc_alloc_frame+0x66/0x110 net/llc/llc_sap.c:54 [<000000002418b52e>] llc_conn_ac_send_sabme_cmd_p_set_x+0x2f/0x140 net/llc/llc_c_ac.c:777 [<000000001372ae17>] llc_exec_conn_trans_actions net/llc/llc_conn.c:475 [inline] [<000000001372ae17>] llc_conn_service net/llc/llc_conn.c:400 [inline] [<000000001372ae17>] llc_conn_state_process+0x1ac/0x640 net/llc/llc_conn.c:75 [<00000000f27e53c1>] llc_establish_connection+0x110/0x170 net/llc/llc_if.c:109 [<00000000291b2ca0>] llc_ui_connect+0x10e/0x370 net/llc/af_llc.c:477 [<000000000f9c740b>] __sys_connect+0x11d/0x170 net/socket.c:1840 [...] The bug is that most callers of llc_conn_send_pdu() assume it consumes a reference to the skb, when actually due to commit b85ab56c3f81 ("llc: properly handle dev_queue_xmit() return value") it doesn't. Revert most of that commit, and instead make the few places that need llc_conn_send_pdu() to *not* consume a reference call skb_get() before. Fixes: b85ab56c3f81 ("llc: properly handle dev_queue_xmit() return value") Reported-by: syzbot+6b825a6494a04cc0e3f7@syzkaller.appspotmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b74555de21acd791f12c4a1aeaf653dd7ac21133 upstream.

syzbot reported:

    BUG: memory leak
    unreferenced object 0xffff88811eb3de00 (size 224):
       comm "syz-executor559", pid 7315, jiffies 4294943019 (age 10.300s)
       hex dump (first 32 bytes):
         00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
         00 a0 38 24 81 88 ff ff 00 c0 f2 15 81 88 ff ff  ..8$............
       backtrace:
         [<000000008d1c66a1>] kmemleak_alloc_recursive  include/linux/kmemleak.h:55 [inline]
         [<000000008d1c66a1>] slab_post_alloc_hook mm/slab.h:439 [inline]
         [<000000008d1c66a1>] slab_alloc_node mm/slab.c:3269 [inline]
         [<000000008d1c66a1>] kmem_cache_alloc_node+0x153/0x2a0 mm/slab.c:3579
         [<00000000447d9496>] __alloc_skb+0x6e/0x210 net/core/skbuff.c:198
         [<000000000cdbf82f>] alloc_skb include/linux/skbuff.h:1058 [inline]
         [<000000000cdbf82f>] llc_alloc_frame+0x66/0x110 net/llc/llc_sap.c:54
         [<000000002418b52e>] llc_conn_ac_send_sabme_cmd_p_set_x+0x2f/0x140  net/llc/llc_c_ac.c:777
         [<000000001372ae17>] llc_exec_conn_trans_actions net/llc/llc_conn.c:475  [inline]
         [<000000001372ae17>] llc_conn_service net/llc/llc_conn.c:400 [inline]
         [<000000001372ae17>] llc_conn_state_process+0x1ac/0x640  net/llc/llc_conn.c:75
         [<00000000f27e53c1>] llc_establish_connection+0x110/0x170  net/llc/llc_if.c:109
         [<00000000291b2ca0>] llc_ui_connect+0x10e/0x370 net/llc/af_llc.c:477
         [<000000000f9c740b>] __sys_connect+0x11d/0x170 net/socket.c:1840
         [...]

The bug is that most callers of llc_conn_send_pdu() assume it consumes a
reference to the skb, when actually due to commit b85ab56c3f81 ("llc:
properly handle dev_queue_xmit() return value") it doesn't.

Revert most of that commit, and instead make the few places that need
llc_conn_send_pdu() to *not* consume a reference call skb_get() before.

Fixes: b85ab56c3f81 ("llc: properly handle dev_queue_xmit() return value")
Reported-by: syzbot+6b825a6494a04cc0e3f7@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xfrm: clean up xfrm protocol checks 2019-09-16T06:13:35+00:00 Cong Wang xiyou.wangcong@gmail.com 2019-03-22T23:26:19+00:00 e1b22f7a0b273e2b6ff50afe950f6161ca8e3e58 commit dbb2483b2a46fbaf833cfb5deb5ed9cace9c7399 upstream. In commit 6a53b7593233 ("xfrm: check id proto in validate_tmpl()") I introduced a check for xfrm protocol, but according to Herbert IPSEC_PROTO_ANY should only be used as a wildcard for lookup, so it should be removed from validate_tmpl(). And, IPSEC_PROTO_ANY is expected to only match 3 IPSec-specific protocols, this is why xfrm_state_flush() could still miss IPPROTO_ROUTING, which leads that those entries are left in net->xfrm.state_all before exit net. Fix this by replacing IPSEC_PROTO_ANY with zero. This patch also extracts the check from validate_tmpl() to xfrm_id_proto_valid() and uses it in parse_ipsecrequest(). With this, no other protocols should be added into xfrm. Fixes: 6a53b7593233 ("xfrm: check id proto in validate_tmpl()") Reported-by: syzbot+0bf0519d6e0de15914fe@syzkaller.appspotmail.com Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Zubin Mithra <zsm@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dbb2483b2a46fbaf833cfb5deb5ed9cace9c7399 upstream.

In commit 6a53b7593233 ("xfrm: check id proto in validate_tmpl()")
I introduced a check for xfrm protocol, but according to Herbert
IPSEC_PROTO_ANY should only be used as a wildcard for lookup, so
it should be removed from validate_tmpl().

And, IPSEC_PROTO_ANY is expected to only match 3 IPSec-specific
protocols, this is why xfrm_state_flush() could still miss
IPPROTO_ROUTING, which leads that those entries are left in
net->xfrm.state_all before exit net. Fix this by replacing
IPSEC_PROTO_ANY with zero.

This patch also extracts the check from validate_tmpl() to
xfrm_id_proto_valid() and uses it in parse_ipsecrequest().
With this, no other protocols should be added into xfrm.

Fixes: 6a53b7593233 ("xfrm: check id proto in validate_tmpl()")
Reported-by: syzbot+0bf0519d6e0de15914fe@syzkaller.appspotmail.com
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp: fix tcp_rtx_queue_tail in case of empty retransmit queue 2019-09-06T08:18:15+00:00 Tim Froidcoeur tim.froidcoeur@tessares.net 2019-08-24T06:03:51+00:00 1a48b39d1885a7a1fe92e96ada091b7b1ea6dd35 Commit 8c3088f895a0 ("tcp: be more careful in tcp_fragment()") triggers following stack trace: [25244.848046] kernel BUG at ./include/linux/skbuff.h:1406! [25244.859335] RIP: 0010:skb_queue_prev+0x9/0xc [25244.888167] Call Trace: [25244.889182] <IRQ> [25244.890001] tcp_fragment+0x9c/0x2cf [25244.891295] tcp_write_xmit+0x68f/0x988 [25244.892732] __tcp_push_pending_frames+0x3b/0xa0 [25244.894347] tcp_data_snd_check+0x2a/0xc8 [25244.895775] tcp_rcv_established+0x2a8/0x30d [25244.897282] tcp_v4_do_rcv+0xb2/0x158 [25244.898666] tcp_v4_rcv+0x692/0x956 [25244.899959] ip_local_deliver_finish+0xeb/0x169 [25244.901547] __netif_receive_skb_core+0x51c/0x582 [25244.903193] ? inet_gro_receive+0x239/0x247 [25244.904756] netif_receive_skb_internal+0xab/0xc6 [25244.906395] napi_gro_receive+0x8a/0xc0 [25244.907760] receive_buf+0x9a1/0x9cd [25244.909160] ? load_balance+0x17a/0x7b7 [25244.910536] ? vring_unmap_one+0x18/0x61 [25244.911932] ? detach_buf+0x60/0xfa [25244.913234] virtnet_poll+0x128/0x1e1 [25244.914607] net_rx_action+0x12a/0x2b1 [25244.915953] __do_softirq+0x11c/0x26b [25244.917269] ? handle_irq_event+0x44/0x56 [25244.918695] irq_exit+0x61/0xa0 [25244.919947] do_IRQ+0x9d/0xbb [25244.921065] common_interrupt+0x85/0x85 [25244.922479] </IRQ> tcp_rtx_queue_tail() (called by tcp_fragment()) can call tcp_write_queue_prev() on the first packet in the queue, which will trigger the BUG in tcp_write_queue_prev(), because there is no previous packet. This happens when the retransmit queue is empty, for example in case of a zero window. Commit 8c3088f895a0 ("tcp: be more careful in tcp_fragment()") was not a simple cherry-pick of the original one from master (b617158dc096) because there is a specific TCP rtx queue only since v4.15. For more details, please see the commit message of b617158dc096 ("tcp: be more careful in tcp_fragment()"). The BUG() is hit due to the specific code added to versions older than v4.15. The comment in skb_queue_prev() (include/linux/skbuff.h:1406), just before the BUG_ON() somehow suggests to add a check before using it, what Tim did. In master, this code path causing the issue will not be taken because the implementation of tcp_rtx_queue_tail() is different: tcp_fragment() → tcp_rtx_queue_tail() → tcp_write_queue_prev() → skb_queue_prev() → BUG_ON() Fixes: 8c3088f895a0 ("tcp: be more careful in tcp_fragment()") Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Reviewed-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
Commit 8c3088f895a0 ("tcp: be more careful in tcp_fragment()")
triggers following stack trace:

[25244.848046] kernel BUG at ./include/linux/skbuff.h:1406!
[25244.859335] RIP: 0010:skb_queue_prev+0x9/0xc
[25244.888167] Call Trace:
[25244.889182]  <IRQ>
[25244.890001]  tcp_fragment+0x9c/0x2cf
[25244.891295]  tcp_write_xmit+0x68f/0x988
[25244.892732]  __tcp_push_pending_frames+0x3b/0xa0
[25244.894347]  tcp_data_snd_check+0x2a/0xc8
[25244.895775]  tcp_rcv_established+0x2a8/0x30d
[25244.897282]  tcp_v4_do_rcv+0xb2/0x158
[25244.898666]  tcp_v4_rcv+0x692/0x956
[25244.899959]  ip_local_deliver_finish+0xeb/0x169
[25244.901547]  __netif_receive_skb_core+0x51c/0x582
[25244.903193]  ? inet_gro_receive+0x239/0x247
[25244.904756]  netif_receive_skb_internal+0xab/0xc6
[25244.906395]  napi_gro_receive+0x8a/0xc0
[25244.907760]  receive_buf+0x9a1/0x9cd
[25244.909160]  ? load_balance+0x17a/0x7b7
[25244.910536]  ? vring_unmap_one+0x18/0x61
[25244.911932]  ? detach_buf+0x60/0xfa
[25244.913234]  virtnet_poll+0x128/0x1e1
[25244.914607]  net_rx_action+0x12a/0x2b1
[25244.915953]  __do_softirq+0x11c/0x26b
[25244.917269]  ? handle_irq_event+0x44/0x56
[25244.918695]  irq_exit+0x61/0xa0
[25244.919947]  do_IRQ+0x9d/0xbb
[25244.921065]  common_interrupt+0x85/0x85
[25244.922479]  </IRQ>

tcp_rtx_queue_tail() (called by tcp_fragment()) can call
tcp_write_queue_prev() on the first packet in the queue, which will trigger
the BUG in tcp_write_queue_prev(), because there is no previous packet.

This happens when the retransmit queue is empty, for example in case of a
zero window.

Commit 8c3088f895a0 ("tcp: be more careful in tcp_fragment()") was not a
simple cherry-pick of the original one from master (b617158dc096)
because there is a specific TCP rtx queue only since v4.15. For more
details, please see the commit message of b617158dc096 ("tcp: be more
careful in tcp_fragment()").

The BUG() is hit due to the specific code added to versions older than
v4.15. The comment in skb_queue_prev() (include/linux/skbuff.h:1406),
just before the BUG_ON() somehow suggests to add a check before using
it, what Tim did.

In master, this code path causing the issue will not be taken because
the implementation of tcp_rtx_queue_tail() is different:

    tcp_fragment() → tcp_rtx_queue_tail() → tcp_write_queue_prev() →
skb_queue_prev() → BUG_ON()

Fixes: 8c3088f895a0 ("tcp: be more careful in tcp_fragment()")
Signed-off-by: Tim Froidcoeur <tim.froidcoeur@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: ctnetlink: don't use conntrack/expect object addresses as id 2019-09-06T08:18:13+00:00 Florian Westphal fw@strlen.de 2019-08-27T23:11:12+00:00 36bbd861a402a8c5bd8f0365a5967d34cc492f09 commit 3c79107631db1f7fd32cf3f7368e4672004a3010 upstream. else, we leak the addresses to userspace via ctnetlink events and dumps. Compute an ID on demand based on the immutable parts of nf_conn struct. Another advantage compared to using an address is that there is no immediate re-use of the same ID in case the conntrack entry is freed and reallocated again immediately. Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID") Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit 3c79107631db1f7fd32cf3f7368e4672004a3010 upstream.

else, we leak the addresses to userspace via ctnetlink events
and dumps.

Compute an ID on demand based on the immutable parts of nf_conn struct.

Another advantage compared to using an address is that there is no
immediate re-use of the same ID in case the conntrack entry is freed and
reallocated again immediately.

Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID")
Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
inet: switch IP ID generator to siphash 2019-09-06T08:18:13+00:00 Eric Dumazet edumazet@google.com 2019-08-27T23:11:06+00:00 66f8c5ff8ed3d99dd21d8f24aac89410de7a4a05 commit df453700e8d81b1bdafdf684365ee2b9431fb702 upstream. According to Amit Klein and Benny Pinkas, IP ID generation is too weak and might be used by attackers. Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix()) having 64bit key and Jenkins hash is risky. It is time to switch to siphash and its 128bit keys. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Amit Klein <aksecurity@gmail.com> Reported-by: Benny Pinkas <benny@pinkas.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Sasha Levin <sashal@kernel.org> 
commit df453700e8d81b1bdafdf684365ee2b9431fb702 upstream.

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.4: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: be more careful in tcp_fragment() 2019-08-11T10:20:43+00:00 Eric Dumazet edumazet@google.com 2019-08-06T15:09:14+00:00 5917ca48053447dac0e13c51ed7d4e2471a1cbc9 [ Upstream commit b617158dc096709d8600c53b6052144d12b89fab ] Some applications set tiny SO_SNDBUF values and expect TCP to just work. Recent patches to address CVE-2019-11478 broke them in case of losses, since retransmits might be prevented. We should allow these flows to make progress. This patch allows the first and last skb in retransmit queue to be split even if memory limits are hit. It also adds the some room due to the fact that tcp_sendmsg() and tcp_sendpage() might overshoot sk_wmem_queued by about one full TSO skb (64KB size). Note this allowance was already present in stable backports for kernels < 4.15 Note for < 4.15 backports : tcp_rtx_queue_tail() will probably look like : static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) { struct sk_buff *skb = tcp_send_head(sk); return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk); } Fixes: f070ef2ac667 ("tcp: tcp_fragment() should apply sane memory limits") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrew Prout <aprout@ll.mit.edu> Tested-by: Andrew Prout <aprout@ll.mit.edu> Tested-by: Jonathan Lemon <jonathan.lemon@gmail.com> Tested-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Christoph Paasch <cpaasch@apple.com> Cc: Jonathan Looney <jtl@netflix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b617158dc096709d8600c53b6052144d12b89fab ]

Some applications set tiny SO_SNDBUF values and expect
TCP to just work. Recent patches to address CVE-2019-11478
broke them in case of losses, since retransmits might
be prevented.

We should allow these flows to make progress.

This patch allows the first and last skb in retransmit queue
to be split even if memory limits are hit.

It also adds the some room due to the fact that tcp_sendmsg()
and tcp_sendpage() might overshoot sk_wmem_queued by about one full
TSO skb (64KB size). Note this allowance was already present
in stable backports for kernels < 4.15

Note for < 4.15 backports :
 tcp_rtx_queue_tail() will probably look like :

static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk)
{
	struct sk_buff *skb = tcp_send_head(sk);

	return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk);
}

Fixes: f070ef2ac667 ("tcp: tcp_fragment() should apply sane memory limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Christoph Paasch <cpaasch@apple.com>
Cc: Jonathan Looney <jtl@netflix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: reset sk_send_head in tcp_write_queue_purge 2019-08-04T07:35:01+00:00 Soheil Hassas Yeganeh soheil@google.com 2019-07-29T13:21:08+00:00 8f0b77b71f3fec09f86f80cd98c36a1a35109499 [ Upstream commit dbbf2d1e4077bab0c65ece2765d3fc69cf7d610f ] tcp_write_queue_purge clears all the SKBs in the write queue but does not reset the sk_send_head. As a result, we can have a NULL pointer dereference anywhere that we use tcp_send_head instead of the tcp_write_queue_tail. For example, after a27fd7a8ed38 (tcp: purge write queue upon RST), we can purge the write queue on RST. Prior to 75c119afe14f (tcp: implement rb-tree based retransmit queue), tcp_push will only check tcp_send_head and then accesses tcp_write_queue_tail to send the actual SKB. As a result, it will dereference a NULL pointer. This has been reported twice for 4.14 where we don't have 75c119afe14f: By Timofey Titovets: [ 422.081094] BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 [ 422.081254] IP: tcp_push+0x42/0x110 [ 422.081314] PGD 0 P4D 0 [ 422.081364] Oops: 0002 [#1] SMP PTI By Yongjian Xu: BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: tcp_push+0x48/0x120 PGD 80000007ff77b067 P4D 80000007ff77b067 PUD 7fd989067 PMD 0 Oops: 0002 [#18] SMP PTI Modules linked in: tcp_diag inet_diag tcp_bbr sch_fq iTCO_wdt iTCO_vendor_support pcspkr ixgbe mdio i2c_i801 lpc_ich joydev input_leds shpchp e1000e igb dca ptp pps_core hwmon mei_me mei ipmi_si ipmi_msghandler sg ses scsi_transport_sas enclosure ext4 jbd2 mbcache sd_mod ahci libahci megaraid_sas wmi ast ttm dm_mirror dm_region_hash dm_log dm_mod dax CPU: 6 PID: 14156 Comm: [ET_NET 6] Tainted: G D 4.14.26-1.el6.x86_64 #1 Hardware name: LENOVO ThinkServer RD440 /ThinkServer RD440, BIOS A0TS80A 09/22/2014 task: ffff8807d78d8140 task.stack: ffffc9000e944000 RIP: 0010:tcp_push+0x48/0x120 RSP: 0018:ffffc9000e947a88 EFLAGS: 00010246 RAX: 00000000000005b4 RBX: ffff880f7cce9c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff8807d00f5000 RBP: ffffc9000e947aa8 R08: 0000000000001c84 R09: 0000000000000000 R10: ffff8807d00f5158 R11: 0000000000000000 R12: ffff8807d00f5000 R13: 0000000000000020 R14: 00000000000256d4 R15: 0000000000000000 FS: 00007f5916de9700(0000) GS:ffff88107fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 00000007f8226004 CR4: 00000000001606e0 Call Trace: tcp_sendmsg_locked+0x33d/0xe50 tcp_sendmsg+0x37/0x60 inet_sendmsg+0x39/0xc0 sock_sendmsg+0x49/0x60 sock_write_iter+0xb6/0x100 do_iter_readv_writev+0xec/0x130 ? rw_verify_area+0x49/0xb0 do_iter_write+0x97/0xd0 vfs_writev+0x7e/0xe0 ? __wake_up_common_lock+0x80/0xa0 ? __fget_light+0x2c/0x70 ? __do_page_fault+0x1e7/0x530 do_writev+0x60/0xf0 ? inet_shutdown+0xac/0x110 SyS_writev+0x10/0x20 do_syscall_64+0x6f/0x140 ? prepare_exit_to_usermode+0x8b/0xa0 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x3135ce0c57 RSP: 002b:00007f5916de4b00 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000003135ce0c57 RDX: 0000000000000002 RSI: 00007f5916de4b90 RDI: 000000000000606f RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f5916de8c38 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000464cc R13: 00007f5916de8c30 R14: 00007f58d8bef080 R15: 0000000000000002 Code: 48 8b 97 60 01 00 00 4c 8d 97 58 01 00 00 41 b9 00 00 00 00 41 89 f3 4c 39 d2 49 0f 44 d1 41 81 e3 00 80 00 00 0f 85 b0 00 00 00 <80> 4a 38 08 44 8b 8f 74 06 00 00 44 89 8f 7c 06 00 00 83 e6 01 RIP: tcp_push+0x48/0x120 RSP: ffffc9000e947a88 CR2: 0000000000000038 ---[ end trace 8d545c2e93515549 ]--- There is other scenario which found in stable 4.4: Allocated: [<ffffffff82f380a6>] __alloc_skb+0xe6/0x600 net/core/skbuff.c:218 [<ffffffff832466c3>] alloc_skb_fclone include/linux/skbuff.h:856 [inline] [<ffffffff832466c3>] sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:833 [<ffffffff83249164>] tcp_sendmsg+0xd34/0x2b00 net/ipv4/tcp.c:1178 [<ffffffff83300ef3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755 Freed: [<ffffffff82f372fd>] __kfree_skb+0x1d/0x20 net/core/skbuff.c:676 [<ffffffff83288834>] sk_wmem_free_skb include/net/sock.h:1447 [inline] [<ffffffff83288834>] tcp_write_queue_purge include/net/tcp.h:1460 [inline] [<ffffffff83288834>] tcp_connect_init net/ipv4/tcp_output.c:3122 [inline] [<ffffffff83288834>] tcp_connect+0xb24/0x30c0 net/ipv4/tcp_output.c:3261 [<ffffffff8329b991>] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246 BUG: KASAN: use-after-free in tcp_skb_pcount include/net/tcp.h:796 [inline] BUG: KASAN: use-after-free in tcp_init_tso_segs net/ipv4/tcp_output.c:1619 [inline] BUG: KASAN: use-after-free in tcp_write_xmit+0x3fc2/0x4cb0 net/ipv4/tcp_output.c:2056 [<ffffffff81515cd5>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408 [<ffffffff814f9784>] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427 [<ffffffff83286582>] tcp_skb_pcount include/net/tcp.h:796 [inline] [<ffffffff83286582>] tcp_init_tso_segs net/ipv4/tcp_output.c:1619 [inline] [<ffffffff83286582>] tcp_write_xmit+0x3fc2/0x4cb0 net/ipv4/tcp_output.c:2056 [<ffffffff83287a40>] __tcp_push_pending_frames+0xa0/0x290 net/ipv4/tcp_output.c:2307 stable 4.4 and stable 4.9 don't have the commit abb4a8b870b5 ("tcp: purge write queue upon RST") which is referred in dbbf2d1e4077, in tcp_connect_init, it calls tcp_write_queue_purge, and does not reset sk_send_head, then UAF. stable 4.14 have the commit abb4a8b870b5 ("tcp: purge write queue upon RST"), in tcp_reset, it calls tcp_write_queue_purge(sk), and does not reset sk_send_head, then UAF. So this patch can be used to fix stable 4.4 and 4.9. Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST) Reported-by: Timofey Titovets <nefelim4ag@gmail.com> Reported-by: Yongjian Xu <yongjianchn@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Tested-by: Yongjian Xu <yongjianchn@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit dbbf2d1e4077bab0c65ece2765d3fc69cf7d610f ]

tcp_write_queue_purge clears all the SKBs in the write queue
but does not reset the sk_send_head. As a result, we can have
a NULL pointer dereference anywhere that we use tcp_send_head
instead of the tcp_write_queue_tail.

For example, after a27fd7a8ed38 (tcp: purge write queue upon RST),
we can purge the write queue on RST. Prior to
75c119afe14f (tcp: implement rb-tree based retransmit queue),
tcp_push will only check tcp_send_head and then accesses
tcp_write_queue_tail to send the actual SKB. As a result, it will
dereference a NULL pointer.

This has been reported twice for 4.14 where we don't have
75c119afe14f:

By Timofey Titovets:

[  422.081094] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000038
[  422.081254] IP: tcp_push+0x42/0x110
[  422.081314] PGD 0 P4D 0
[  422.081364] Oops: 0002 [#1] SMP PTI

By Yongjian Xu:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: tcp_push+0x48/0x120
PGD 80000007ff77b067 P4D 80000007ff77b067 PUD 7fd989067 PMD 0
Oops: 0002 [#18] SMP PTI
Modules linked in: tcp_diag inet_diag tcp_bbr sch_fq iTCO_wdt
iTCO_vendor_support pcspkr ixgbe mdio i2c_i801 lpc_ich joydev input_leds shpchp
e1000e igb dca ptp pps_core hwmon mei_me mei ipmi_si ipmi_msghandler sg ses
scsi_transport_sas enclosure ext4 jbd2 mbcache sd_mod ahci libahci megaraid_sas
wmi ast ttm dm_mirror dm_region_hash dm_log dm_mod dax
CPU: 6 PID: 14156 Comm: [ET_NET 6] Tainted: G D 4.14.26-1.el6.x86_64 #1
Hardware name: LENOVO ThinkServer RD440 /ThinkServer RD440, BIOS A0TS80A
09/22/2014
task: ffff8807d78d8140 task.stack: ffffc9000e944000
RIP: 0010:tcp_push+0x48/0x120
RSP: 0018:ffffc9000e947a88 EFLAGS: 00010246
RAX: 00000000000005b4 RBX: ffff880f7cce9c00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff8807d00f5000
RBP: ffffc9000e947aa8 R08: 0000000000001c84 R09: 0000000000000000
R10: ffff8807d00f5158 R11: 0000000000000000 R12: ffff8807d00f5000
R13: 0000000000000020 R14: 00000000000256d4 R15: 0000000000000000
FS: 00007f5916de9700(0000) GS:ffff88107fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 00000007f8226004 CR4: 00000000001606e0
Call Trace:
tcp_sendmsg_locked+0x33d/0xe50
tcp_sendmsg+0x37/0x60
inet_sendmsg+0x39/0xc0
sock_sendmsg+0x49/0x60
sock_write_iter+0xb6/0x100
do_iter_readv_writev+0xec/0x130
? rw_verify_area+0x49/0xb0
do_iter_write+0x97/0xd0
vfs_writev+0x7e/0xe0
? __wake_up_common_lock+0x80/0xa0
? __fget_light+0x2c/0x70
? __do_page_fault+0x1e7/0x530
do_writev+0x60/0xf0
? inet_shutdown+0xac/0x110
SyS_writev+0x10/0x20
do_syscall_64+0x6f/0x140
? prepare_exit_to_usermode+0x8b/0xa0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x3135ce0c57
RSP: 002b:00007f5916de4b00 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000003135ce0c57
RDX: 0000000000000002 RSI: 00007f5916de4b90 RDI: 000000000000606f
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f5916de8c38
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000464cc
R13: 00007f5916de8c30 R14: 00007f58d8bef080 R15: 0000000000000002
Code: 48 8b 97 60 01 00 00 4c 8d 97 58 01 00 00 41 b9 00 00 00 00 41 89 f3 4c 39
d2 49 0f 44 d1 41 81 e3 00 80 00 00 0f 85 b0 00 00 00 <80> 4a 38 08 44 8b 8f 74
06 00 00 44 89 8f 7c 06 00 00 83 e6 01
RIP: tcp_push+0x48/0x120 RSP: ffffc9000e947a88
CR2: 0000000000000038
---[ end trace 8d545c2e93515549 ]---

There is other scenario which found in stable 4.4:
Allocated:
 [<ffffffff82f380a6>] __alloc_skb+0xe6/0x600 net/core/skbuff.c:218
 [<ffffffff832466c3>] alloc_skb_fclone include/linux/skbuff.h:856 [inline]
 [<ffffffff832466c3>] sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:833
 [<ffffffff83249164>] tcp_sendmsg+0xd34/0x2b00 net/ipv4/tcp.c:1178
 [<ffffffff83300ef3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
Freed:
 [<ffffffff82f372fd>] __kfree_skb+0x1d/0x20 net/core/skbuff.c:676
 [<ffffffff83288834>] sk_wmem_free_skb include/net/sock.h:1447 [inline]
 [<ffffffff83288834>] tcp_write_queue_purge include/net/tcp.h:1460 [inline]
 [<ffffffff83288834>] tcp_connect_init net/ipv4/tcp_output.c:3122 [inline]
 [<ffffffff83288834>] tcp_connect+0xb24/0x30c0 net/ipv4/tcp_output.c:3261
 [<ffffffff8329b991>] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246

BUG: KASAN: use-after-free in tcp_skb_pcount include/net/tcp.h:796 [inline]
BUG: KASAN: use-after-free in tcp_init_tso_segs net/ipv4/tcp_output.c:1619 [inline]
BUG: KASAN: use-after-free in tcp_write_xmit+0x3fc2/0x4cb0 net/ipv4/tcp_output.c:2056
 [<ffffffff81515cd5>] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff814f9784>] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427
 [<ffffffff83286582>] tcp_skb_pcount include/net/tcp.h:796 [inline]
 [<ffffffff83286582>] tcp_init_tso_segs net/ipv4/tcp_output.c:1619 [inline]
 [<ffffffff83286582>] tcp_write_xmit+0x3fc2/0x4cb0 net/ipv4/tcp_output.c:2056
 [<ffffffff83287a40>] __tcp_push_pending_frames+0xa0/0x290 net/ipv4/tcp_output.c:2307

stable 4.4 and stable 4.9 don't have the commit abb4a8b870b5 ("tcp: purge write queue upon RST")
which is referred in dbbf2d1e4077,
in tcp_connect_init, it calls tcp_write_queue_purge, and does not reset sk_send_head, then UAF.

stable 4.14 have the commit abb4a8b870b5 ("tcp: purge write queue upon RST"),
in tcp_reset, it calls tcp_write_queue_purge(sk), and does not reset sk_send_head, then UAF.

So this patch can be used to fix stable 4.4 and 4.9.

Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST)
Reported-by: Timofey Titovets <nefelim4ag@gmail.com>
Reported-by: Yongjian Xu <yongjianchn@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Tested-by: Yongjian Xu <yongjianchn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: check before dereferencing netdev_ops during busy poll 2019-07-10T07:56:38+00:00 Josh Elsasser jelsasser@appneta.com 2019-07-01T23:48:47+00:00 b3c963d51a02153ffd7c2c41ed4a9287c9d25da2 init_dummy_netdev() leaves its netdev_ops pointer zeroed. This leads to a NULL pointer dereference when sk_busy_loop fires against an iwlwifi wireless adapter and checks napi->dev->netdev_ops->ndo_busy_poll. Avoid this by ensuring napi->dev->netdev_ops is valid before following the pointer, avoiding the following panic when busy polling on a dummy netdev: BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 IP: [<ffffffff817b4b72>] sk_busy_loop+0x92/0x2f0 Call Trace: [<ffffffff815a3134>] ? uart_write_room+0x74/0xf0 [<ffffffff817964a9>] sock_poll+0x99/0xa0 [<ffffffff81223142>] do_sys_poll+0x2e2/0x520 [<ffffffff8118d3fc>] ? get_page_from_freelist+0x3bc/0xa30 [<ffffffff810ada22>] ? update_curr+0x62/0x140 [<ffffffff811ea671>] ? __slab_free+0xa1/0x2a0 [<ffffffff811ea671>] ? __slab_free+0xa1/0x2a0 [<ffffffff8179dbb1>] ? skb_free_head+0x21/0x30 [<ffffffff81221bd0>] ? poll_initwait+0x50/0x50 [<ffffffff811eaa36>] ? kmem_cache_free+0x1c6/0x1e0 [<ffffffff815a4884>] ? uart_write+0x124/0x1d0 [<ffffffff810bd1cd>] ? remove_wait_queue+0x4d/0x60 [<ffffffff810bd224>] ? __wake_up+0x44/0x50 [<ffffffff81582731>] ? tty_write_unlock+0x31/0x40 [<ffffffff8158c5c6>] ? tty_ldisc_deref+0x16/0x20 [<ffffffff81584820>] ? tty_write+0x1e0/0x2f0 [<ffffffff81587e50>] ? process_echoes+0x80/0x80 [<ffffffff8120c17b>] ? __vfs_write+0x2b/0x130 [<ffffffff8120d09a>] ? vfs_write+0x15a/0x1a0 [<ffffffff81223455>] SyS_poll+0x75/0x100 [<ffffffff819a6524>] entry_SYSCALL_64_fastpath+0x24/0xcf Commit 79e7fff47b7b ("net: remove support for per driver ndo_busy_poll()") indirectly fixed this upstream in linux-4.11 by removing the offending pointer usage. No other users of napi->dev touch its netdev_ops. Fixes: 8b80cda536ea ("net: rename include/net/ll_poll.h to include/net/busy_poll.h") # 4.4.y Signed-off-by: Josh Elsasser <jelsasser@appneta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
init_dummy_netdev() leaves its netdev_ops pointer zeroed. This leads
to a NULL pointer dereference when sk_busy_loop fires against an iwlwifi
wireless adapter and checks napi->dev->netdev_ops->ndo_busy_poll.

Avoid this by ensuring napi->dev->netdev_ops is valid before following
the pointer, avoiding the following panic when busy polling on a dummy
netdev:

  BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8
  IP: [<ffffffff817b4b72>] sk_busy_loop+0x92/0x2f0
  Call Trace:
   [<ffffffff815a3134>] ? uart_write_room+0x74/0xf0
   [<ffffffff817964a9>] sock_poll+0x99/0xa0
   [<ffffffff81223142>] do_sys_poll+0x2e2/0x520
   [<ffffffff8118d3fc>] ? get_page_from_freelist+0x3bc/0xa30
   [<ffffffff810ada22>] ? update_curr+0x62/0x140
   [<ffffffff811ea671>] ? __slab_free+0xa1/0x2a0
   [<ffffffff811ea671>] ? __slab_free+0xa1/0x2a0
   [<ffffffff8179dbb1>] ? skb_free_head+0x21/0x30
   [<ffffffff81221bd0>] ? poll_initwait+0x50/0x50
   [<ffffffff811eaa36>] ? kmem_cache_free+0x1c6/0x1e0
   [<ffffffff815a4884>] ? uart_write+0x124/0x1d0
   [<ffffffff810bd1cd>] ? remove_wait_queue+0x4d/0x60
   [<ffffffff810bd224>] ? __wake_up+0x44/0x50
   [<ffffffff81582731>] ? tty_write_unlock+0x31/0x40
   [<ffffffff8158c5c6>] ? tty_ldisc_deref+0x16/0x20
   [<ffffffff81584820>] ? tty_write+0x1e0/0x2f0
   [<ffffffff81587e50>] ? process_echoes+0x80/0x80
   [<ffffffff8120c17b>] ? __vfs_write+0x2b/0x130
   [<ffffffff8120d09a>] ? vfs_write+0x15a/0x1a0
   [<ffffffff81223455>] SyS_poll+0x75/0x100
   [<ffffffff819a6524>] entry_SYSCALL_64_fastpath+0x24/0xcf

Commit 79e7fff47b7b ("net: remove support for per driver ndo_busy_poll()")
indirectly fixed this upstream in linux-4.11 by removing the offending
pointer usage. No other users of napi->dev touch its netdev_ops.

Fixes: 8b80cda536ea ("net: rename include/net/ll_poll.h to include/net/busy_poll.h") # 4.4.y
Signed-off-by: Josh Elsasser <jelsasser@appneta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>