linux-stable.git/net, branch v4.17.6 Linux kernel stable tree netfilter: nf_log: don't hold nf_log_mutex during user access 2018-07-11T14:31:34+00:00 Jann Horn jannh@google.com 2018-06-25T15:22:00+00:00 362aa587f6129c27153de857e0c039ed81c968fb commit ce00bf07cc95a57cd20b208e02b3c2604e532ae8 upstream. The old code would indefinitely block other users of nf_log_mutex if a userspace access in proc_dostring() blocked e.g. due to a userfaultfd region. Fix it by moving proc_dostring() out of the locked region. This is a followup to commit 266d07cb1c9a ("netfilter: nf_log: fix sleeping function called from invalid context"), which changed this code from using rcu_read_lock() to taking nf_log_mutex. Fixes: 266d07cb1c9a ("netfilter: nf_log: fix sleeping function calle[...]") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ce00bf07cc95a57cd20b208e02b3c2604e532ae8 upstream.

The old code would indefinitely block other users of nf_log_mutex if
a userspace access in proc_dostring() blocked e.g. due to a userfaultfd
region. Fix it by moving proc_dostring() out of the locked region.

This is a followup to commit 266d07cb1c9a ("netfilter: nf_log: fix
sleeping function called from invalid context"), which changed this code
from using rcu_read_lock() to taking nf_log_mutex.

Fixes: 266d07cb1c9a ("netfilter: nf_log: fix sleeping function calle[...]")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: nf_tables: use WARN_ON_ONCE instead of BUG_ON in nft_do_chain() 2018-07-08T13:32:21+00:00 Taehee Yoo ap420073@gmail.com 2018-06-11T13:16:33+00:00 012007a1dd19a437583a7b45018aaef14642093c commit adc972c5b88829d38ede08b1069718661c7330ae upstream. When depth of chain is bigger than NFT_JUMP_STACK_SIZE, the nft_do_chain crashes. But there is no need to crash hard here. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Taehee Yoo <ap420073@gmail.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit adc972c5b88829d38ede08b1069718661c7330ae upstream.

When depth of chain is bigger than NFT_JUMP_STACK_SIZE, the nft_do_chain
crashes. But there is no need to crash hard here.

Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: xt_connmark: fix list corruption on rmmod 2018-07-08T13:32:21+00:00 Florian Westphal fw@strlen.de 2018-06-12T16:36:19+00:00 735c001bfb3bcf07eb2ea006a99ddcd90d864fad commit fc6ddbecce440df74fb4491c17c372b52cf5be83 upstream. This needs to use xt_unregister_targets, else new revision is left on the list which then causes list to point to a target struct that has been free'd. Fixes: 472a73e00757 ("netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fc6ddbecce440df74fb4491c17c372b52cf5be83 upstream.

This needs to use xt_unregister_targets, else new revision is left
on the list which then causes list to point to a target struct that has been free'd.

Fixes: 472a73e00757 ("netfilter: xt_conntrack: Support bit-shifting for CONNMARK & MARK targets.")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: ip6t_rpfilter: provide input interface for route lookup 2018-07-08T13:32:20+00:00 Vincent Bernat vincent@bernat.im 2018-05-20T11:03:38+00:00 33e021ba64e9d9c7e8b6c5faa328996c83531261 commit cede24d1b21d68d84ac5a36c44f7d37daadcc258 upstream. In commit 47b7e7f82802, this bit was removed at the same time the RT6_LOOKUP_F_IFACE flag was removed. However, it is needed when link-local addresses are used, which is a very common case: when packets are routed, neighbor solicitations are done using link-local addresses. For example, the following neighbor solicitation is not matched by "-m rpfilter": IP6 fe80::5254:33ff:fe00:1 > ff02::1:ff00:3: ICMP6, neighbor solicitation, who has 2001:db8::5254:33ff:fe00:3, length 32 Commit 47b7e7f82802 doesn't quite explain why we shouldn't use RT6_LOOKUP_F_IFACE in the rpfilter case. I suppose the interface check later in the function would make it redundant. However, the remaining of the routing code is using RT6_LOOKUP_F_IFACE when there is no source address (which matches rpfilter's case with a non-unicast destination, like with neighbor solicitation). Signed-off-by: Vincent Bernat <vincent@bernat.im> Fixes: 47b7e7f82802 ("netfilter: don't set F_IFACE on ipv6 fib lookups") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cede24d1b21d68d84ac5a36c44f7d37daadcc258 upstream.

In commit 47b7e7f82802, this bit was removed at the same time the
RT6_LOOKUP_F_IFACE flag was removed. However, it is needed when
link-local addresses are used, which is a very common case: when
packets are routed, neighbor solicitations are done using link-local
addresses. For example, the following neighbor solicitation is not
matched by "-m rpfilter":

    IP6 fe80::5254:33ff:fe00:1 > ff02::1:ff00:3: ICMP6, neighbor
    solicitation, who has 2001:db8::5254:33ff:fe00:3, length 32

Commit 47b7e7f82802 doesn't quite explain why we shouldn't use
RT6_LOOKUP_F_IFACE in the rpfilter case. I suppose the interface check
later in the function would make it redundant. However, the remaining
of the routing code is using RT6_LOOKUP_F_IFACE when there is no
source address (which matches rpfilter's case with a non-unicast
destination, like with neighbor solicitation).

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Fixes: 47b7e7f82802 ("netfilter: don't set F_IFACE on ipv6 fib lookups")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xprtrdma: Return -ENOBUFS when no pages are available 2018-07-03T09:26:56+00:00 Chuck Lever chuck.lever@oracle.com 2018-05-04T19:35:46+00:00 e9b7f6ccdf30e4fce1fd418ab4b012afb0bc2400 commit a8f688ec437dc2045cc8f0c89fe877d5803850da upstream. The use of -EAGAIN in rpcrdma_convert_iovs() is a latent bug: the transport never calls xprt_write_space() when more pages become available. -ENOBUFS will trigger the correct "delay briefly and call again" logic. Fixes: 7a89f9c626e3 ("xprtrdma: Honor ->send_request API contract") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a8f688ec437dc2045cc8f0c89fe877d5803850da upstream.

The use of -EAGAIN in rpcrdma_convert_iovs() is a latent bug: the
transport never calls xprt_write_space() when more pages become
available. -ENOBUFS will trigger the correct "delay briefly and call
again" logic.

Fixes: 7a89f9c626e3 ("xprtrdma: Honor ->send_request API contract")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan 2018-06-25T23:51:20+00:00 Willem de Bruijn willemb@google.com 2018-06-06T15:23:01+00:00 aba9ac38845ce702fc5a579b44abef1f0006600d [ Upstream commit fd3a88625844907151737fc3b4201676effa6d27 ] Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr to communicate packet metadata to userspace. For skbuffs with vlan, the first two return the packet as it may have existed on the wire, inserting the VLAN tag in the user buffer. Then virtio_net_hdr.csum_start needs to be adjusted by VLAN_HLEN bytes. Commit f09e2249c4f5 ("macvtap: restore vlan header on user read") added this feature to macvtap. Commit 3ce9b20f1971 ("macvtap: Fix csum_start when VLAN tags are present") then fixed up csum_start. Virtio, packet and uml do not insert the vlan header in the user buffer. When introducing virtio_net_hdr_from_skb to deduplicate filling in the virtio_net_hdr, the variant from macvtap which adds VLAN_HLEN was applied uniformly, breaking csum offset for packets with vlan on virtio and packet. Make insertion of VLAN_HLEN optional. Convert the callers to pass it when needed. Fixes: e858fae2b0b8f4 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion") Fixes: 1276f24eeef2 ("packet: use common code for virtio_net_hdr and skb GSO conversion") Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit fd3a88625844907151737fc3b4201676effa6d27 ]

Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr
to communicate packet metadata to userspace.

For skbuffs with vlan, the first two return the packet as it may have
existed on the wire, inserting the VLAN tag in the user buffer.  Then
virtio_net_hdr.csum_start needs to be adjusted by VLAN_HLEN bytes.

Commit f09e2249c4f5 ("macvtap: restore vlan header on user read")
added this feature to macvtap. Commit 3ce9b20f1971 ("macvtap: Fix
csum_start when VLAN tags are present") then fixed up csum_start.

Virtio, packet and uml do not insert the vlan header in the user
buffer.

When introducing virtio_net_hdr_from_skb to deduplicate filling in
the virtio_net_hdr, the variant from macvtap which adds VLAN_HLEN was
applied uniformly, breaking csum offset for packets with vlan on
virtio and packet.

Make insertion of VLAN_HLEN optional. Convert the callers to pass it
when needed.

Fixes: e858fae2b0b8f4 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion")
Fixes: 1276f24eeef2 ("packet: use common code for virtio_net_hdr and skb GSO conversion")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
udp: fix rx queue len reported by diag and proc interface 2018-06-25T23:51:19+00:00 Paolo Abeni pabeni@redhat.com 2018-06-08T09:35:40+00:00 e8b9a16954b5a87f8f8ac96b309c50189f6c1026 [ Upstream commit 6c206b20092a3623184cff9470dba75d21507874 ] After commit 6b229cf77d68 ("udp: add batching to udp_rmem_release()") the sk_rmem_alloc field does not measure exactly anymore the receive queue length, because we batch the rmem release. The issue is really apparent only after commit 0d4a6608f68c ("udp: do rmem bulk free even if the rx sk queue is empty"): the user space can easily check for an empty socket with not-0 queue length reported by the 'ss' tool or the procfs interface. We need to use a custom UDP helper to report the correct queue length, taking into account the forward allocation deficit. Reported-by: trevor.francis@46labs.com Fixes: 6b229cf77d68 ("UDP: add batching to udp_rmem_release()") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 6c206b20092a3623184cff9470dba75d21507874 ]

After commit 6b229cf77d68 ("udp: add batching to udp_rmem_release()")
the sk_rmem_alloc field does not measure exactly anymore the
receive queue length, because we batch the rmem release. The issue
is really apparent only after commit 0d4a6608f68c ("udp: do rmem bulk
free even if the rx sk queue is empty"): the user space can easily
check for an empty socket with not-0 queue length reported by the 'ss'
tool or the procfs interface.

We need to use a custom UDP helper to report the correct queue length,
taking into account the forward allocation deficit.

Reported-by: trevor.francis@46labs.com
Fixes: 6b229cf77d68 ("UDP: add batching to udp_rmem_release()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
socket: close race condition between sock_close() and sockfs_setattr() 2018-06-25T23:51:19+00:00 Cong Wang xiyou.wangcong@gmail.com 2018-06-07T20:39:49+00:00 be3bb23cc0e4943922db828b923648af7a9f2dc3 [ Upstream commit 6d8c50dcb029872b298eea68cc6209c866fd3e14 ] fchownat() doesn't even hold refcnt of fd until it figures out fd is really needed (otherwise is ignored) and releases it after it resolves the path. This means sock_close() could race with sockfs_setattr(), which leads to a NULL pointer dereference since typically we set sock->sk to NULL in ->release(). As pointed out by Al, this is unique to sockfs. So we can fix this in socket layer by acquiring inode_lock in sock_close() and checking against NULL in sockfs_setattr(). sock_release() is called in many places, only the sock_close() path matters here. And fortunately, this should not affect normal sock_close() as it is only called when the last fd refcnt is gone. It only affects sock_close() with a parallel sockfs_setattr() in progress, which is not common. Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.") Reported-by: shankarapailoor <shankarapailoor@gmail.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Lorenzo Colitti <lorenzo@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 6d8c50dcb029872b298eea68cc6209c866fd3e14 ]

fchownat() doesn't even hold refcnt of fd until it figures out
fd is really needed (otherwise is ignored) and releases it after
it resolves the path. This means sock_close() could race with
sockfs_setattr(), which leads to a NULL pointer dereference
since typically we set sock->sk to NULL in ->release().

As pointed out by Al, this is unique to sockfs. So we can fix this
in socket layer by acquiring inode_lock in sock_close() and
checking against NULL in sockfs_setattr().

sock_release() is called in many places, only the sock_close()
path matters here. And fortunately, this should not affect normal
sock_close() as it is only called when the last fd refcnt is gone.
It only affects sock_close() with a parallel sockfs_setattr() in
progress, which is not common.

Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.")
Reported-by: shankarapailoor <shankarapailoor@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tls: fix waitall behavior in tls_sw_recvmsg 2018-06-25T23:51:18+00:00 Daniel Borkmann daniel@iogearbox.net 2018-06-15T01:07:46+00:00 6196f30e84ca9f8ad53cd15aaef163b453ed7d20 [ Upstream commit 06030dbaf3b6c5801dcdb7fe4fbab3b91c8da84a ] Current behavior in tls_sw_recvmsg() is to wait for incoming tls messages and copy up to exactly len bytes of data that the user provided. This is problematic in the sense that i) if no packet is currently queued in strparser we keep waiting until one has been processed and pushed into tls receive layer for tls_wait_data() to wake up and push the decrypted bits to user space. Given after tls decryption, we're back at streaming data, use sock_rcvlowat() hint from tcp socket instead. Retain current behavior with MSG_WAITALL flag and otherwise use the hint target for breaking the loop and returning to application. This is done if currently no ctx->recv_pkt is ready, otherwise continue to process it from our strparser backlog. Fixes: c46234ebb4d1 ("tls: RX path for ktls") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 06030dbaf3b6c5801dcdb7fe4fbab3b91c8da84a ]

Current behavior in tls_sw_recvmsg() is to wait for incoming tls
messages and copy up to exactly len bytes of data that the user
provided. This is problematic in the sense that i) if no packet
is currently queued in strparser we keep waiting until one has been
processed and pushed into tls receive layer for tls_wait_data() to
wake up and push the decrypted bits to user space. Given after
tls decryption, we're back at streaming data, use sock_rcvlowat()
hint from tcp socket instead. Retain current behavior with MSG_WAITALL
flag and otherwise use the hint target for breaking the loop and
returning to application. This is done if currently no ctx->recv_pkt
is ready, otherwise continue to process it from our strparser
backlog.

Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tls: fix use-after-free in tls_push_record 2018-06-25T23:51:18+00:00 Daniel Borkmann daniel@iogearbox.net 2018-06-15T01:07:45+00:00 7fd98de479ea75144d71862d67eb597c868bf453 [ Upstream commit a447da7d00410278c90d3576782a43f8b675d7be ] syzkaller managed to trigger a use-after-free in tls like the following: BUG: KASAN: use-after-free in tls_push_record.constprop.15+0x6a2/0x810 [tls] Write of size 1 at addr ffff88037aa08000 by task a.out/2317 CPU: 3 PID: 2317 Comm: a.out Not tainted 4.17.0+ #144 Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET47W (1.21 ) 11/28/2016 Call Trace: dump_stack+0x71/0xab print_address_description+0x6a/0x280 kasan_report+0x258/0x380 ? tls_push_record.constprop.15+0x6a2/0x810 [tls] tls_push_record.constprop.15+0x6a2/0x810 [tls] tls_sw_push_pending_record+0x2e/0x40 [tls] tls_sk_proto_close+0x3fe/0x710 [tls] ? tcp_check_oom+0x4c0/0x4c0 ? tls_write_space+0x260/0x260 [tls] ? kmem_cache_free+0x88/0x1f0 inet_release+0xd6/0x1b0 __sock_release+0xc0/0x240 sock_close+0x11/0x20 __fput+0x22d/0x660 task_work_run+0x114/0x1a0 do_exit+0x71a/0x2780 ? mm_update_next_owner+0x650/0x650 ? handle_mm_fault+0x2f5/0x5f0 ? __do_page_fault+0x44f/0xa50 ? mm_fault_error+0x2d0/0x2d0 do_group_exit+0xde/0x300 __x64_sys_exit_group+0x3a/0x50 do_syscall_64+0x9a/0x300 ? page_fault+0x8/0x30 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This happened through fault injection where aead_req allocation in tls_do_encryption() eventually failed and we returned -ENOMEM from the function. Turns out that the use-after-free is triggered from tls_sw_sendmsg() in the second tls_push_record(). The error then triggers a jump to waiting for memory in sk_stream_wait_memory() resp. returning immediately in case of MSG_DONTWAIT. What follows is the trim_both_sgl(sk, orig_size), which drops elements from the sg list added via tls_sw_sendmsg(). Now the use-after-free gets triggered when the socket is being closed, where tls_sk_proto_close() callback is invoked. The tls_complete_pending_work() will figure that there's a pending closed tls record to be flushed and thus calls into the tls_push_pending_closed_record() from there. ctx->push_pending_record() is called from the latter, which is the tls_sw_push_pending_record() from sw path. This again calls into tls_push_record(). And here the tls_fill_prepend() will panic since the buffer address has been freed earlier via trim_both_sgl(). One way to fix it is to move the aead request allocation out of tls_do_encryption() early into tls_push_record(). This means we don't prep the tls header and advance state to the TLS_PENDING_CLOSED_RECORD before allocation which could potentially fail happened. That fixes the issue on my side. Fixes: 3c4d7559159b ("tls: kernel TLS support") Reported-by: syzbot+5c74af81c547738e1684@syzkaller.appspotmail.com Reported-by: syzbot+709f2810a6a05f11d4d3@syzkaller.appspotmail.com Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Dave Watson <davejwatson@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit a447da7d00410278c90d3576782a43f8b675d7be ]

syzkaller managed to trigger a use-after-free in tls like the
following:

  BUG: KASAN: use-after-free in tls_push_record.constprop.15+0x6a2/0x810 [tls]
  Write of size 1 at addr ffff88037aa08000 by task a.out/2317

  CPU: 3 PID: 2317 Comm: a.out Not tainted 4.17.0+ #144
  Hardware name: LENOVO 20FBCTO1WW/20FBCTO1WW, BIOS N1FET47W (1.21 ) 11/28/2016
  Call Trace:
   dump_stack+0x71/0xab
   print_address_description+0x6a/0x280
   kasan_report+0x258/0x380
   ? tls_push_record.constprop.15+0x6a2/0x810 [tls]
   tls_push_record.constprop.15+0x6a2/0x810 [tls]
   tls_sw_push_pending_record+0x2e/0x40 [tls]
   tls_sk_proto_close+0x3fe/0x710 [tls]
   ? tcp_check_oom+0x4c0/0x4c0
   ? tls_write_space+0x260/0x260 [tls]
   ? kmem_cache_free+0x88/0x1f0
   inet_release+0xd6/0x1b0
   __sock_release+0xc0/0x240
   sock_close+0x11/0x20
   __fput+0x22d/0x660
   task_work_run+0x114/0x1a0
   do_exit+0x71a/0x2780
   ? mm_update_next_owner+0x650/0x650
   ? handle_mm_fault+0x2f5/0x5f0
   ? __do_page_fault+0x44f/0xa50
   ? mm_fault_error+0x2d0/0x2d0
   do_group_exit+0xde/0x300
   __x64_sys_exit_group+0x3a/0x50
   do_syscall_64+0x9a/0x300
   ? page_fault+0x8/0x30
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happened through fault injection where aead_req allocation in
tls_do_encryption() eventually failed and we returned -ENOMEM from
the function. Turns out that the use-after-free is triggered from
tls_sw_sendmsg() in the second tls_push_record(). The error then
triggers a jump to waiting for memory in sk_stream_wait_memory()
resp. returning immediately in case of MSG_DONTWAIT. What follows is
the trim_both_sgl(sk, orig_size), which drops elements from the sg
list added via tls_sw_sendmsg(). Now the use-after-free gets triggered
when the socket is being closed, where tls_sk_proto_close() callback
is invoked. The tls_complete_pending_work() will figure that there's
a pending closed tls record to be flushed and thus calls into the
tls_push_pending_closed_record() from there. ctx->push_pending_record()
is called from the latter, which is the tls_sw_push_pending_record()
from sw path. This again calls into tls_push_record(). And here the
tls_fill_prepend() will panic since the buffer address has been freed
earlier via trim_both_sgl(). One way to fix it is to move the aead
request allocation out of tls_do_encryption() early into tls_push_record().
This means we don't prep the tls header and advance state to the
TLS_PENDING_CLOSED_RECORD before allocation which could potentially
fail happened. That fixes the issue on my side.

Fixes: 3c4d7559159b ("tls: kernel TLS support")
Reported-by: syzbot+5c74af81c547738e1684@syzkaller.appspotmail.com
Reported-by: syzbot+709f2810a6a05f11d4d3@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>