[ Upstream commit a447da7d00 ]
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: 3c4d755915 ("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 cf6d43ef66 ]
During setsockopt(SOL_TCP, TLS_TX), if initialization of the software
context fails in tls_set_sw_offload(), we leak sw_ctx. We also don't
reassign ctx->priv_ctx to NULL, so we can't even do another attempt to
set it up on the same socket, as it will fail with -EEXIST.
Fixes: 3c4d755915 ('tls: kernel TLS support')
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 30be8f8dba ]
sendfile() calls can hang endless with using Kernel TLS if a socket error occurs.
Socket error codes must be inverted by Kernel TLS before returning because
they are stored with positive sign. If returned non-inverted they are
interpreted as number of bytes sent, causing endless looping of the
splice mechanic behind sendfile().
Signed-off-by: Robert Hering <r.hering@avm.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the needlessly global function tls_sw_free_resources static to fix
a gcc/sparse warning.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Software implementation of transport layer security, implemented using ULP
infrastructure. tcp proto_ops are replaced with tls equivalents of sendmsg and
sendpage.
Only symmetric crypto is done in the kernel, keys are passed by setsockopt
after the handshake is complete. All control messages are supported via CMSG
data - the actual symmetric encryption is the same, just the message type needs
to be passed separately.
For user API, please see Documentation patch.
Pieces that can be shared between hw and sw implementation
are in tls_main.c
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
