linux/include
John Fastabend 4da6a196f9 bpf: Sockmap/tls, during free we may call tcp_bpf_unhash() in loop
When a sockmap is free'd and a socket in the map is enabled with tls
we tear down the bpf context on the socket, the psock struct and state,
and then call tcp_update_ulp(). The tcp_update_ulp() call is to inform
the tls stack it needs to update its saved sock ops so that when the tls
socket is later destroyed it doesn't try to call the now destroyed psock
hooks.

This is about keeping stacked ULPs in good shape so they always have
the right set of stacked ops.

However, recently unhash() hook was removed from TLS side. But, the
sockmap/bpf side is not doing any extra work to update the unhash op
when is torn down instead expecting TLS side to manage it. So both
TLS and sockmap believe the other side is managing the op and instead
no one updates the hook so it continues to point at tcp_bpf_unhash().
When unhash hook is called we call tcp_bpf_unhash() which detects the
psock has already been destroyed and calls sk->sk_prot_unhash() which
calls tcp_bpf_unhash() yet again and so on looping and hanging the core.

To fix have sockmap tear down logic fixup the stale pointer.

Fixes: 5d92e631b8 ("net/tls: partially revert fix transition through disconnect with close")
Reported-by: syzbot+83979935eb6304f8cd46@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20200111061206.8028-2-john.fastabend@gmail.com
2020-01-15 23:26:13 +01:00
..
acpi Merge branches 'acpi-utils', 'acpi-platform', 'acpi-video' and 'acpi-doc' 2019-11-26 10:30:49 +01:00
asm-generic powerpc updates for 5.5 #2 2019-12-06 13:36:31 -08:00
clocksource x86/hyperv: Initialize clockevents earlier in CPU onlining 2019-11-15 10:33:49 +01:00
crypto crypto: ablkcipher - remove deprecated and unused ablkcipher support 2019-11-17 09:02:49 +08:00
drm mm + drm coherent memory support for vmwgfx 2019-11-30 09:38:11 -08:00
dt-bindings ARM: Device-tree updates 2019-12-05 12:09:47 -08:00
keys powerpc updates for 5.5 2019-11-30 14:35:43 -08:00
kunit
kvm
linux bpf: Sockmap/tls, during free we may call tcp_bpf_unhash() in loop 2020-01-15 23:26:13 +01:00
math-emu
media drm main pull for 5.5-rc1 2019-11-27 17:45:48 -08:00
misc
net net/sched: add delete_empty() to filters and use it in cls_flower 2019-12-30 20:35:19 -08:00
pcmcia
ras
rdma IB/core: Introduce rdma_user_mmap_entry_insert_range() API 2019-12-12 16:55:36 -05:00
scsi scsi: target: iscsi: Wait for all commands to finish before freeing a session 2019-11-19 21:37:35 -05:00
soc drm msm + fixes for 5.5-rc1 2019-12-06 10:28:09 -08:00
sound ASoC: Fixes for v5.5 2019-12-17 14:18:32 +01:00
target
trace This is a relatively quiet cycle for nfsd, mainly various bugfixes. 2019-12-07 16:56:00 -08:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-22 09:54:33 -08:00
vdso
video
xen xen/interface: re-define FRONT/BACK_RING_ATTACH() 2019-12-20 13:44:42 +01:00