linux-stable/net/xdp
Magnus Karlsson 6436973164 xsk: Fix xsk_diag use-after-free error during socket cleanup
[ Upstream commit 3e019d8a05 ]

Fix a use-after-free error that is possible if the xsk_diag interface
is used after the socket has been unbound from the device. This can
happen either due to the socket being closed or the device
disappearing. In the early days of AF_XDP, the way we tested that a
socket was not bound to a device was to simply check if the netdevice
pointer in the xsk socket structure was NULL. Later, a better system
was introduced by having an explicit state variable in the xsk socket
struct. For example, the state of a socket that is on the way to being
closed and has been unbound from the device is XSK_UNBOUND.

The commit in the Fixes tag below deleted the old way of signalling
that a socket is unbound, setting dev to NULL. This in the belief that
all code using the old way had been exterminated. That was
unfortunately not true as the xsk diagnostics code was still using the
old way and thus does not work as intended when a socket is going
down. Fix this by introducing a test against the state variable. If
the socket is in the state XSK_UNBOUND, simply abort the diagnostic's
netlink operation.

Fixes: 18b1ab7aa7 ("xsk: Fix race at socket teardown")
Reported-by: syzbot+822d1359297e2694f873@syzkaller.appspotmail.com
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+822d1359297e2694f873@syzkaller.appspotmail.com
Tested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20230831100119.17408-1-magnus.karlsson@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-19 12:28:01 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile xsk: Introduce AF_XDP buffer allocation API 2020-05-21 17:31:26 -07:00
xdp_umem.c xsk: Add missing overflow check in xdp_umem_reg 2023-03-30 12:49:02 +02:00
xdp_umem.h xsk: Fix umem cleanup bug at socket destruct 2020-11-20 15:52:39 +01:00
xsk.c xsk: fix refcount underflow in error path 2023-08-16 18:27:27 +02:00
xsk.h xdp: Add proper __rcu annotations to redirect map entries 2021-06-24 19:41:15 +02:00
xsk_buff_pool.c xsk: Inherit need_wakeup flag for shared sockets 2022-09-22 17:16:22 +02:00
xsk_diag.c xsk: Fix xsk_diag use-after-free error during socket cleanup 2023-09-19 12:28:01 +02:00
xsk_queue.c xsk: Remove MEM_TYPE_ZERO_COPY and corresponding code 2020-05-21 17:31:27 -07:00
xsk_queue.h xsk: Fix unaligned descriptor validation 2023-05-11 23:03:21 +09:00
xskmap.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00