OpenCloudOS-Kernel/include
Hou Tao 3af43ba4c6 bpf: Pass map file to .map_update_batch directly
Currently bpf_map_do_batch() first invokes fdget(batch.map_fd) to get
the target map file, then it invokes generic_map_update_batch() to do
batch update. generic_map_update_batch() will get the target map file
by using fdget(batch.map_fd) again and pass it to bpf_map_update_value().

The problem is map file returned by the second fdget() may be NULL or a
totally different file compared by map file in bpf_map_do_batch(). The
reason is that the first fdget() only guarantees the liveness of struct
file instead of file descriptor and the file description may be released
by concurrent close() through pick_file().

It doesn't incur any problem as for now, because maps with batch update
support don't use map file in .map_fd_get_ptr() ops. But it is better to
fix the potential access of an invalid map file.

Using __bpf_map_get() again in generic_map_update_batch() can not fix
the problem, because batch.map_fd may be closed and reopened, and the
returned map file may be different with map file got in
bpf_map_do_batch(), so just passing the map file directly to
.map_update_batch() in bpf_map_do_batch().

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221116075059.1551277-1-houtao@huaweicloud.com
2022-11-17 17:12:35 +01:00
..
acpi ACPI: APEI: Fix integer overflow in ghes_estatus_pool_init() 2022-10-13 20:40:09 +02:00
asm-generic asm-generic: compat: fix compat_arg_u64() and compat_arg_u64_dual() 2022-11-01 10:20:11 +11:00
clocksource
crypto
drm Merge drm/drm-fixes into drm-misc-fixes 2022-10-20 09:09:00 +02:00
dt-bindings These are the pin control changes for the v6.1 kernel cycle: 2022-10-11 10:59:59 -07:00
keys
kunit kunit: declare kunit_assert structs as const 2022-10-07 10:19:18 -06:00
kvm
linux bpf: Pass map file to .map_update_batch directly 2022-11-17 17:12:35 +01:00
math-emu
media media fixes for v6.1-rc2 2022-10-22 15:30:15 -07:00
memory
misc
net net: flow_offload: add support for ARP frame matching 2022-11-14 11:24:16 +00:00
pcmcia
ras
rdma
rv
scsi SCSI misc on 20221007 2022-10-07 12:33:18 -07:00
soc RISC-V Patches for the 6.1 Merge Window, Part 2 2022-10-14 11:21:11 -07:00
sound ASoC: Fixes for v6.1 2022-10-27 08:26:32 +02:00
target
trace rxrpc: Fix congestion management 2022-11-08 16:42:28 +00:00
uapi bpf: Expand map key argument of bpf_redirect_map to u64 2022-11-15 09:00:27 -08:00
ufs SCSI misc on 20221007 2022-10-07 12:33:18 -07:00
vdso
video
xen xen/virtio: enable grant based virtio on x86 2022-10-10 14:31:26 +02:00