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Menglong Dong 8f49e1694c bpf: Fix probe read error in ___bpf_prog_run()
[ Upstream commit caff1fa4118cec4dfd4336521ebd22a6408a1e3e ]

I think there is something wrong with BPF_PROBE_MEM in ___bpf_prog_run()
in big-endian machine. Let's make a test and see what will happen if we
want to load a 'u16' with BPF_PROBE_MEM.

Let's make the src value '0x0001', the value of dest register will become
0x0001000000000000, as the value will be loaded to the first 2 byte of
DST with following code:

  bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off));

Obviously, the value in DST is not correct. In fact, we can compare
BPF_PROBE_MEM with LDX_MEM_H:

  DST = *(SIZE *)(unsigned long) (SRC + insn->off);

If the memory load is done by LDX_MEM_H, the value in DST will be 0x1 now.

And I think this error results in the test case 'test_bpf_sk_storage_map'
failing:

  test_bpf_sk_storage_map:PASS:bpf_iter_bpf_sk_storage_map__open_and_load 0 nsec
  test_bpf_sk_storage_map:PASS:socket 0 nsec
  test_bpf_sk_storage_map:PASS:map_update 0 nsec
  test_bpf_sk_storage_map:PASS:socket 0 nsec
  test_bpf_sk_storage_map:PASS:map_update 0 nsec
  test_bpf_sk_storage_map:PASS:socket 0 nsec
  test_bpf_sk_storage_map:PASS:map_update 0 nsec
  test_bpf_sk_storage_map:PASS:attach_iter 0 nsec
  test_bpf_sk_storage_map:PASS:create_iter 0 nsec
  test_bpf_sk_storage_map:PASS:read 0 nsec
  test_bpf_sk_storage_map:FAIL:ipv6_sk_count got 0 expected 3
  $10/26 bpf_iter/bpf_sk_storage_map:FAIL

The code of the test case is simply, it will load sk->sk_family to the
register with BPF_PROBE_MEM and check if it is AF_INET6. With this patch,
now the test case 'bpf_iter' can pass:

  $10  bpf_iter:OK

Fixes: 2a02759ef5 ("bpf: Add support for BTF pointers to interpreter")
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20220524021228.533216-1-imagedong@tencent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:32:35 +02:00
arch s390/crypto: fix scatterwalk_unmap() callers in AES-GCM 2022-06-14 18:32:35 +02:00
block block: fix bio_clone_blkg_association() to associate with proper blkcg_gq 2022-06-09 10:21:31 +02:00
certs certs: Trigger creation of RSA module signing key if it's not an RSA key 2021-09-15 09:50:29 +02:00
crypto crypto: cryptd - Protect per-CPU resource by disabling BH. 2022-06-09 10:21:17 +02:00
Documentation dt-bindings: gpio: altera: correct interrupt-cells 2022-06-09 10:21:29 +02:00
drivers ubi: ubi_create_volume: Fix use-after-free when volume creation failed 2022-06-14 18:32:35 +02:00
fs jffs2: fix memory leak in jffs2_do_fill_super 2022-06-14 18:32:35 +02:00
include net: sched: fixed barrier to prevent skbuff sticking in qdisc backlog 2022-06-14 18:32:35 +02:00
init Kconfig: Add option for asm goto w/ tied outputs to workaround clang-13 bug 2022-06-09 10:21:25 +02:00
ipc ipc/mqueue: use get_tree_nodev() in mqueue_get_tree() 2022-06-09 10:21:17 +02:00
kernel bpf: Fix probe read error in ___bpf_prog_run() 2022-06-14 18:32:35 +02:00
lib lib/crypto: add prompts back to crypto libraries 2022-06-06 08:42:42 +02:00
LICENSES
mm hugetlb: fix huge_pmd_unshare address update 2022-06-09 10:21:27 +02:00
net mac80211: upgrade passive scan to active scan on DFS channels after beacon rx 2022-06-09 10:21:26 +02:00
samples samples/bpf, xdpsock: Fix race when running for fix duration of time 2022-04-08 14:40:21 +02:00
scripts modpost: fix removing numeric suffixes 2022-06-14 18:32:35 +02:00
security ima: remove the IMA_TEMPLATE Kconfig option 2022-06-09 10:21:25 +02:00
sound ASoC: fsl_sai: Fix FSL_SAI_xDR/xFR definition 2022-06-14 18:32:34 +02:00
tools kseltest/cgroup: Make test_stress.sh work if run interactively 2022-06-09 10:21:30 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:25:48 +01:00
virt KVM: Prevent module exit until all VMs are freed 2022-04-08 14:40:38 +02:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS MAINTAINERS: add git tree for random.c 2022-05-30 09:33:24 +02:00
Makefile Linux 5.10.121 2022-06-09 10:21:31 +02:00
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