linux.git/net/bpf, branch v6.6.83

bpf, test_run: Fix use-after-free issue in eth_skb_pkt_type()

2025-02-27T12:10:50+00:00

[ Upstream commit 6b3d638ca897e099fa99bd6d02189d3176f80a47 ]

KMSAN reported a use-after-free issue in eth_skb_pkt_type()[1]. The
cause of the issue was that eth_skb_pkt_type() accessed skb's data
that didn't contain an Ethernet header. This occurs when
bpf_prog_test_run_xdp() passes an invalid value as the user_data
argument to bpf_test_init().

Fix this by returning an error when user_data is less than ETH_HLEN in
bpf_test_init(). Additionally, remove the check for "if (user_size >
size)" as it is unnecessary.

[1]
BUG: KMSAN: use-after-free in eth_skb_pkt_type include/linux/etherdevice.h:627 [inline]
BUG: KMSAN: use-after-free in eth_type_trans+0x4ee/0x980 net/ethernet/eth.c:165
 eth_skb_pkt_type include/linux/etherdevice.h:627 [inline]
 eth_type_trans+0x4ee/0x980 net/ethernet/eth.c:165
 __xdp_build_skb_from_frame+0x5a8/0xa50 net/core/xdp.c:635
 xdp_recv_frames net/bpf/test_run.c:272 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0x2954/0x3330 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0x148e/0x1b10 net/bpf/test_run.c:1318
 bpf_prog_test_run+0x5b7/0xa30 kernel/bpf/syscall.c:4371
 __sys_bpf+0x6a6/0xe20 kernel/bpf/syscall.c:5777
 __do_sys_bpf kernel/bpf/syscall.c:5866 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5864 [inline]
 __x64_sys_bpf+0xa4/0xf0 kernel/bpf/syscall.c:5864
 x64_sys_call+0x2ea0/0x3d90 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 free_pages_prepare mm/page_alloc.c:1056 [inline]
 free_unref_page+0x156/0x1320 mm/page_alloc.c:2657
 __free_pages+0xa3/0x1b0 mm/page_alloc.c:4838
 bpf_ringbuf_free kernel/bpf/ringbuf.c:226 [inline]
 ringbuf_map_free+0xff/0x1e0 kernel/bpf/ringbuf.c:235
 bpf_map_free kernel/bpf/syscall.c:838 [inline]
 bpf_map_free_deferred+0x17c/0x310 kernel/bpf/syscall.c:862
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa2b/0x1b60 kernel/workqueue.c:3310
 worker_thread+0xedf/0x1550 kernel/workqueue.c:3391
 kthread+0x535/0x6b0 kernel/kthread.c:389
 ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

CPU: 1 UID: 0 PID: 17276 Comm: syz.1.16450 Not tainted 6.12.0-05490-g9bb88c659673 #8
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014

Fixes: be3d72a2896c ("bpf: move user_size out of bpf_test_init")
Reported-by: syzkaller 
Suggested-by: Martin KaFai Lau 
Signed-off-by: Shigeru Yoshida 
Signed-off-by: Martin KaFai Lau 
Acked-by: Stanislav Fomichev 
Acked-by: Daniel Borkmann 
Link: https://patch.msgid.link/20250121150643.671650-1-syoshida@redhat.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf, test_run: Fix LIVE_FRAME frame update after a page has been recycled

2024-11-08T15:28:19+00:00

[ Upstream commit c40dd8c4732551605712985bc5b7045094c6458d ]

The test_run code detects whether a page has been modified and
re-initialises the xdp_frame structure if it has, using
xdp_update_frame_from_buff(). However, xdp_update_frame_from_buff()
doesn't touch frame->mem, so that wasn't correctly re-initialised, which
led to the pages from page_pool not being returned correctly. Syzbot
noticed this as a memory leak.

Fix this by also copying the frame->mem structure when re-initialising
the frame, like we do on initialisation of a new page from page_pool.

Fixes: e5995bc7e2ba ("bpf, test_run: fix crashes due to XDP frame overwriting/corruption")
Fixes: b530e9e1063e ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Reported-by: syzbot+d121e098da06af416d23@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Daniel Borkmann 
Tested-by: syzbot+d121e098da06af416d23@syzkaller.appspotmail.com
Reviewed-by: Alexander Lobakin 
Acked-by: Stanislav Fomichev 
Link: https://lore.kernel.org/bpf/20241030-test-run-mem-fix-v1-1-41e88e8cae43@redhat.com
Signed-off-by: Sasha Levin

bpf: Set run context for rawtp test_run callback

2024-06-21T12:38:16+00:00

[ Upstream commit d0d1df8ba18abc57f28fb3bc053b2bf319367f2c ]

syzbot reported crash when rawtp program executed through the
test_run interface calls bpf_get_attach_cookie helper or any
other helper that touches task->bpf_ctx pointer.

Setting the run context (task->bpf_ctx pointer) for test_run
callback.

Fixes: 7adfc6c9b315 ("bpf: Add bpf_get_attach_cookie() BPF helper to access bpf_cookie value")
Reported-by: syzbot+3ab78ff125b7979e45f9@syzkaller.appspotmail.com
Signed-off-by: Jiri Olsa 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Closes: https://syzkaller.appspot.com/bug?extid=3ab78ff125b7979e45f9
Link: https://lore.kernel.org/bpf/20240604150024.359247-1-jolsa@kernel.org
Signed-off-by: Sasha Levin

bpf: Fix a few selftest failures due to llvm18 change

2024-02-05T20:14:20+00:00

[ Upstream commit b16904fd9f01b580db357ef2b1cc9e86d89576c2 ]

With latest upstream llvm18, the following test cases failed:

  $ ./test_progs -j
  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #77      fentry_fexit:FAIL
  #78/1    fentry_test/fentry:FAIL
  #78      fentry_test:FAIL
  #82/1    fexit_test/fexit:FAIL
  #82      fexit_test:FAIL
  #112/1   kprobe_multi_test/skel_api:FAIL
  #112/2   kprobe_multi_test/link_api_addrs:FAIL
  [...]
  #112     kprobe_multi_test:FAIL
  #356/17  test_global_funcs/global_func17:FAIL
  #356     test_global_funcs:FAIL

Further analysis shows llvm upstream patch [1] is responsible for the above
failures. For example, for function bpf_fentry_test7() in net/bpf/test_run.c,
without [1], the asm code is:

  0000000000000400 :
     400: f3 0f 1e fa                   endbr64
     404: e8 00 00 00 00                callq   0x409 
     409: 48 89 f8                      movq    %rdi, %rax
     40c: c3                            retq
     40d: 0f 1f 00                      nopl    (%rax)

... and with [1], the asm code is:

  0000000000005d20 :
    5d20: e8 00 00 00 00                callq   0x5d25 
    5d25: c3                            retq

... and  is called instead of 
and this caused test failures for #13/#77 etc. except #356.

For test case #356/17, with [1] (progs/test_global_func17.c)), the main prog
looks like:

  0000000000000000 :
       0:       b4 00 00 00 2a 00 00 00 w0 = 0x2a
       1:       95 00 00 00 00 00 00 00 exit

... which passed verification while the test itself expects a verification
failure.

Let us add 'barrier_var' style asm code in both places to prevent function
specialization which caused selftests failure.

  [1] https://github.com/llvm/llvm-project/pull/72903

Signed-off-by: Yonghong Song 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20231127050342.1945270-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin

bpf: Prevent inlining of bpf_fentry_test7()

2023-08-30T06:36:17+00:00

With latest clang18, I hit test_progs failures for the following test:

  #13/2    bpf_cookie/multi_kprobe_link_api:FAIL
  #13/3    bpf_cookie/multi_kprobe_attach_api:FAIL
  #13      bpf_cookie:FAIL
  #75      fentry_fexit:FAIL
  #76/1    fentry_test/fentry:FAIL
  #76      fentry_test:FAIL
  #80/1    fexit_test/fexit:FAIL
  #80      fexit_test:FAIL
  #110/1   kprobe_multi_test/skel_api:FAIL
  #110/2   kprobe_multi_test/link_api_addrs:FAIL
  #110/3   kprobe_multi_test/link_api_syms:FAIL
  #110/4   kprobe_multi_test/attach_api_pattern:FAIL
  #110/5   kprobe_multi_test/attach_api_addrs:FAIL
  #110/6   kprobe_multi_test/attach_api_syms:FAIL
  #110     kprobe_multi_test:FAIL

For example, for #13/2, the error messages are:

  [...]
  kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
  [...]
  kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1

clang17 does not have this issue.

Further investigation shows that kernel func bpf_fentry_test7(), used in
the above tests, is inlined by the compiler although it is marked as
noinline.

  int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
  {
        return (long)arg;
  }

It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.

Signed-off-by: Yonghong Song 
Signed-off-by: Daniel Borkmann 
Tested-by: Eduard Zingerman 
Link: https://lore.kernel.org/bpf/20230826200843.2210074-1-yonghong.song@linux.dev

page_pool: split types and declarations from page_pool.h

2023-08-07T20:05:19+00:00

Split types and pure function declarations from page_pool.h
and add them in page_page/types.h, so that C sources can
include page_pool.h and headers should generally only include
page_pool/types.h as suggested by jakub.
Rename page_pool.h to page_pool/helpers.h to have both in
one place.

Signed-off-by: Yunsheng Lin 
Suggested-by: Jakub Kicinski 
Signed-off-by: Alexander Lobakin 
Reviewed-by: Alexander Duyck 
Link: https://lore.kernel.org/r/20230804180529.2483231-2-aleksander.lobakin@intel.com
[Jakub: change microsoft/mana, fix kdoc paths in Documentation]
Signed-off-by: Jakub Kicinski

net: move struct netdev_rx_queue out of netdevice.h

2023-08-03T15:38:07+00:00

struct netdev_rx_queue is touched in only a few places
and having it defined in netdevice.h brings in the dependency
on xdp.h, because struct xdp_rxq_info gets embedded in
struct netdev_rx_queue.

In prep for removal of xdp.h from netdevice.h move all
the netdev_rx_queue stuff to a new header.

We could technically break the new header up to avoid
the sysfs.h include but it's so rarely included it
doesn't seem to be worth it at this point.

Reviewed-by: Amritha Nambiar 
Signed-off-by: Jakub Kicinski 
Acked-by: Jesper Dangaard Brouer 
Link: https://lore.kernel.org/r/20230803010230.1755386-3-kuba@kernel.org
Signed-off-by: Martin KaFai Lau

selftests/bpf: add testcase for TRACING with 6+ arguments

2023-07-13T23:04:56+00:00

Add fentry_many_args.c and fexit_many_args.c to test the fentry/fexit
with 7/11 arguments. As this feature is not supported by arm64 yet, we
disable these testcases for arm64 in DENYLIST.aarch64. We can combine
them with fentry_test.c/fexit_test.c when arm64 is supported too.

Correspondingly, add bpf_testmod_fentry_test7() and
bpf_testmod_fentry_test11() to bpf_testmod.c

Meanwhile, add bpf_modify_return_test2() to test_run.c to test the
MODIFY_RETURN with 7 arguments.

Add bpf_testmod_test_struct_arg_7/bpf_testmod_test_struct_arg_7 in
bpf_testmod.c to test the struct in the arguments.

And the testcases passed on x86_64:

./test_progs -t fexit
Summary: 5/14 PASSED, 0 SKIPPED, 0 FAILED

./test_progs -t fentry
Summary: 3/2 PASSED, 0 SKIPPED, 0 FAILED

./test_progs -t modify_return
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

./test_progs -t tracing_struct
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Menglong Dong 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/r/20230713040738.1789742-4-imagedong@tencent.com
Signed-off-by: Alexei Starovoitov

selftests/bpf: Add test to exercise typedef walking

2023-06-30T08:36:08+00:00

Add new bpf_fentry_test_sinfo with skb_shared_info argument and try to
access frags.

Signed-off-by: Stanislav Fomichev 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20230626212522.2414485-2-sdf@google.com

bpf: Move kernel test kfuncs to bpf_testmod

2023-05-17T05:09:24+00:00

Moving kernel test kfuncs into bpf_testmod kernel module, and adding
necessary init calls and BTF IDs records.

We need to keep following structs in kernel:
  struct prog_test_ref_kfunc
  struct prog_test_member (embedded in prog_test_ref_kfunc)

The reason is because they need to be marked as rcu safe (check test
prog mark_ref_as_untrusted_or_null) and such objects are being required
to be defined only in kernel at the moment (see rcu_safe_kptr check
in kernel).

We need to keep also dtor functions for both objects in kernel:
  bpf_kfunc_call_test_release
  bpf_kfunc_call_memb_release

We also keep the copy of these struct in bpf_testmod_kfunc.h, because
other test functions use them. This is unfortunate, but this is just
temporary solution until we are able to these structs them to bpf_testmod
completely.

As suggested by David adding bpf_testmod.ko make dependency for
bpf programs, so they are rebuilt if we change the bpf_testmod.ko
module.

Also adding missing __bpf_kfunc to bpf_kfunc_call_test4 functions.

Signed-off-by: Jiri Olsa 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20230515133756.1658301-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov