linux-stable.git/net/bpf, branch v6.17

bpf: Add attach_type field to bpf_link

2025-07-11T17:51:55+00:00

Attach_type will be set when a link is created by user. It is better to
record attach_type in bpf_link generically and have it available
universally for all link types. So add the attach_type field in bpf_link
and move the sleepable field to avoid unnecessary gap padding.

Signed-off-by: Tao Chen 
Signed-off-by: Andrii Nakryiko 
Acked-by: Daniel Borkmann 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/20250710032038.888700-2-chen.dylane@linux.dev

bpf: Fix an issue in bpf_prog_test_run_xdp when page size greater than 4K

2025-06-13T02:07:51+00:00

The bpf selftest xdp_adjust_tail/xdp_adjust_frags_tail_grow failed on
arm64 with 64KB page:
   xdp_adjust_tail/xdp_adjust_frags_tail_grow:FAIL

In bpf_prog_test_run_xdp(), the xdp->frame_sz is set to 4K, but later on
when constructing frags, with 64K page size, the frag data_len could
be more than 4K. This will cause problems in bpf_xdp_frags_increase_tail().

To fix the failure, the xdp->frame_sz is set to be PAGE_SIZE so kernel
can test different page size properly. With the kernel change, the user
space and bpf prog needs adjustment. Currently, the MAX_SKB_FRAGS default
value is 17, so for 4K page, the maximum packet size will be less than 68K.
To test 64K page, a bigger maximum packet size than 68K is desired. So two
different functions are implemented for subtest xdp_adjust_frags_tail_grow.
Depending on different page size, different data input/output sizes are used
to adapt with different page size.

Signed-off-by: Yonghong Song 
Link: https://lore.kernel.org/r/20250612035032.2207498-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov

selftests/bpf: Add test to access const void pointer argument in tracing program

2025-04-23T18:26:22+00:00

Adding verifier test for accessing const void pointer argument in
tracing programs.

The test program loads 1st argument of bpf_fentry_test10 function
which is const void pointer and checks that verifier allows that.

Signed-off-by: KaFai Wan 
Signed-off-by: Andrii Nakryiko 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/20250423121329.3163461-3-mannkafai@gmail.com

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

2025-01-29T16:51:51+00:00

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

Merge tag 'bpf-next-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-01-23T16:04:07+00:00

Pull bpf updates from Alexei Starovoitov:
 "A smaller than usual release cycle.

  The main changes are:

   - Prepare selftest to run with GCC-BPF backend (Ihor Solodrai)

     In addition to LLVM-BPF runs the BPF CI now runs GCC-BPF in compile
     only mode. Half of the tests are failing, since support for
     btf_decl_tag is still WIP, but this is a great milestone.

   - Convert various samples/bpf to selftests/bpf/test_progs format
     (Alexis Lothoré and Bastien Curutchet)

   - Teach verifier to recognize that array lookup with constant
     in-range index will always succeed (Daniel Xu)

   - Cleanup migrate disable scope in BPF maps (Hou Tao)

   - Fix bpf_timer destroy path in PREEMPT_RT (Hou Tao)

   - Always use bpf_mem_alloc in bpf_local_storage in PREEMPT_RT (Martin
     KaFai Lau)

   - Refactor verifier lock support (Kumar Kartikeya Dwivedi)

     This is a prerequisite for upcoming resilient spin lock.

   - Remove excessive 'may_goto +0' instructions in the verifier that
     LLVM leaves when unrolls the loops (Yonghong Song)

   - Remove unhelpful bpf_probe_write_user() warning message (Marco
     Elver)

   - Add fd_array_cnt attribute for prog_load command (Anton Protopopov)

     This is a prerequisite for upcoming support for static_branch"

* tag 'bpf-next-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (125 commits)
  selftests/bpf: Add some tests related to 'may_goto 0' insns
  bpf: Remove 'may_goto 0' instruction in opt_remove_nops()
  bpf: Allow 'may_goto 0' instruction in verifier
  selftests/bpf: Add test case for the freeing of bpf_timer
  bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT
  bpf: Free element after unlock in __htab_map_lookup_and_delete_elem()
  bpf: Bail out early in __htab_map_lookup_and_delete_elem()
  bpf: Free special fields after unlock in htab_lru_map_delete_node()
  tools: Sync if_xdp.h uapi tooling header
  libbpf: Work around kernel inconsistently stripping '.llvm.' suffix
  bpf: selftests: verifier: Add nullness elision tests
  bpf: verifier: Support eliding map lookup nullness
  bpf: verifier: Refactor helper access type tracking
  bpf: tcp: Mark bpf_load_hdr_opt() arg2 as read-write
  bpf: verifier: Add missing newline on verbose() call
  selftests/bpf: Add distilled BTF test about marking BTF_IS_EMBEDDED
  libbpf: Fix incorrect traversal end type ID when marking BTF_IS_EMBEDDED
  libbpf: Fix return zero when elf_begin failed
  selftests/bpf: Fix btf leak on new btf alloc failure in btf_distill test
  veristat: Load struct_ops programs only once
  ...

xdp: get rid of xdp_frame::mem.id

2024-12-13T02:22:52+00:00

Initially, xdp_frame::mem.id was used to search for the corresponding
&page_pool to return the page correctly.
However, after that struct page was extended to have a direct pointer
to its PP (netmem has it as well), further keeping of this field makes
no sense. xdp_return_frame_bulk() still used it to do a lookup, and
this leftover is now removed.
Remove xdp_frame::mem and replace it with ::mem_type, as only memory
type still matters and we need to know it to be able to free the frame
correctly.
As a cute side effect, we can now make every scalar field in &xdp_frame
of 4 byte width, speeding up accesses to them.

Reviewed-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexander Lobakin 
Link: https://patch.msgid.link/20241211172649.761483-3-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski

bpf: fix cgroup_skb prog test run direct packet access

2024-12-02T16:41:17+00:00

This is needed in the context of Tetragon to test cgroup_skb programs
using BPF_PROG_TEST_RUN with direct packet access.

Commit b39b5f411dcf ("bpf: add cg_skb_is_valid_access for
BPF_PROG_TYPE_CGROUP_SKB") added direct packet access for cgroup_skb
programs and following commit 2cb494a36c98 ("bpf: add tests for direct
packet access from CGROUP_SKB") added tests to the verifier to ensure
that access to skb fields was possible and also fixed
bpf_prog_test_run_skb. However, is_direct_pkt_access was never set to
true for this program type, so data pointers were not computed when
using prog_test_run, making data_end always equal to zero (data_meta is
not accessible for cgroup_skb).

Signed-off-by: Mahe Tardy 
Link: https://lore.kernel.org/r/20241125152603.375898-1-mahe.tardy@gmail.com
Signed-off-by: Alexei Starovoitov

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

2024-10-31T15:15:21+00:00

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

bpf: use type_may_be_null() helper for nullable-param check

2024-09-05T20:29:06+00:00

Commit 980ca8ceeae6 ("bpf: check bpf_dummy_struct_ops program params for
test runs") does bitwise AND between reg_type and PTR_MAYBE_NULL, which
is correct, but due to type difference the compiler complains:

  net/bpf/bpf_dummy_struct_ops.c:118:31: warning: bitwise operation between different enumeration types ('const enum bpf_reg_type' and 'enum bpf_type_flag') [-Wenum-enum-conversion]
    118 |                 if (info && (info->reg_type & PTR_MAYBE_NULL))
        |                              ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~

Workaround the warning by moving the type_may_be_null() helper from
verifier.c into bpf_verifier.h, and reuse it here to check whether param
is nullable.

Fixes: 980ca8ceeae6 ("bpf: check bpf_dummy_struct_ops program params for test runs")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202404241956.HEiRYwWq-lkp@intel.com/
Signed-off-by: Shung-Hsi Yu 
Acked-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20240905055233.70203-1-shung-hsi.yu@suse.com
Signed-off-by: Alexei Starovoitov

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2024-07-09T15:01:46+00:00

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-07-08

The following pull-request contains BPF updates for your *net-next* tree.

We've added 102 non-merge commits during the last 28 day(s) which contain
a total of 127 files changed, 4606 insertions(+), 980 deletions(-).

The main changes are:

1) Support resilient split BTF which cuts down on duplication and makes BTF
   as compact as possible wrt BTF from modules, from Alan Maguire & Eduard Zingerman.

2) Add support for dumping kfunc prototypes from BTF which enables both detecting
   as well as dumping compilable prototypes for kfuncs, from Daniel Xu.

3) Batch of s390x BPF JIT improvements to add support for BPF arena and to implement
   support for BPF exceptions, from Ilya Leoshkevich.

4) Batch of riscv64 BPF JIT improvements in particular to add 12-argument support
   for BPF trampolines and to utilize bpf_prog_pack for the latter, from Pu Lehui.

5) Extend BPF test infrastructure to add a CHECKSUM_COMPLETE validation option
   for skbs and add coverage along with it, from Vadim Fedorenko.

6) Inline bpf_get_current_task/_btf() helpers in the arm64 BPF JIT which gives
   a small 1% performance improvement in micro-benchmarks, from Puranjay Mohan.

7) Extend the BPF verifier to track the delta between linked registers in order
   to better deal with recent LLVM code optimizations, from Alexei Starovoitov.

8) Fix bpf_wq_set_callback_impl() kfunc signature where the third argument should
   have been a pointer to the map value, from Benjamin Tissoires.

9) Extend BPF selftests to add regular expression support for test output matching
   and adjust some of the selftest when compiled under gcc, from Cupertino Miranda.

10) Simplify task_file_seq_get_next() and remove an unnecessary loop which always
    iterates exactly once anyway, from Dan Carpenter.

11) Add the capability to offload the netfilter flowtable in XDP layer through
    kfuncs, from Florian Westphal & Lorenzo Bianconi.

12) Various cleanups in networking helpers in BPF selftests to shave off a few
    lines of open-coded functions on client/server handling, from Geliang Tang.

13) Properly propagate prog->aux->tail_call_reachable out of BPF verifier, so
    that x86 JIT does not need to implement detection, from Leon Hwang.

14) Fix BPF verifier to add a missing check_func_arg_reg_off() to prevent an
    out-of-bounds memory access for dynpointers, from Matt Bobrowski.

15) Fix bpf_session_cookie() kfunc to return __u64 instead of long pointer as
    it might lead to problems on 32-bit archs, from Jiri Olsa.

16) Enhance traffic validation and dynamic batch size support in xsk selftests,
    from Tushar Vyavahare.

bpf-next-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (102 commits)
  selftests/bpf: DENYLIST.aarch64: Remove fexit_sleep
  selftests/bpf: amend for wrong bpf_wq_set_callback_impl signature
  bpf: helpers: fix bpf_wq_set_callback_impl signature
  libbpf: Add NULL checks to bpf_object__{prev_map,next_map}
  selftests/bpf: Remove exceptions tests from DENYLIST.s390x
  s390/bpf: Implement exceptions
  s390/bpf: Change seen_reg to a mask
  bpf: Remove unnecessary loop in task_file_seq_get_next()
  riscv, bpf: Optimize stack usage of trampoline
  bpf, devmap: Add .map_alloc_check
  selftests/bpf: Remove arena tests from DENYLIST.s390x
  selftests/bpf: Add UAF tests for arena atomics
  selftests/bpf: Introduce __arena_global
  s390/bpf: Support arena atomics
  s390/bpf: Enable arena
  s390/bpf: Support address space cast instruction
  s390/bpf: Support BPF_PROBE_MEM32
  s390/bpf: Land on the next JITed instruction after exception
  s390/bpf: Introduce pre- and post- probe functions
  s390/bpf: Get rid of get_probe_mem_regno()
  ...
====================

Link: https://patch.msgid.link/20240708221438.10974-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni