Recently, I frequently hit the following test failure:
[root@arch-fb-vm1 bpf]# ./test_progs -n 33/1
test_lookup_update:PASS:skel_open 0 nsec
[...]
test_lookup_update:PASS:sync_rcu 0 nsec
test_lookup_update:FAIL:map1_leak inner_map1 leaked!
#33/1 btf_map_in_map/lookup_update:FAIL
#33 btf_map_in_map:FAIL
In the test, after map is closed and then after two rcu grace periods,
it is assumed that map_id is not available to user space.
But the above assumption cannot be guaranteed. After zero or one
or two rcu grace periods in different siturations, the actual
freeing-map-work is put into a workqueue. Later on, when the work
is dequeued, the map will be actually freed.
See bpf_map_put() in kernel/bpf/syscall.c.
By using workqueue, there is no ganrantee that map will be actually
freed after a couple of rcu grace periods. This patch removed
such map leak detection and then the test can pass consistently.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240322061353.632136-1-yonghong.song@linux.dev
Add test validating BPF cookie can be passed during raw_tp/tp_btf
attachment and can be retried at runtime with bpf_get_attach_cookie()
helper.
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Message-ID: <20240319233852.1977493-6-andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Refactor some functions in both user space code and bpf program
as these functions are used by later cgroup/sk_msg tests.
Another change is to mark tp program optional loading as later
patches will use optional loading as well since they have quite
different attachment and testing logic.
There is no functionality change.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240315184904.2976123-1-yonghong.song@linux.dev
Replace CHECK in selftest ns_current_pid_tgid with recommended ASSERT_* style.
I also shortened subtest name as the prefix of subtest name is covered
by the test name already.
This patch does fix a testing issue. Currently even if bss->user_{pid,tgid}
is not correct, the test still passed since the clone func returns 0.
I fixed it to return a non-zero value if bss->user_{pid,tgid} is incorrect.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20240315184859.2975543-1-yonghong.song@linux.dev
A new version of a type may have additional fields that do not exist in
older versions. Previously, libbpf would reject struct_ops maps with a new
version containing extra fields when running on a machine with an old
kernel. However, we have updated libbpf to ignore these fields if their
values are all zeros or null in order to provide backward compatibility.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240313214139.685112-3-thinker.li@gmail.com
Alexei Starovoitov says:
====================
pull-request: bpf-next 2024-03-11
We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).
The main changes are:
1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
from Alexei.
2) Introduce bpf_arena which is sparse shared memory region between bpf
program and user space where structures inside the arena can have
pointers to other areas of the arena, and pointers work seamlessly for
both user-space programs and bpf programs, from Alexei and Andrii.
3) Introduce may_goto instruction that is a contract between the verifier
and the program. The verifier allows the program to loop assuming it's
behaving well, but reserves the right to terminate it, from Alexei.
4) Use IETF format for field definitions in the BPF standard
document, from Dave.
5) Extend struct_ops libbpf APIs to allow specify version suffixes for
stuct_ops map types, share the same BPF program between several map
definitions, and other improvements, from Eduard.
6) Enable struct_ops support for more than one page in trampolines,
from Kui-Feng.
7) Support kCFI + BPF on riscv64, from Puranjay.
8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.
9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================
Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add unit tests for bpf_arena_alloc/free_pages() functionality
and bpf_arena_common.h with a set of common helpers and macros that
is used in this test and the following patches.
Also modify test_loader that didn't support running bpf_prog_type_syscall
programs.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240308010812.89848-13-alexei.starovoitov@gmail.com
Check that autocreate flags of struct_ops map cause autoload of
struct_ops corresponding programs:
- when struct_ops program is referenced only from a map for which
autocreate is set to false, that program should not be loaded;
- when struct_ops program with autoload == false is set to be used
from a map with autocreate == true using shadow var,
that program should be loaded;
- when struct_ops program is not referenced from any map object load
should fail.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-10-eddyz87@gmail.com
When loading struct_ops programs kernel requires BTF id of the
struct_ops type and member index for attachment point inside that
type. This makes impossible to use same BPF program in several
struct_ops maps that have different struct_ops type.
Check if libbpf rejects such BPF objects files.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-7-eddyz87@gmail.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2024-02-29
We've added 119 non-merge commits during the last 32 day(s) which contain
a total of 150 files changed, 3589 insertions(+), 995 deletions(-).
The main changes are:
1) Extend the BPF verifier to enable static subprog calls in spin lock
critical sections, from Kumar Kartikeya Dwivedi.
2) Fix confusing and incorrect inference of PTR_TO_CTX argument type
in BPF global subprogs, from Andrii Nakryiko.
3) Larger batch of riscv BPF JIT improvements and enabling inlining
of the bpf_kptr_xchg() for RV64, from Pu Lehui.
4) Allow skeleton users to change the values of the fields in struct_ops
maps at runtime, from Kui-Feng Lee.
5) Extend the verifier's capabilities of tracking scalars when they
are spilled to stack, especially when the spill or fill is narrowing,
from Maxim Mikityanskiy & Eduard Zingerman.
6) Various BPF selftest improvements to fix errors under gcc BPF backend,
from Jose E. Marchesi.
7) Avoid module loading failure when the module trying to register
a struct_ops has its BTF section stripped, from Geliang Tang.
8) Annotate all kfuncs in .BTF_ids section which eventually allows
for automatic kfunc prototype generation from bpftool, from Daniel Xu.
9) Several updates to the instruction-set.rst IETF standardization
document, from Dave Thaler.
10) Shrink the size of struct bpf_map resp. bpf_array,
from Alexei Starovoitov.
11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer,
from Benjamin Tissoires.
12) Fix bpftool to be more portable to musl libc by using POSIX's
basename(), from Arnaldo Carvalho de Melo.
13) Add libbpf support to gcc in CORE macro definitions,
from Cupertino Miranda.
14) Remove a duplicate type check in perf_event_bpf_event,
from Florian Lehner.
15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them
with notrace correctly, from Yonghong Song.
16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible
array to fix build warnings, from Kees Cook.
17) Fix resolve_btfids cross-compilation to non host-native endianness,
from Viktor Malik.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
selftests/bpf: Test if shadow types work correctly.
bpftool: Add an example for struct_ops map and shadow type.
bpftool: Generated shadow variables for struct_ops maps.
libbpf: Convert st_ops->data to shadow type.
libbpf: Set btf_value_type_id of struct bpf_map for struct_ops.
bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
bpf, arm64: use bpf_prog_pack for memory management
arm64: patching: implement text_poke API
bpf, arm64: support exceptions
arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT
bpf: add is_async_callback_calling_insn() helper
bpf: introduce in_sleepable() helper
bpf: allow more maps in sleepable bpf programs
selftests/bpf: Test case for lacking CFI stub functions.
bpf: Check cfi_stubs before registering a struct_ops type.
bpf: Clarify batch lookup/lookup_and_delete semantics
bpf, docs: specify which BPF_ABS and BPF_IND fields were zero
bpf, docs: Fix typos in instruction-set.rst
selftests/bpf: update tcp_custom_syncookie to use scalar packet offset
bpf: Shrink size of struct bpf_map/bpf_array.
...
====================
Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Change the values of fields, including scalar types and function pointers,
and check if the struct_ops map works as expected.
The test changes the field "test_2" of "testmod_1" from the pointer to
test_2() to pointer to test_3() and the field "data" to 13. The function
test_2() and test_3() both compute a new value for "test_2_result", but in
different way. By checking the value of "test_2_result", it ensures the
struct_ops map works as expected with changes through shadow types.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240229064523.2091270-6-thinker.li@gmail.com
Ensure struct_ops rejects the registration of struct_ops types without
proper CFI stub functions.
bpf_test_no_cfi.ko is a module that attempts to register a struct_ops type
called "bpf_test_no_cfi_ops" with cfi_stubs of NULL and non-NULL value.
The NULL one should fail, and the non-NULL one should succeed. The module
can only be loaded successfully if these registrations yield the expected
results.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240222021105.1180475-3-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Incorporate a test case to assess the handling of invalid flags or
task__nullable parameters passed to bpf_iter_task_new(). Prior to the
preceding commit, this scenario could potentially trigger a kernel panic.
However, with the previous commit, this test case is expected to function
correctly.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240217114152.1623-3-laoar.shao@gmail.com
This selftest is based on a Alexei's test adopted from an internal
user to troubleshoot another bug. During this exercise, a separate
racing bug was discovered between bpf_timer_cancel_and_free
and bpf_timer_cancel. The details can be found in the previous
patch.
This patch is to add a selftest that can trigger the bug.
I can trigger the UAF everytime in my qemu setup with KASAN. The idea
is to have multiple user space threads running in a tight loop to exercise
both bpf_map_update_elem (which calls into bpf_timer_cancel_and_free)
and bpf_timer_cancel.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20240215211218.990808-2-martin.lau@linux.dev
Under x86-64, when using bpf_probe_read_kernel{_str}() or
bpf_probe_read{_str}() to read vsyscall page, the read may trigger oops,
so add one test case to ensure that the problem is fixed. Beside those
four bpf helpers mentioned above, testing the read of vsyscall page by
using bpf_probe_read_user{_str} and bpf_copy_from_user{_task}() as well.
The test case passes the address of vsyscall page to these six helpers
and checks whether the returned values are expected:
1) For bpf_probe_read_kernel{_str}()/bpf_probe_read{_str}(), the
expected return value is -ERANGE as shown below:
bpf_probe_read_kernel_common
copy_from_kernel_nofault
// false, return -ERANGE
copy_from_kernel_nofault_allowed
2) For bpf_probe_read_user{_str}(), the expected return value is -EFAULT
as show below:
bpf_probe_read_user_common
copy_from_user_nofault
// false, return -EFAULT
__access_ok
3) For bpf_copy_from_user(), the expected return value is -EFAULT:
// return -EFAULT
bpf_copy_from_user
copy_from_user
_copy_from_user
// return false
access_ok
4) For bpf_copy_from_user_task(), the expected return value is -EFAULT:
// return -EFAULT
bpf_copy_from_user_task
access_process_vm
// return 0
vma_lookup()
// return 0
expand_stack()
The occurrence of oops depends on the availability of CPU SMAP [1]
feature and there are three possible configurations of vsyscall page in
the boot cmd-line: vsyscall={xonly|none|emulate}, so there are a total
of six possible combinations. Under all these combinations, the test
case runs successfully.
[1]: https://en.wikipedia.org/wiki/Supervisor_Mode_Access_Prevention
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20240202103935.3154011-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As BPF applications grow in size and complexity and are separated into
multiple .bpf.c files that are statically linked together, it becomes
harder and harder to match verifier's BPF assembly level output to
original C code. While often annotated C source code is unique enough to
be able to identify the file it belongs to, quite often this is actually
problematic as parts of source code can be quite generic.
Long story short, it is very useful to see source code file name and
line number information along with the original C code. Verifier already
knows this information, we just need to output it.
This patch extends verifier log with file name and line number
information, emitted next to original (presumably C) source code,
annotating BPF assembly output, like so:
; <original C code> @ <filename>.bpf.c:<line>
If file name has directory names in it, they are stripped away. This
should be fine in practice as file names tend to be pretty unique with
C code anyways, and keeping log size smaller is always good.
In practice this might look something like below, where some code is
coming from application files, while others are from libbpf's usdt.bpf.h
header file:
; if (STROBEMETA_READ( @ strobemeta_probe.bpf.c:534
5592: (79) r1 = *(u64 *)(r10 -56) ; R1_w=mem_or_null(id=1589,sz=7680) R10=fp0
5593: (7b) *(u64 *)(r10 -56) = r1 ; R1_w=mem_or_null(id=1589,sz=7680) R10=fp0
5594: (79) r3 = *(u64 *)(r10 -8) ; R3_w=scalar() R10=fp0 fp-8=mmmmmmmm
...
170: (71) r1 = *(u8 *)(r8 +15) ; frame1: R1_w=scalar(...) R8_w=map_value(map=__bpf_usdt_spec,ks=4,vs=208)
171: (67) r1 <<= 56 ; frame1: R1_w=scalar(...)
172: (c7) r1 s>>= 56 ; frame1: R1_w=scalar(smin=smin32=-128,smax=smax32=127)
; val <<= arg_spec->arg_bitshift; @ usdt.bpf.h:183
173: (67) r1 <<= 32 ; frame1: R1_w=scalar(...)
174: (77) r1 >>= 32 ; frame1: R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff))
175: (79) r2 = *(u64 *)(r10 -8) ; frame1: R2_w=scalar() R10=fp0 fp-8=mmmmmmmm
176: (6f) r2 <<= r1 ; frame1: R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R2_w=scalar()
177: (7b) *(u64 *)(r10 -8) = r2 ; frame1: R2_w=scalar(id=61) R10=fp0 fp-8_w=scalar(id=61)
; if (arg_spec->arg_signed) @ usdt.bpf.h:184
178: (bf) r3 = r2 ; frame1: R2_w=scalar(id=61) R3_w=scalar(id=61)
179: (7f) r3 >>= r1 ; frame1: R1_w=scalar(smin=0,smax=umax=0xffffffff,var_off=(0x0; 0xffffffff)) R3_w=scalar()
; if (arg_spec->arg_signed) @ usdt.bpf.h:184
180: (71) r4 = *(u8 *)(r8 +14)
181: safe
log_fixup tests needed a minor adjustment as verifier log output
increased a bit and that test is quite sensitive to such changes.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240212235944.2816107-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Test if the verifier verifies nullable pointer arguments correctly for BPF
struct_ops programs.
"test_maybe_null" in struct bpf_testmod_ops is the operator defined for the
test cases here.
A BPF program should check a pointer for NULL beforehand to access the
value pointed by the nullable pointer arguments, or the verifier should
reject the programs. The test here includes two parts; the programs
checking pointers properly and the programs not checking pointers
beforehand. The test checks if the verifier accepts the programs checking
properly and rejects the programs not checking at all.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240209023750.1153905-5-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Add selftests covering the following cases:
- A static or global subprog called from within a RCU read section works
- A static subprog taking an RCU read lock which is released in caller works
- A static subprog releasing the caller's RCU read lock works
Global subprogs that leave the lock in an imbalanced state will not
work, as they are verified separately, so ensure those cases fail as
well.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20240205055646.1112186-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add selftests for static subprog calls within bpf_spin_lock critical
section, and ensure we still reject global subprog calls. Also test the
case where a subprog call will unlock the caller's held lock, or the
caller will unlock a lock taken by a subprog call, ensuring correct
transfer of lock state across frames on exit.
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20240204222349.938118-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Recently, when running './test_progs -j', I occasionally hit the
following errors:
test_lwt_redirect:PASS:pthread_create 0 nsec
test_lwt_redirect_run:FAIL:netns_create unexpected error: 256 (errno 0)
#142/2 lwt_redirect/lwt_redirect_normal_nomac:FAIL
#142 lwt_redirect:FAIL
test_lwt_reroute:PASS:pthread_create 0 nsec
test_lwt_reroute_run:FAIL:netns_create unexpected error: 256 (errno 0)
test_lwt_reroute:PASS:pthread_join 0 nsec
#143/2 lwt_reroute/lwt_reroute_qdisc_dropped:FAIL
#143 lwt_reroute:FAIL
The netns_create() definition looks like below:
#define NETNS "ns_lwt"
static inline int netns_create(void)
{
return system("ip netns add " NETNS);
}
One possibility is that both lwt_redirect and lwt_reroute create
netns with the same name "ns_lwt" which may cause conflict. I tried
the following example:
$ sudo ip netns add abc
$ echo $?
0
$ sudo ip netns add abc
Cannot create namespace file "/var/run/netns/abc": File exists
$ echo $?
1
$
The return code for above netns_create() is 256. The internet search
suggests that the return value for 'ip netns add ns_lwt' is 1, which
matches the above 'sudo ip netns add abc' example.
This patch tried to use different netns names for two tests to avoid
'ip netns add <name>' failure.
I ran './test_progs -j' 10 times and all succeeded with
lwt_redirect/lwt_reroute tests.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240205052914.1742687-1-yonghong.song@linux.dev
After a recent change in the vmtest runner, this test started failing
sporadically.
Investigation showed that this test was subject to race condition which
got exacerbated after the vm runner change. The symptoms being that the
logic that waited for an ICMPv4 packet is naive and will break if 5 or
more non-ICMPv4 packets make it to tap0.
When ICMPv6 is enabled, the kernel will generate traffic such as ICMPv6
router solicitation...
On a system with good performance, the expected ICMPv4 packet would very
likely make it to the network interface promptly, but on a system with
poor performance, those "guarantees" do not hold true anymore.
Given that the test is IPv4 only, this change disable IPv6 in the test
netns by setting `net.ipv6.conf.all.disable_ipv6` to 1.
This essentially leaves "ping" as the sole generator of traffic in the
network namespace.
If this test was to be made IPv6 compatible, the logic in
`wait_for_packet` would need to be modified.
In more details...
At a high level, the test does:
- create a new namespace
- in `setup_redirect_target` set up lo, tap0, and link_err interfaces as
well as add 2 routes that attaches ingress/egress sections of
`test_lwt_redirect.bpf.o` to the xmit path.
- in `send_and_capture_test_packets` send an ICMP packet and read off
the tap interface (using `wait_for_packet`) to check that a ICMP packet
with the right size is read.
`wait_for_packet` will try to read `max_retry` (5) times from the tap0
fd looking for an ICMPv4 packet matching some criteria.
The problem is that when we set up the `tap0` interface, because IPv6 is
enabled by default, traffic such as Router solicitation is sent through
tap0, as in:
# tcpdump -r /tmp/lwt_redirect.pc
reading from file /tmp/lwt_redirect.pcap, link-type EN10MB (Ethernet)
04:46:23.578352 IP6 :: > ff02::1:ffc0:4427: ICMP6, neighbor solicitation, who has fe80::fcba:dff:fec0:4427, length 32
04:46:23.659522 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
04:46:24.389169 IP 10.0.0.1 > 20.0.0.9: ICMP echo request, id 122, seq 1, length 108
04:46:24.618599 IP6 fe80::fcba:dff:fec0:4427 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
04:46:24.619985 IP6 fe80::fcba:dff:fec0:4427 > ff02::2: ICMP6, router solicitation, length 16
04:46:24.767326 IP6 fe80::fcba:dff:fec0:4427 > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
04:46:28.936402 IP6 fe80::fcba:dff:fec0:4427 > ff02::2: ICMP6, router solicitation, length 16
If `wait_for_packet` sees 5 non-ICMPv4 packets, it will return 0, which is what we see in:
2024-01-31T03:51:25.0336992Z test_lwt_redirect_run:PASS:netns_create 0 nsec
2024-01-31T03:51:25.0341309Z open_netns:PASS:malloc token 0 nsec
2024-01-31T03:51:25.0344844Z open_netns:PASS:open /proc/self/ns/net 0 nsec
2024-01-31T03:51:25.0350071Z open_netns:PASS:open netns fd 0 nsec
2024-01-31T03:51:25.0353516Z open_netns:PASS:setns 0 nsec
2024-01-31T03:51:25.0356560Z test_lwt_redirect_run:PASS:setns 0 nsec
2024-01-31T03:51:25.0360140Z open_tuntap:PASS:open(/dev/net/tun) 0 nsec
2024-01-31T03:51:25.0363822Z open_tuntap:PASS:ioctl(TUNSETIFF) 0 nsec
2024-01-31T03:51:25.0367402Z open_tuntap:PASS:fcntl(O_NONBLOCK) 0 nsec
2024-01-31T03:51:25.0371167Z setup_redirect_target:PASS:open_tuntap 0 nsec
2024-01-31T03:51:25.0375180Z setup_redirect_target:PASS:if_nametoindex 0 nsec
2024-01-31T03:51:25.0379929Z setup_redirect_target:PASS:ip link add link_err type dummy 0 nsec
2024-01-31T03:51:25.0384874Z setup_redirect_target:PASS:ip link set lo up 0 nsec
2024-01-31T03:51:25.0389678Z setup_redirect_target:PASS:ip addr add dev lo 10.0.0.1/32 0 nsec
2024-01-31T03:51:25.0394814Z setup_redirect_target:PASS:ip link set link_err up 0 nsec
2024-01-31T03:51:25.0399874Z setup_redirect_target:PASS:ip link set tap0 up 0 nsec
2024-01-31T03:51:25.0407731Z setup_redirect_target:PASS:ip route add 10.0.0.0/24 dev link_err encap bpf xmit obj test_lwt_redirect.bpf.o sec redir_ingress 0 nsec
2024-01-31T03:51:25.0419105Z setup_redirect_target:PASS:ip route add 20.0.0.0/24 dev link_err encap bpf xmit obj test_lwt_redirect.bpf.o sec redir_egress 0 nsec
2024-01-31T03:51:25.0427209Z test_lwt_redirect_normal:PASS:setup_redirect_target 0 nsec
2024-01-31T03:51:25.0431424Z ping_dev:PASS:if_nametoindex 0 nsec
2024-01-31T03:51:25.0437222Z send_and_capture_test_packets:FAIL:wait_for_epacket unexpected wait_for_epacket: actual 0 != expected 1
2024-01-31T03:51:25.0448298Z (/tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/lwt_redirect.c:175: errno: Success) test_lwt_redirect_normal egress test fails
2024-01-31T03:51:25.0457124Z close_netns:PASS:setns 0 nsec
When running in a VM which potential resource contrains, the odds that calling
`ping` is not scheduled very soon after bringing `tap0` up increases,
and with this the chances to get our ICMP packet pushed to position 6+
in the network trace.
To confirm this indeed solves the issue, I ran the test 100 times in a
row with:
errors=0
successes=0
for i in `seq 1 100`
do
./test_progs -t lwt_redirect/lwt_redirect_normal
if [ $? -eq 0 ]; then
successes=$((successes+1))
else
errors=$((errors+1))
fi
done
echo "successes: $successes/errors: $errors"
While this test would at least fail a couple of time every 10 runs, here
it ran 100 times with no error.
Fixes: 43a7c3ef8a ("selftests/bpf: Add lwt_xmit tests for BPF_REDIRECT")
Signed-off-by: Manu Bretelle <chantr4@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240131053212.2247527-1-chantr4@gmail.com
In s390, CI reported that the sock_iter_batch selftest
hits this error very often:
2024-01-26T16:56:49.3091804Z Bind /proc/self/ns/net -> /run/netns/sock_iter_batch_netns failed: No such file or directory
2024-01-26T16:56:49.3149524Z Cannot remove namespace file "/run/netns/sock_iter_batch_netns": No such file or directory
2024-01-26T16:56:49.3772213Z test_sock_iter_batch:FAIL:ip netns add sock_iter_batch_netns unexpected error: 256 (errno 0)
It happens very often in s390 but Manu also noticed it happens very
sparsely in other arch also.
It turns out the default dash shell does not recognize "&>"
as a redirection operator, so the command went to the background.
In the sock_iter_batch selftest, the "ip netns delete" went
into background and then race with the following "ip netns add"
command.
This patch replaces the "&> /dev/null" usage with ">/dev/null 2>&1"
and does this redirection in the SYS_NOFAIL macro instead of doing
it individually by its caller. The SYS_NOFAIL callers do not care
about failure, so it is no harm to do this redirection even if
some of the existing callers do not redirect to /dev/null now.
It touches different test files, so I skipped the Fixes tags
in this patch. Some of the changed tests do not use "&>"
but they use the SYS_NOFAIL, so these tests are also
changed to avoid doing its own redirection because
SYS_NOFAIL does it internally now.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240127025017.950825-1-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add tests for LSM interactions (both bpf_token_capable and bpf_token_cmd
LSM hooks) with BPF token in bpf() subsystem. Now child process passes
back token FD for parent to be able to do tests with token originating
in "wrong" userns. But we also create token in initns and check that
token LSMs don't accidentally reject BPF operations when capable()
checks pass without BPF token.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-31-andrii@kernel.org
Add a selftest that attempts to conceptually replicate intended BPF
token use cases inside user namespaced container.
Child process is forked. It is then put into its own userns and mountns.
Child creates BPF FS context object. This ensures child userns is
captured as the owning userns for this instance of BPF FS. Given setting
delegation mount options is privileged operation, we ensure that child
cannot set them.
This context is passed back to privileged parent process through Unix
socket, where parent sets up delegation options, creates, and mounts it
as a detached mount. This mount FD is passed back to the child to be
used for BPF token creation, which allows otherwise privileged BPF
operations to succeed inside userns.
We validate that all of token-enabled privileged commands (BPF_BTF_LOAD,
BPF_MAP_CREATE, and BPF_PROG_LOAD) work as intended. They should only
succeed inside the userns if a) BPF token is provided with proper
allowed sets of commands and types; and b) namespaces CAP_BPF and other
privileges are set. Lacking a) or b) should lead to -EPERM failures.
Based on suggested workflow by Christian Brauner ([0]).
[0] https://lore.kernel.org/bpf/20230704-hochverdient-lehne-eeb9eeef785e@brauner/
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-17-andrii@kernel.org
Add basic support of BPF token to BPF_PROG_LOAD. BPF_F_TOKEN_FD flag
should be set in prog_flags field when providing prog_token_fd.
Wire through a set of allowed BPF program types and attach types,
derived from BPF FS at BPF token creation time. Then make sure we
perform bpf_token_capable() checks everywhere where it's relevant.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-7-andrii@kernel.org
Allow providing token_fd for BPF_MAP_CREATE command to allow controlled
BPF map creation from unprivileged process through delegated BPF token.
New BPF_F_TOKEN_FD flag is added to specify together with BPF token FD
for BPF_MAP_CREATE command.
Wire through a set of allowed BPF map types to BPF token, derived from
BPF FS at BPF token creation time. This, in combination with allowed_cmds
allows to create a narrowly-focused BPF token (controlled by privileged
agent) with a restrictive set of BPF maps that application can attempt
to create.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-5-andrii@kernel.org
