[ Upstream commit d4965578267e2e81f67c86e2608481e77e9c8569 ] bpf_map_lookup_percpu_elem() helper is also available for sleepable bpf program. When BPF JIT is disabled or under 32-bit host, bpf_map_lookup_percpu_elem() will not be inlined. Using it in a sleepable bpf program will trigger the warning in bpf_map_lookup_percpu_elem(), because the bpf program only holds rcu_read_lock_trace lock. Therefore, add the missed check. Reported-by: syzbot+dce5aae19ae4d6399986@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000176a130617420310@google.com/ Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20250526062534.1105938-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 86bc9c742426a16b52a10ef61f5b721aecca2344 ]
syzkaller reported an issue:
WARNING: CPU: 3 PID: 217 at kernel/bpf/core.c:2357 __bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357
Modules linked in:
CPU: 3 UID: 0 PID: 217 Comm: kworker/u32:6 Not tainted 6.15.0-rc4-syzkaller-00040-g8bac8898fe39
RIP: 0010:__bpf_prog_ret0_warn+0xa/0x20 kernel/bpf/core.c:2357
Call Trace:
<TASK>
bpf_dispatcher_nop_func include/linux/bpf.h:1316 [inline]
__bpf_prog_run include/linux/filter.h:718 [inline]
bpf_prog_run include/linux/filter.h:725 [inline]
cls_bpf_classify+0x74a/0x1110 net/sched/cls_bpf.c:105
...
When creating bpf program, 'fp->jit_requested' depends on bpf_jit_enable.
This issue is triggered because of CONFIG_BPF_JIT_ALWAYS_ON is not set
and bpf_jit_enable is set to 1, causing the arch to attempt JIT the prog,
but jit failed due to FAULT_INJECTION. As a result, incorrectly
treats the program as valid, when the program runs it calls
`__bpf_prog_ret0_warn` and triggers the WARN_ON_ONCE(1).
Reported-by: syzbot+0903f6d7f285e41cdf10@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/6816e34e.a70a0220.254cdc.002c.GAE@google.com
Fixes: fa9dd599b4da ("bpf: get rid of pure_initcall dependency to enable jits")
Signed-off-by: KaFai Wan <mannkafai@gmail.com>
Link: https://lore.kernel.org/r/20250526133358.2594176-1-mannkafai@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 714070c4cb7a10ff57450a618a936775f3036245 ]
In the current implementation if the program is dev-bound to a specific
device, it will not be possible to perform XDP_REDIRECT into a DEVMAP
or CPUMAP even if the program is running in the driver NAPI context and
it is not attached to any map entry. This seems in contrast with the
explanation available in bpf_prog_map_compatible routine.
Fix the issue introducing __bpf_prog_map_compatible utility routine in
order to avoid bpf_prog_is_dev_bound() check running bpf_check_tail_call()
at program load time (bpf_prog_select_runtime()).
Continue forbidding to attach a dev-bound program to XDP maps
(BPF_MAP_TYPE_PROG_ARRAY, BPF_MAP_TYPE_DEVMAP and BPF_MAP_TYPE_CPUMAP).
Fixes: 3d76a4d3d4e59 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9e63fdb0cbdf3268c86638a8274f4d5549a82820 ] verifier.c:is_state_visited() uses RANGE_WITHIN states comparison rules for cached states that have loop_entry with non-zero branches count (meaning that loop_entry's verification is not yet done). The RANGE_WITHIN rules in regsafe()/stacksafe() require register and stack objects types to be identical in current and old states. verifier.c:clean_live_states() replaces registers and stack spills with NOT_INIT/STACK_INVALID marks, if these registers/stack spills are not read in any child state. This means that clean_live_states() works against loop convergence logic under some conditions. See selftest in the next patch for a specific example. Mitigate this by prohibiting clean_verifier_state() when state->loop_entry->branches > 0. This undoes negative verification performance impact of the copy_verifier_state() fix from the previous patch. Below is comparison between master and current patch. selftests: File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF) ---------------------------------- ---------------------------- --------- --------- --------------- ---------- ---------- -------------- arena_htab.bpf.o arena_htab_llvm 717 423 -294 (-41.00%) 57 37 -20 (-35.09%) arena_htab_asm.bpf.o arena_htab_asm 597 445 -152 (-25.46%) 47 37 -10 (-21.28%) arena_list.bpf.o arena_list_add 1493 1822 +329 (+22.04%) 30 37 +7 (+23.33%) arena_list.bpf.o arena_list_del 309 261 -48 (-15.53%) 23 15 -8 (-34.78%) iters.bpf.o checkpoint_states_deletion 18125 22154 +4029 (+22.23%) 818 918 +100 (+12.22%) iters.bpf.o iter_nested_deeply_iters 593 367 -226 (-38.11%) 67 43 -24 (-35.82%) iters.bpf.o iter_nested_iters 813 772 -41 (-5.04%) 79 72 -7 (-8.86%) iters.bpf.o iter_subprog_check_stacksafe 155 135 -20 (-12.90%) 15 14 -1 (-6.67%) iters.bpf.o iter_subprog_iters 1094 808 -286 (-26.14%) 88 68 -20 (-22.73%) iters.bpf.o loop_state_deps2 479 356 -123 (-25.68%) 46 35 -11 (-23.91%) iters.bpf.o triple_continue 35 31 -4 (-11.43%) 3 3 +0 (+0.00%) kmem_cache_iter.bpf.o open_coded_iter 63 59 -4 (-6.35%) 7 6 -1 (-14.29%) mptcp_subflow.bpf.o _getsockopt_subflow 501 446 -55 (-10.98%) 25 23 -2 (-8.00%) pyperf600_iter.bpf.o on_event 12339 6379 -5960 (-48.30%) 441 286 -155 (-35.15%) verifier_bits_iter.bpf.o max_words 92 84 -8 (-8.70%) 8 7 -1 (-12.50%) verifier_iterating_callbacks.bpf.o cond_break2 113 192 +79 (+69.91%) 12 21 +9 (+75.00%) sched_ext: File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF) ----------------- ---------------------- --------- --------- ----------------- ---------- ---------- ---------------- bpf.bpf.o layered_dispatch 11485 9039 -2446 (-21.30%) 848 662 -186 (-21.93%) bpf.bpf.o layered_dump 7422 5022 -2400 (-32.34%) 681 298 -383 (-56.24%) bpf.bpf.o layered_enqueue 16854 13753 -3101 (-18.40%) 1611 1308 -303 (-18.81%) bpf.bpf.o layered_init 1000001 5549 -994452 (-99.45%) 84672 523 -84149 (-99.38%) bpf.bpf.o layered_runnable 3149 1899 -1250 (-39.70%) 288 151 -137 (-47.57%) bpf.bpf.o p2dq_init 2343 1936 -407 (-17.37%) 201 170 -31 (-15.42%) bpf.bpf.o refresh_layer_cpumasks 16487 1285 -15202 (-92.21%) 1770 120 -1650 (-93.22%) bpf.bpf.o rusty_select_cpu 1937 1386 -551 (-28.45%) 177 125 -52 (-29.38%) scx_central.bpf.o central_dispatch 636 600 -36 (-5.66%) 63 59 -4 (-6.35%) scx_central.bpf.o central_init 913 632 -281 (-30.78%) 48 39 -9 (-18.75%) scx_nest.bpf.o nest_init 636 601 -35 (-5.50%) 60 58 -2 (-3.33%) scx_pair.bpf.o pair_dispatch 1000001 1914 -998087 (-99.81%) 58169 142 -58027 (-99.76%) scx_qmap.bpf.o qmap_dispatch 2393 2187 -206 (-8.61%) 196 174 -22 (-11.22%) scx_qmap.bpf.o qmap_init 16367 22777 +6410 (+39.16%) 603 768 +165 (+27.36%) 'layered_init' and 'pair_dispatch' hit 1M on master, but are verified ok with this patch. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20250215110411.3236773-4-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4b82b181a26cff8bf7adc3a85a88d121d92edeaf ]
Currently for bpf progs in a cgroup hierarchy, the effective prog array
is computed from bottom cgroup to upper cgroups (post-ordering). For
example, the following cgroup hierarchy
root cgroup: p1, p2
subcgroup: p3, p4
have BPF_F_ALLOW_MULTI for both cgroup levels.
The effective cgroup array ordering looks like
p3 p4 p1 p2
and at run time, progs will execute based on that order.
But in some cases, it is desirable to have root prog executes earlier than
children progs (pre-ordering). For example,
- prog p1 intends to collect original pkt dest addresses.
- prog p3 will modify original pkt dest addresses to a proxy address for
security reason.
The end result is that prog p1 gets proxy address which is not what it
wants. Putting p1 to every child cgroup is not desirable either as it
will duplicate itself in many child cgroups. And this is exactly a use case
we are encountering in Meta.
To fix this issue, let us introduce a flag BPF_F_PREORDER. If the flag
is specified at attachment time, the prog has higher priority and the
ordering with that flag will be from top to bottom (pre-ordering).
For example, in the above example,
root cgroup: p1, p2
subcgroup: p3, p4
Let us say p2 and p4 are marked with BPF_F_PREORDER. The final
effective array ordering will be
p2 p4 p3 p1
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250224230116.283071-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 07651ccda9ff10a8ca427670cdd06ce2c8e4269c ] Return prog's btf_id from bpf_prog_get_info_by_fd regardless of capable check. This patch enables scenario, when freplace program, running from user namespace, requires to query target prog's btf. Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20250317174039.161275-3-mykyta.yatsenko5@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 75673fda0c557ae26078177dd14d4857afbf128d ] The _safe variant used here gets the next element before running the callback, avoiding the endless loop condition. Signed-off-by: Brandon Kammerdiener <brandon.kammerdiener@intel.com> Link: https://lore.kernel.org/r/20250424153246.141677-2-brandon.kammerdiener@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ac6542ad92759cda383ad62b4e4cbfc28136abc1 upstream.
bpf_prog_aux->func field might be NULL if program does not have
subprograms except for main sub-program. The fixed commit does
bpf_prog_aux->func access unconditionally, which might lead to null
pointer dereference.
The bug could be triggered by replacing the following BPF program:
SEC("tc")
int main_changes(struct __sk_buff *sk)
{
bpf_skb_pull_data(sk, 0);
return 0;
}
With the following BPF program:
SEC("freplace")
long changes_pkt_data(struct __sk_buff *sk)
{
return bpf_skb_pull_data(sk, 0);
}
bpf_prog_aux instance itself represents the main sub-program,
use this property to fix the bug.
Fixes: 81f6d0530ba0 ("bpf: check changes_pkt_data property for extension programs")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202412111822.qGw6tOyB-lkp@intel.com/
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241212070711.427443-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 81f6d0530ba031b5f038a091619bf2ff29568852 upstream.
When processing calls to global sub-programs, verifier decides whether
to invalidate all packet pointers in current state depending on the
changes_pkt_data property of the global sub-program.
Because of this, an extension program replacing a global sub-program
must be compatible with changes_pkt_data property of the sub-program
being replaced.
This commit:
- adds changes_pkt_data flag to struct bpf_prog_aux:
- this flag is set in check_cfg() for main sub-program;
- in jit_subprogs() for other sub-programs;
- modifies bpf_check_attach_btf_id() to check changes_pkt_data flag;
- moves call to check_attach_btf_id() after the call to check_cfg(),
because it needs changes_pkt_data flag to be set:
bpf_check:
... ...
- check_attach_btf_id resolve_pseudo_ldimm64
resolve_pseudo_ldimm64 --> bpf_prog_is_offloaded
bpf_prog_is_offloaded check_cfg
check_cfg + check_attach_btf_id
... ...
The following fields are set by check_attach_btf_id():
- env->ops
- prog->aux->attach_btf_trace
- prog->aux->attach_func_name
- prog->aux->attach_func_proto
- prog->aux->dst_trampoline
- prog->aux->mod
- prog->aux->saved_dst_attach_type
- prog->aux->saved_dst_prog_type
- prog->expected_attach_type
Neither of these fields are used by resolve_pseudo_ldimm64() or
bpf_prog_offload_verifier_prep() (for netronome and netdevsim
drivers), so the reordering is safe.
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241210041100.1898468-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[ shung-hsi.yu: adapt to missing fields in "struct bpf_prog_aux". Context
difference in jit_subprogs() because BPF Exception is not supported. Context
difference in bpf_check() because commit 5b5f51bff1b6 "bpf:
no_caller_saved_registers attribute for helper calls" is not present. ]
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 51081a3f25c742da5a659d7fc6fd77ebfdd555be upstream.
When processing calls to certain helpers, verifier invalidates all
packet pointers in a current state. For example, consider the
following program:
__attribute__((__noinline__))
long skb_pull_data(struct __sk_buff *sk, __u32 len)
{
return bpf_skb_pull_data(sk, len);
}
SEC("tc")
int test_invalidate_checks(struct __sk_buff *sk)
{
int *p = (void *)(long)sk->data;
if ((void *)(p + 1) > (void *)(long)sk->data_end) return TCX_DROP;
skb_pull_data(sk, 0);
*p = 42;
return TCX_PASS;
}
After a call to bpf_skb_pull_data() the pointer 'p' can't be used
safely. See function filter.c:bpf_helper_changes_pkt_data() for a list
of such helpers.
At the moment verifier invalidates packet pointers when processing
helper function calls, and does not traverse global sub-programs when
processing calls to global sub-programs. This means that calls to
helpers done from global sub-programs do not invalidate pointers in
the caller state. E.g. the program above is unsafe, but is not
rejected by verifier.
This commit fixes the omission by computing field
bpf_subprog_info->changes_pkt_data for each sub-program before main
verification pass.
changes_pkt_data should be set if:
- subprogram calls helper for which bpf_helper_changes_pkt_data
returns true;
- subprogram calls a global function,
for which bpf_subprog_info->changes_pkt_data should be set.
The verifier.c:check_cfg() pass is modified to compute this
information. The commit relies on depth first instruction traversal
done by check_cfg() and absence of recursive function calls:
- check_cfg() would eventually visit every call to subprogram S in a
state when S is fully explored;
- when S is fully explored:
- every direct helper call within S is explored
(and thus changes_pkt_data is set if needed);
- every call to subprogram S1 called by S was visited with S1 fully
explored (and thus S inherits changes_pkt_data from S1).
The downside of such approach is that dead code elimination is not
taken into account: if a helper call inside global function is dead
because of current configuration, verifier would conservatively assume
that the call occurs for the purpose of the changes_pkt_data
computation.
Reported-by: Nick Zavaritsky <mejedi@gmail.com>
Closes: https://lore.kernel.org/bpf/0498CA22-5779-4767-9C0C-A9515CEA711F@gmail.com/
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20241210041100.1898468-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[shung-hsi.yu: do not use bitfield in "struct bpf_subprog_info" because commit
406a6fa44bfb ("bpf: use bitfields for simple per-subprog bool flags") is not
present and minor context difference in check_func_call() because commit
491dd8edecbc ("bpf: Emit global subprog name in verifier logs") is not present. ]
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>