CO-RE accessor strings are colon-separated indices that describe a path
from a root BTF type to a target field, e.g. "0:1:2" walks through
nested struct members. bpf_core_parse_spec() parses each component with
sscanf("%d"), so negative values like -1 are silently accepted. The
subsequent bounds checks (access_idx >= btf_vlen(t)) only guard the
upper bound and always pass for negative values because C integer
promotion converts the __u16 btf_vlen result to int, making the
comparison (int)(-1) >= (int)(N) false for any positive N.
When -1 reaches btf_member_bit_offset() it gets cast to u32 0xffffffff,
producing an out-of-bounds read far past the members array. A crafted
BPF program with a negative CO-RE accessor on any struct that exists in
vmlinux BTF (e.g. task_struct) crashes the kernel deterministically
during BPF_PROG_LOAD on any system with CONFIG_DEBUG_INFO_BTF=y
(default on major distributions). The bug is reachable with CAP_BPF:
BUG: unable to handle page fault for address: ffffed11818b6626
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 85 Comm: poc Not tainted 7.0.0-rc6 #18 PREEMPT(full)
RIP: 0010:bpf_core_parse_spec (tools/lib/bpf/relo_core.c:354)
RAX: 00000000ffffffff
Call Trace:
<TASK>
bpf_core_calc_relo_insn (tools/lib/bpf/relo_core.c:1321)
bpf_core_apply (kernel/bpf/btf.c:9507)
check_core_relo (kernel/bpf/verifier.c:19475)
bpf_check (kernel/bpf/verifier.c:26031)
bpf_prog_load (kernel/bpf/syscall.c:3089)
__sys_bpf (kernel/bpf/syscall.c:6228)
</TASK>
CO-RE accessor indices are inherently non-negative (struct member index,
array element index, or enumerator index), so reject them immediately
after parsing.
Fixes: ddc7c30426 ("libbpf: implement BPF CO-RE offset relocation algorithm")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260404161221.961828-2-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_lsm_task_to_inode() is called under rcu_read_lock() and
bpf_lsm_inet_conn_established() is called from softirq context, so
neither hook can be used by sleepable LSM programs.
Fixes: 423f16108c ("bpf: Augment the set of sleepable LSM hooks")
Reported-by: Quan Sun <2022090917019@std.uestc.edu.cn>
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Reported-by: Dongliang Mu <dzm91@hust.edu.cn>
Closes: https://lore.kernel.org/bpf/3ab69731-24d1-431a-a351-452aafaaf2a5@std.uestc.edu.cn/T/#u
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://lore.kernel.org/r/20260407122334.344072-1-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A `gotox rX` instruction accepts only values of type PTR_TO_INSN.
The only way to create such a value is to load it from a map of
type insn_array:
rX = *(rY + offset) # rY was read from an insn_array
...
gotox rX
Add instruction-level and C-level selftests to validate loads
with nonzero offsets.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20260406160141.36943-3-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When a pointer to PTR_TO_INSN is dereferenced, the offset field
of the BPF_LDX_MEM instruction can be nonzero. Patch the verifier
to not ignore this field.
Reported-by: Jiyong Yang <ksur673@gmail.com>
Fixes: 493d9e0d60 ("bpf, x86: add support for indirect jumps")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20260406160141.36943-2-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Apparently, struct bpf_empty_prog_array exists entirely to populate a
single element of "items" in a global variable. "null_prog" is only
used during the initializer.
None of this is needed; globals will be correctly sized with an array
initializer of a flexible-array member.
So, remove struct bpf_empty_prog_array and adjust the rest of the code,
accordingly.
With these changes, fix the following warnings:
./include/linux/bpf.h:2369:31: warning: structure containing a flexible
array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/acr7Whmn0br3xeBP@kspp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Kumar Kartikeya Dwivedi says:
====================
Allow variable offsets for syscall PTR_TO_CTX
Enable pointer modification with variable offsets accumulated in the
register for PTR_TO_CTX for syscall programs where it won't be
rewritten, and the context is user-supplied and checked against the max
offset. See patches for details. Fixed offset support landed in [0].
By combining this set with [0], examples like the one below should
succeed verification now.
SEC("syscall")
int prog(void *ctx) {
int *arr = ctx;
int i;
bpf_for(i, 0, 100)
arr[i] *= i;
return 0;
}
[0]: https://lore.kernel.org/bpf/20260227005725.1247305-1-memxor@gmail.com
Changelog:
----------
v4 -> v5
v4: https://lore.kernel.org/bpf/20260401122818.2240807-1-memxor@gmail.com
* Use is_var_ctx_off_allowed() consistently.
* Add acks. (Emil)
v3 -> v4
v3: https://lore.kernel.org/bpf/20260318103526.2590079-1-memxor@gmail.com
* Drop comment around describing choice of fixed or variable offsets. (Eduard)
* Simplify offset adjustment for different cases. (Eduard)
* Add PTR_TO_CTX case in __check_mem_access(). (Eduard)
* Drop aligned access constraint from syscall_prog_is_valid_access().
* Wrap naked checks for BPF_PROG_TYPE_SYSCALL in a utility function. (Eduard)
* Split tests into separate clean up and addition patches. (Eduard)
* Remove CAP_SYS_ADMIN changes. (Eduard)
* Enable unaligned access to syscall ctx, add tests.
* Add more tests for various corner cases.
* Add acks. (Puranjay, Mykyta)
v2 -> v3
v2: https://lore.kernel.org/bpf/20260318075133.1031781-1-memxor@gmail.com
* Prevent arg_type for KF_ARG_PTR_TO_CTX from applying to other cases
due to preceding fallthrough. (Gemini/Sashiko)
v1 -> v2
v1: https://lore.kernel.org/bpf/20260317111850.2107846-2-memxor@gmail.com
* Harden check_func_arg_reg_off check with ARG_PTR_TO_CTX.
* Add tests for unmodified ctx into tail calls.
* Squash unmodified ctx change into base commit.
* Add Reviewed-by's from Emil.
====================
Link: https://patch.msgid.link/20260406194403.1649608-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Ensure we reject programs that access beyond the maximum syscall ctx
size, i.e. U16_MAX either through direct accesses or helpers/kfuncs.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add coverage for unaligned access with fixed offsets and variable
offsets, and through helpers or kfuncs.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Ensure that global subprogs and tail calls can only accept an unmodified
PTR_TO_CTX for syscall programs. For all other program types, fixed or
variable offsets on PTR_TO_CTX is rejected when passed into an argument
of any call instruction type, through the unified logic of
check_func_arg_reg_off.
Finally, add a positive example of a case that should succeed with all
our previous changes.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add various tests to exercise fixed and variable offsets on PTR_TO_CTX
for syscall programs, and cover disallowed cases for other program types
lacking convert_ctx_access callback. Load verifier_ctx with CAP_SYS_ADMIN
so that kfunc related logic can be tested. While at it, convert assembly
tests to C. Unfortunately, ctx_pointer_to_helper_2's unpriv case conflicts
with usage of kfuncs in the file and cannot be run.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Convert existing tests from ASM to C, in prep for future changes to add
more comprehensive tests.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Don't reject usage of fixed unaligned offsets for syscall ctx. Tests
will be added in later commits. Unaligned offsets already work for
variable offsets.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow accessing PTR_TO_CTX with variable offsets in syscall programs.
Fixed offsets are already enabled for all program types that do not
convert their ctx accesses, since the changes we made in the commit
de6c7d99f8 ("bpf: Relax fixed offset check for PTR_TO_CTX"). Note
that we also lift the restriction on passing syscall context into
helpers, which was not permitted before, and passing modified syscall
context into kfuncs.
The structure of check_mem_access can be mostly shared and preserved,
but we must use check_mem_region_access to correctly verify access with
variable offsets.
The check made in check_helper_mem_access is hardened to only allow
PTR_TO_CTX for syscall programs to be passed in as helper memory. This
was the original intention of the existing code anyway, and it makes
little sense for other program types' context to be utilized as a memory
buffer. In case a convincing example presents itself in the future, this
check can be relaxed further.
We also no longer use the last-byte access to simulate helper memory
access, but instead go through check_mem_region_access. Since this no
longer updates our max_ctx_offset, we must do so manually, to keep track
of the maximum offset at which the program ctx may be accessed.
Take care to ensure that when arg_type is ARG_PTR_TO_CTX, we do not
relax any fixed or variable offset constraints around PTR_TO_CTX even in
syscall programs, and require them to be passed unmodified. There are
several reasons why this is necessary. First, if we pass a modified ctx,
then the global subprog's accesses will not update the max_ctx_offset to
its true maximum offset, and can lead to out of bounds accesses. Second,
tail called program (or extension program replacing global subprog) where
their max_ctx_offset exceeds the program they are being called from can
also cause issues. For the latter, unmodified PTR_TO_CTX is the first
requirement for the fix, the second is ensuring max_ctx_offset >= the
program they are being called from, which has to be a separate change
not made in this commit.
All in all, we can hint using arg_type when we expect ARG_PTR_TO_CTX and
make our relaxation around offsets conditional on it.
Drop coverage of syscall tests from verifier_ctx.c temporarily for
negative cases until they are updated in subsequent commits.
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Acked-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260406194403.1649608-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When a dev-bound-only BPF program (BPF_F_XDP_DEV_BOUND_ONLY) undergoes
JIT compilation with constant blinding enabled (bpf_jit_harden >= 2),
bpf_jit_blind_constants() clones the program. The original prog is then
freed in bpf_jit_prog_release_other(), which updates aux->prog to point
to the surviving clone, but fails to update offload->prog.
This leaves offload->prog pointing to the freed original program. When
the network namespace is subsequently destroyed, cleanup_net() triggers
bpf_dev_bound_netdev_unregister(), which iterates ondev->progs and calls
__bpf_prog_offload_destroy(offload->prog). Accessing the freed prog
causes a page fault:
BUG: unable to handle page fault for address: ffffc900085f1038
Workqueue: netns cleanup_net
RIP: 0010:__bpf_prog_offload_destroy+0xc/0x80
Call Trace:
__bpf_offload_dev_netdev_unregister+0x257/0x350
bpf_dev_bound_netdev_unregister+0x4a/0x90
unregister_netdevice_many_notify+0x2a2/0x660
...
cleanup_net+0x21a/0x320
The test sequence that triggers this reliably is:
1. Set net.core.bpf_jit_harden=2 (echo 2 > /proc/sys/net/core/bpf_jit_harden)
2. Run xdp_metadata selftest, which creates a dev-bound-only XDP
program on a veth inside a netns (./test_progs -t xdp_metadata)
3. cleanup_net -> page fault in __bpf_prog_offload_destroy
Dev-bound-only programs are unique in that they have an offload structure
but go through the normal JIT path instead of bpf_prog_offload_compile().
This means they are subject to constant blinding's prog clone-and-replace,
while also having offload->prog that must stay in sync.
Fix this by updating offload->prog in bpf_jit_prog_release_other(),
alongside the existing aux->prog update. Both are back-pointers to
the prog that must be kept in sync when the prog is replaced.
Fixes: 2b3486bc2d ("bpf: Introduce device-bound XDP programs")
Signed-off-by: MingTao Huang <mintaohuang@tencent.com>
Link: https://lore.kernel.org/r/tencent_BCF692F45859CCE6C22B7B0B64827947D406@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tc_tunnel test is based on a send_and_test_data function which takes a
subtest configuration, and a boolean indicating whether the connection
is supposed to fail or not. This boolean is systematically passed to
true, and is a remnant from the first (not integrated) attempts to
convert tc_tunnel to test_progs: those versions validated for
example that a connection properly fails when only one side of the
connection has tunneling enabled. This specific testing has not been
integrated because it involved large timeouts which increased quite a
lot the test duration, for little added value.
Remove the unused boolean from send_and_test_data to simplify the
generic part of subtests.
Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260403-tc_tunnel_cleanup-v1-1-4f1bb113d3ab@bootlin.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Weiming Shi says:
====================
bpf: fix end-of-list detection in cgroup_storage_get_next_key()
list_next_entry() never returns NULL, so the NULL check in
cgroup_storage_get_next_key() is dead code. When iterating past the last
element, the function reads storage->key from a bogus pointer that aliases
internal map fields and copies the result to userspace.
Patch 1 replaces the NULL check with list_entry_is_head() so the function
correctly returns -ENOENT when there are no more entries.
Patch 2 adds a selftest to cover this corner case, as suggested by Sun Jian
and Paul Chaignon.
v2:
- Added selftest (Paul Chaignon)
- Collected Reviewed-by and Acked-by tags
====================
Link: https://patch.msgid.link/20260403132951.43533-1-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Verify that bpf_map__get_next_key() correctly returns -ENOENT when
called on the last (and only) key in a cgroup_storage map. Before the
fix in the previous patch, this would succeed with bogus key data
instead of failing.
Suggested-by: Paul Chaignon <paul.chaignon@gmail.com>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260403132951.43533-3-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
list_next_entry() never returns NULL -- when the current element is the
last entry it wraps to the list head via container_of(). The subsequent
NULL check is therefore dead code and get_next_key() never returns
-ENOENT for the last element, instead reading storage->key from a bogus
pointer that aliases internal map fields and copying the result to
userspace.
Replace it with list_entry_is_head() so the function correctly returns
-ENOENT when there are no more entries.
Fixes: de9cbbaadb ("bpf: introduce cgroup storage maps")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Sun Jian <sun.jian.kdev@gmail.com>
Acked-by: Paul Chaignon <paul.chaignon@gmail.com>
Link: https://lore.kernel.org/r/20260403132951.43533-2-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Mykyta Yatsenko says:
====================
bpf: Fix torn writes in non-prealloc htab with BPF_F_LOCK
A torn write issue was reported in htab_map_update_elem() with
BPF_F_LOCK on hash maps. The BPF_F_LOCK fast path performs
a lockless lookup and copies the value under the element's embedded
spin_lock. A concurrent delete can free the element via
bpf_mem_cache_free(), which allows immediate reuse. When
alloc_htab_elem() recycles the same memory, it writes the value with
plain copy_map_value() without taking the spin_lock, racing with the
stale lock holder and producing torn writes.
Patch 1 fixes alloc_htab_elem() to use copy_map_value_locked() when
BPF_F_LOCK is set.
Patch 2 adds a selftest that reliably detects the torn writes on an
unpatched kernel.
Reported-by: Aaron Esau <aaron1esau@gmail.com>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
====================
Link: https://patch.msgid.link/20260401-bpf_map_torn_writes-v1-0-782d071c55e7@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a consistency subtest to htab_reuse that detects torn writes
caused by the BPF_F_LOCK lockless update racing with element
reallocation in alloc_htab_elem().
The test uses three thread roles started simultaneously via a pipe:
- locked updaters: BPF_F_LOCK|BPF_EXIST in-place updates
- delete+update workers: delete then BPF_ANY|BPF_F_LOCK insert
- locked readers: BPF_F_LOCK lookup checking value consistency
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260401-bpf_map_torn_writes-v1-2-782d071c55e7@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When a BPF_F_LOCK update races with a concurrent delete, the freed
element can be immediately recycled by alloc_htab_elem(). The fast path
in htab_map_update_elem() performs a lockless lookup and then calls
copy_map_value_locked() under the element's spin_lock. If
alloc_htab_elem() recycles the same memory, it overwrites the value
with plain copy_map_value(), without taking the spin_lock, causing
torn writes.
Use copy_map_value_locked() when BPF_F_LOCK is set so the new element's
value is written under the embedded spin_lock, serializing against any
stale lock holders.
Fixes: 96049f3afd ("bpf: introduce BPF_F_LOCK flag")
Reported-by: Aaron Esau <aaron1esau@gmail.com>
Closes: https://lore.kernel.org/all/CADucPGRvSRpkneb94dPP08YkOHgNgBnskTK6myUag_Mkjimihg@mail.gmail.com/
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260401-bpf_map_torn_writes-v1-1-782d071c55e7@meta.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alexei Starovoitov says:
====================
bpf: Prep patches for static stack liveness.
v4->v5:
- minor test fixup
v3->v4:
- fixed invalid recursion detection when calback is called multiple times
v3: https://lore.kernel.org/bpf/20260402212856.86606-1-alexei.starovoitov@gmail.com/
v2->v3:
- added recursive call detection
- fixed ubsan warning
- removed double declaration in the header
- added Acks
v2: https://lore.kernel.org/bpf/20260402061744.10885-1-alexei.starovoitov@gmail.com/
v1->v2:
. fixed bugs spotted by Eduard, Mykyta, claude and gemini
. fixed selftests that were failing in unpriv
. gemini(sashiko) found several precision improvements in patch 6,
but they made no difference in real programs.
v1: https://lore.kernel.org/bpf/20260401021635.34636-1-alexei.starovoitov@gmail.com/
First 6 prep patches for static stack liveness.
. do src/dst_reg validation early and remove defensive checks
. sort subprog in topo order. We wanted to do this long ago
to process global subprogs this way and in other cases.
. Add constant folding pass that computes map_ptr, subprog_idx,
loads from readonly maps, and other constants that fit into 32-bit
. Use these constants to eliminate dead code. Replace predicted
conditional branches with "jmp always". That reduces JIT prog size.
. Add two helpers that return access size from their arguments.
====================
Link: https://patch.msgid.link/20260403024422.87231-1-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The static stack liveness analysis needs to know how many bytes a
helper or kfunc accesses through a stack pointer argument, so it can
precisely mark the affected stack slots as stack 'def' or 'use'.
Add bpf_helper_stack_access_bytes() and bpf_kfunc_stack_access_bytes()
which resolve the access size for a given call argument.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260403024422.87231-7-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add two passes before the main verifier pass:
bpf_compute_const_regs() is a forward dataflow analysis that tracks
register values in R0-R9 across the program using fixed-point
iteration in reverse postorder. Each register is tracked with
a six-state lattice:
UNVISITED -> CONST(val) / MAP_PTR(map_index) /
MAP_VALUE(map_index, offset) / SUBPROG(num) -> UNKNOWN
At merge points, if two paths produce the same state and value for
a register, it stays; otherwise it becomes UNKNOWN.
The analysis handles:
- MOV, ADD, SUB, AND with immediate or register operands
- LD_IMM64 for plain constants, map FDs, map values, and subprogs
- LDX from read-only maps: constant-folds the load by reading the
map value directly via bpf_map_direct_read()
Results that fit in 32 bits are stored per-instruction in
insn_aux_data and bitmasks.
bpf_prune_dead_branches() uses the computed constants to evaluate
conditional branches. When both operands of a conditional jump are
known constants, the branch outcome is determined statically and the
instruction is rewritten to an unconditional jump.
The CFG postorder is then recomputed to reflect new control flow.
This eliminates dead edges so that subsequent liveness analysis
doesn't propagate through dead code.
Also add runtime sanity check to validate that precomputed
constants match the verifier's tracked state.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260403024422.87231-5-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add few tests for topo sort:
- linear chain: main -> A -> B
- diamond: main -> A, main -> B, A -> C, B -> C
- mixed global/static: main -> global -> static leaf
- shared callee: main -> leaf, main -> global -> leaf
- duplicate calls: main calls same subprog twice
- no calls: single subprog
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260403024422.87231-4-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a pass that sorts subprogs in topological order so that iterating
subprog_topo_order[] walks leaf subprogs first, then their callers.
This is computed as a DFS post-order traversal of the CFG.
The pass runs after check_cfg() to ensure the CFG has been validated
before traversing and after postorder has been computed to avoid
walking dead code.
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260403024422.87231-3-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Merge tag 'v7.0-rc6-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client fix from Steve French:
- Fix potential out of bounds read in mount
* tag 'v7.0-rc6-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6:
fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath
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Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Alexei Starovoitov:
- Fix register equivalence for pointers to packet (Alexei Starovoitov)
- Fix incorrect pruning due to atomic fetch precision tracking (Daniel
Borkmann)
- Fix grace period wait for bpf_link-ed tracepoints (Kumar Kartikeya
Dwivedi)
- Fix use-after-free of sockmap's sk->sk_socket (Kuniyuki Iwashima)
- Reject direct access to nullable PTR_TO_BUF pointers (Qi Tang)
- Reject sleepable kprobe_multi programs at attach time (Varun R
Mallya)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: Add more precision tracking tests for atomics
bpf: Fix incorrect pruning due to atomic fetch precision tracking
bpf: Reject sleepable kprobe_multi programs at attach time
bpf: reject direct access to nullable PTR_TO_BUF pointers
bpf: sockmap: Fix use-after-free of sk->sk_socket in sk_psock_verdict_data_ready().
bpf: Fix grace period wait for tracepoint bpf_link
bpf: Fix regsafe() for pointers to packet
Paul Chaignon says:
====================
Fix invariant violations and improve branch detection
This patchset fixes invariant violations on register bounds. These
invariant violations cause a warning and happen when reg_bounds_sync is
trying to refine register bounds while walking an impossible branch.
This patchset takes this situation as an opportunity to improve
verification performance. That is, the verifier will use the invariant
violations as a signal that a branch cannot be taken and process it as
dead code.
This patchset implements this approach and covers it in selftests with
a new invariant violation case. Some of the logic in reg_bounds_sync
likely acts as a duplicate with logic from is_scalar_branch_taken. This
patchset does not attempt to remove superfluous logic from
is_scalar_branch_taken and leaves it to a future patchset (ex. once
syzbot has confirmed that all invariant violations are fixed).
In the future, there is also a potential opportunity to simplify
existing logic by merging reg_bounds_sync and range_bounds_violation
(have reg_bounds_sync error out on invariant violation). That is
however not needed to fix invariant violation, which we focus on in
this patchset.
Changes in v3:
- Rename and refactor the helper functions checking for tnum-related
invariant violations (Mykyta).
- Small changes to comment style in verifier changes and new selftest
(Mykyta).
- Rebased.
Changes in v2:
- Moved tmp registers to env in preparatory commit (Eduard).
- Updated reg_bounds_sync to bail out in case of ill-formed
registers, thus avoiding one set of invariant violation checks in
simulate_both_branches_taken (Eduard).
- Drop the Fixes tag to avoid misleading backporters (Shung-Hsi).
- Improve wording of commit descriptions (Shung-Hsi, Hari).
- Fix error in code comments (AI bot).
- Rebased.
====================
Link: https://patch.msgid.link/cover.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With the changes to the verifier in previous commits, we're not
expecting any invariant violations anymore. We should therefore always
enable BPF_F_TEST_REG_INVARIANTS to fail on invariant violations. Turns
out that's already the case and we've been explicitly setting this flag
in selftests when it wasn't necessary. This commit removes those flags
from selftests, which should hopefully make clearer that it's always
enabled.
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/9afce92510a7d44569dc3af63c9b8c608e69298a.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch adds a selftest for the change in the previous patch. The
selftest is derived from a syzbot reproducer from [1] (among the 22
reproducers on that page, only 4 still reproduced on latest bpf tree,
all being small variants of the same invariant violation).
The test case failure without the previous patch is shown below.
0: R1=ctx() R10=fp0
0: (85) call bpf_get_prandom_u32#7 ; R0=scalar()
1: (bf) r5 = r0 ; R0=scalar(id=1) R5=scalar(id=1)
2: (57) r5 &= -4 ; R5=scalar(smax=0x7ffffffffffffffc,umax=0xfffffffffffffffc,smax32=0x7ffffffc,umax32=0xfffffffc,var_off=(0x0; 0xfffffffffffffffc))
3: (bf) r7 = r0 ; R0=scalar(id=1) R7=scalar(id=1)
4: (57) r7 &= 1 ; R7=scalar(smin=smin32=0,smax=umax=smax32=umax32=1,var_off=(0x0; 0x1))
5: (07) r7 += -43 ; R7=scalar(smin=smin32=-43,smax=smax32=-42,umin=0xffffffffffffffd5,umax=0xffffffffffffffd6,umin32=0xffffffd5,umax32=0xffffffd6,var_off=(0xffffffffffffffd4; 0x3))
6: (5e) if w5 != w7 goto pc+1
verifier bug: REG INVARIANTS VIOLATION (false_reg1): range bounds violation u64=[0xffffffd5, 0xffffffffffffffd4] s64=[0x80000000ffffffd5, 0x7fffffffffffffd4] u32=[0xffffffd5, 0xffffffd4] s32=[0xffffffd5, 0xffffffd4] var_off=(0xffffffd4, 0xffffffff00000000)
R5 and R7 are prepared such that their tnums intersection results in a
known constant but that constant isn't within R7's u32 bounds.
is_branch_taken isn't able to detect this case today, so the verifier
walks the impossible fallthrough branch. After regs_refine_cond_op and
reg_bounds_sync refine R5 on the assumption that the branch is taken,
the impossibility becomes apparent and results in an invariant violation
for R5: umin32 is greater than umax32.
The previous patch fixes this by using regs_refine_cond_op and
reg_bounds_sync in is_branch_taken to detect the impossible branch. The
fallthrough branch is therefore correctly detected as dead code.
Link: https://syzkaller.appspot.com/bug?extid=c950cc277150935cc0b5 [1]
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/b1e22233a3206ead522f02eda27b9c5c991a0de9.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch fixes the invariant violations that can happen after we
refine ranges & tnum based on an incorrectly-detected branch condition.
For example, the branch is always true, but we miss it in
is_branch_taken; we then refine based on the branch being false and end
up with incoherent ranges (e.g. umax < umin).
To avoid this, we can simulate the refinement on both branches. More
specifically, this patch simulates both branches taken using
regs_refine_cond_op and reg_bounds_sync. If the resulting register
states are ill-formed on one of the branches, is_branch_taken can mark
that branch as "never taken".
On a more formal note, we can deduce a branch is not taken when
regs_refine_cond_op or reg_bounds_sync returns an ill-formed state
because the branch operators are sound (verified with Agni [1]).
Soundness means that the verifier is guaranteed to produce sound
outputs on the taken branches. On the non-taken branch (explored
because of imprecision in the bounds), the verifier is free to produce
any output. We use ill-formedness as a signal that the branch is dead
and prune that branch.
This patch moves the refinement logic for both branches from
reg_set_min_max to their own function, simulate_both_branches_taken,
which is called from is_scalar_branch_taken. As a result,
reg_set_min_max now only runs sanity checks and has been renamed to
reg_bounds_sanity_check_branches to reflect that.
We have had five patches fixing specific cases of invariant violations
in the past, all added with selftests:
- commit fbc7aef517 ("bpf: Fix u32/s32 bounds when ranges cross
min/max boundary")
- commit efc11a6678 ("bpf: Improve bounds when tnum has a single
possible value")
- commit f41345f47f ("bpf: Use tnums for JEQ/JNE is_branch_taken
logic")
- commit 00bf8d0c6c ("bpf: Improve bounds when s64 crosses sign
boundary")
- commit 6279846b9b ("bpf: Forget ranges when refining tnum after
JSET")
To confirm that this patch addresses all invariant violations, we have
also reverted those five commits and verified that their related
selftests don't cause any invariant violation warnings anymore. Those
selftests still fail but only because of misdetected branches or
less-precise bounds than expected. This demonstrates that the current
patch is enough to avoid the invariant violation warning AND that the
previous five patches are still useful to improve branch detection.
In addition to the selftests, this change was also tested with the
Cilium complexity test suite: all programs were successfully loaded and
it didn't change the number of processed instructions.
Link: https://github.com/bpfverif/agni [1]
Reported-by: syzbot+c950cc277150935cc0b5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c950cc277150935cc0b5
Co-developed-by: Paul Chaignon <paul.chaignon@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Co-developed-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Signed-off-by: Srinivas Narayana <srinivas.narayana@rutgers.edu>
Co-developed-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Santosh Nagarakatte <santosh.nagarakatte@rutgers.edu>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/a166b54a3cbbbdbcdf8a87f53045f1097176218b.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In the subsequent commit, to prune dead branches we will rely on
detecting ill-formed ranges using range_bounds_violations()
(e.g., umin > umax) after refining register bounds using
regs_refine_cond_op().
However, reg_bounds_sync() can sometimes "repair" ill-formed bounds,
potentially masking a violation that was produced by
regs_refine_cond_op().
This commit modifies reg_bounds_sync() to exit early if an invariant
violation is already present in the input.
This ensures ill-formed reg_states remain ill-formed after
reg_bounds_sync(), allowing simulate_both_branches_taken() to correctly
identify dead branches with a single check to range_bounds_violation().
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/73127d628841c59cb7423d6bdcd204bf90bcdc80.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In a subsequent patch, the regs_refine_cond_op and reg_bounds_sync
functions will be called in is_branch_taken instead of reg_set_min_max,
to simulate each branch's outcome. Since they will run before we branch
out, these two functions will need to work on temporary registers for
the two branches.
This refactoring patch prepares for that change, by introducing the
temporary registers on bpf_verifier_env and using them in
reg_set_min_max.
This change also allows us to save one fake_reg slot as we don't need to
allocate an additional temporary buffer in case of a BPF_K condition.
Finally, you may notice that this patch removes the check for
"false_reg1 == false_reg2" in reg_set_min_max. That check was introduced
in commit d43ad9da80 ("bpf: Skip bounds adjustment for conditional
jumps on same scalar register") to avoid an invariant violation. Given
that "env->false_reg1 == env->false_reg2" doesn't make sense and
invariant violations are addressed in a subsequent commit, this patch
just removes the check.
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Co-developed-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/260b0270052944a420e1c56e6a92df4d43cadf03.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit refactors reg_bounds_sanity_check to factor out the logic
that performs the sanity check from the logic that does the reporting.
Signed-off-by: Harishankar Vishwanathan <harishankar.vishwanathan@gmail.com>
Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/198ec3e69343e2c46dc9cbe2b1bc9be9ae2df5bd.1775142354.git.paul.chaignon@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Add missing async markers to tegra.
- Fix long hmac key DMA handling in caam.
- Fix spurious ENOSPC errors in deflate.
- Fix SG chaining in af_alg.
- Do not use in-place process in algif_aead.
- Fix out-of-place destination overflow in authencesn.
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Merge tag 'v7.0-p4' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
- Add missing async markers to tegra
- Fix long hmac key DMA handling in caam
- Fix spurious ENOSPC errors in deflate
- Fix SG chaining in af_alg
- Do not use in-place process in algif_aead
- Fix out-of-place destination overflow in authencesn
* tag 'v7.0-p4' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption
crypto: algif_aead - Revert to operating out-of-place
crypto: af-alg - fix NULL pointer dereference in scatterwalk
crypto: deflate - fix spurious -ENOSPC
crypto: caam - fix overflow on long hmac keys
crypto: caam - fix DMA corruption on long hmac keys
crypto: tegra - Add missing CRYPTO_ALG_ASYNC
Amery Hung says:
====================
Task local data bug fixes and improvement
This patchset fixed three task local data bugs, improved the
memory allocation code, and dropped unnecessary TLD_READ_ONCE. Please
find the detail in each patch's commit msg.
One thing worth mentioning is that Patch 3 allows us to renable task
local data selftests as the library now always calls aligned_alloc()
with size matching alignment under default configuration.
v1 -> v2
- Fix potential memory leak
- Drop TLD_READ_ONCE()
Link: https://lore.kernel.org/bpf/20260326052437.590158-1-ameryhung@gmail.com/
====================
Link: https://patch.msgid.link/20260331213555.1993883-1-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If TLD_FREE_DATA_ON_THREAD_EXIT is not enabled in a translation unit
that calls __tld_create_key() first, another translation unit that
enables it will not get the auto cleanup feature as pthread key is only
created once when allocation metadata. Fix it by always try to create
the pthread key when __tld_create_key() is called.
Also improve the documentation:
- Discourage user from using different options in different translation
units
- Specify calling tld_free() before thread exit as undefined behavior
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Link: https://lore.kernel.org/r/20260331213555.1993883-6-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
TLD_READ_ONCE() is redundant as the only reference passed to it is
defined as _Atomic. The load is guaranteed to be atomic in C11 standard
(6.2.6.1). Drop the macro.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260331213555.1993883-5-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Without specifying constructor priority of the hidden constructor
function defined by TLD_DEFINE_KEY, __tld_create_key(..., dyn_data =
false) may run after tld_get_data() called from other constructors.
Threads calling tld_get_data() before __tld_create_key(..., dyn_data
= false) will not allocate enough memory for all TLDs and later result
in OOB access. Therefore, set it to the lowest value available to
users. Note that lower means higher priority and 0-100 is reserved to
the compiler.
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260331213555.1993883-4-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Simplify data allocation by always using aligned_alloc() and passing
size_pot, size rounded up to the closest power of two to alignment.
Currently, aligned_alloc(page_size, size) is only intended to be used
with memory allocators that can fulfill the request without rounding
size up to page_size to conserve memory. This is enabled by defining
TLD_DATA_USE_ALIGNED_ALLOC. The reason to align to page_size is due to
the limitation of UPTR where only a page can be pinned to the kernel.
Otherwise, malloc(size * 2) is used to allocate memory for data.
However, we don't need to call aligned_alloc(page_size, size) to get
a contiguous memory of size bytes within a page. aligned_alloc(size_pot,
...) will also do the trick. Therefore, just use aligned_alloc(size_pot,
...) universally.
As for the size argument, create a new option,
TLD_DONT_ROUND_UP_DATA_SIZE, to specify not rounding up the size.
This preserves the current TLD_DATA_USE_ALIGNED_ALLOC behavior, allowing
memory allocators with low overhead aligned_alloc() to not waste memory.
To enable this, users need to make sure it is not an undefined behavior
for the memory allocator to have size not being an integral multiple of
alignment.
Compared to the current implementation, !TLD_DATA_USE_ALIGNED_ALLOC
used to always waste size-byte of memory due to malloc(size * 2).
Now the worst case becomes size - 1 and the best case is 0 when the size
is already a power of two.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Link: https://lore.kernel.org/r/20260331213555.1993883-3-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, when allocating memory for data, size of tld_data_u->start
is not taken into account. This may cause OOB access. Fixed it by adding
the non-flexible array part of tld_data_u.
Besides, explicitly align tld_data_u->data to 8 bytes in case some
fields are added before data in the future. It could break the
assumption that every data field is 8 byte aligned and
sizeof(tld_data_u) will no longer be equal to
offsetof(struct tld_data_u, data), which we use interchangeably.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/r/20260331213555.1993883-2-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Hoyeon Lee says:
====================
libbpf: clarify raw-address single kprobe attach behavior
Today libbpf documents single-kprobe attach through func_name, with an
optional offset. For the PMU-based path, func_name = NULL with an
absolute address in offset already works as well, but that is not
described in the API.
This patchset clarifies this behavior. First commit fixes kprobe
and uprobe attach error handling to use direct error codes. Next adds
kprobe API comments for the raw-address form and rejects it explicitly
for legacy tracefs/debugfs kprobes. Last adds PERF and LINK selftests
for the raw-address form, and checks that LEGACY rejects it.
---
Changes in v7:
- Change selftest line wrapping and assertions
Changes in v6:
- Split the kprobe/uprobe direct error-code fix into a separate patch
Changes in v5:
- Add kprobe API docs, use -EOPNOTSUPP, and switch selftests to LIBBPF_OPTS
Changes in v4:
- Inline raw-address error formatting and remove the probe_target buffer
Changes in v3:
- Drop bpf_kprobe_opts.addr and reuse offset when func_name is NULL
- Make legacy tracefs/debugfs kprobes reject the raw-address form
- Update selftests to cover PERF/LINK raw-address attach and LEGACY reject
Changes in v2:
- Fix line wrapping and indentation
====================
Link: https://patch.msgid.link/20260401143116.185049-1-hoyeon.lee@suse.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Currently, attach_probe covers manual single-kprobe attaches by
func_name, but not the raw-address form that the PMU-based
single-kprobe path can accept.
This commit adds PERF and LINK raw-address coverage. It resolves
SYS_NANOSLEEP_KPROBE_NAME through kallsyms, passes the absolute address
in bpf_kprobe_opts.offset with func_name = NULL, and verifies that
kprobe and kretprobe are still triggered. It also verifies that LEGACY
rejects the same form.
Signed-off-by: Hoyeon Lee <hoyeon.lee@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20260401143116.185049-4-hoyeon.lee@suse.com
bpf_program__attach_kprobe_opts() documents single-kprobe attach
through func_name, with an optional offset. For the PMU-based path,
func_name = NULL with an absolute address in offset already works as
well, but that is not described in the API.
This commit clarifies this existing non-legacy behavior. For PMU-based
attach, callers can use func_name = NULL with an absolute address in
offset as the raw-address form. For legacy tracefs/debugfs kprobes,
reject this form explicitly.
Signed-off-by: Hoyeon Lee <hoyeon.lee@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20260401143116.185049-3-hoyeon.lee@suse.com
perf_event_open_probe() and perf_event_{k,u}probe_open_legacy() helpers
are returning negative error codes directly on failure. This commit
changes bpf_program__attach_{k,u}probe_opts() to use those return
values directly instead of re-reading possibly changed errno.
Signed-off-by: Hoyeon Lee <hoyeon.lee@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20260401143116.185049-2-hoyeon.lee@suse.com
