linux-stable.git/kernel/bpf, branch v6.6.141

bpf: allow UTF-8 literals in bpf_bprintf_prepare()

2026-05-23T11:03:19+00:00

[ Upstream commit b960430ea8862ef37ce53c8bf74a8dc79d3f2404 ]

bpf_bprintf_prepare() only needs ASCII parsing for conversion
specifiers. Plain text can safely carry bytes >= 0x80, so allow
UTF-8 literals outside '%' sequences while keeping ASCII control
bytes rejected and format specifiers ASCII-only.

This keeps existing parsing rules for format directives unchanged,
while allowing helpers such as bpf_trace_printk() to emit UTF-8
literal text.

Update test_snprintf_negative() in the same commit so selftests keep
matching the new plain-text vs format-specifier split during bisection.

Fixes: 48cac3f4a96d ("bpf: Implement formatted output helpers with bstr_printf")
Signed-off-by: Yihan Ding 
Acked-by: Paul Chaignon 
Link: https://lore.kernel.org/r/20260416120142.1420646-2-dingyihan@uniontech.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: Fix NULL deref in map_kptr_match_type for scalar regs

2026-05-23T11:03:19+00:00

[ Upstream commit 4d0a375887ab4d49e4da1ff10f9606cab8f7c3ad ]

Commit ab6c637ad027 ("bpf: Fix a bpf_kptr_xchg() issue with local
kptr") refactored map_kptr_match_type() to branch on btf_is_kernel()
before checking base_type(). A scalar register stored into a kptr
slot has no btf, so the btf_is_kernel(reg->btf) call dereferences
NULL.

Move the base_type() != PTR_TO_BTF_ID guard before any reg->btf
access.

Fixes: ab6c637ad027 ("bpf: Fix a bpf_kptr_xchg() issue with local kptr")
Reported-by: Hiker Cl 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221372
Signed-off-by: Mykyta Yatsenko 
Acked-by: Paul Chaignon 
Link: https://lore.kernel.org/r/20260416-kptr_crash-v1-1-5589356584b4@meta.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: Fix OOB in pcpu_init_value

2026-05-23T11:03:09+00:00

[ Upstream commit 576afddfee8d1108ee299bf10f581593540d1a36 ]

An out-of-bounds read occurs when copying element from a
BPF_MAP_TYPE_CGROUP_STORAGE map to another pcpu map with the
same value_size that is not rounded up to 8 bytes.

The issue happens when:
1. A CGROUP_STORAGE map is created with value_size not aligned to
   8 bytes (e.g., 4 bytes)
2. A pcpu map is created with the same value_size (e.g., 4 bytes)
3. Update element in 2 with data in 1

pcpu_init_value assumes that all sources are rounded up to 8 bytes,
and invokes copy_map_value_long to make a data copy, However, the
assumption doesn't stand since there are some cases where the source
may not be rounded up to 8 bytes, e.g., CGROUP_STORAGE, skb->data.
the verifier verifies exactly the size that the source claims, not
the size rounded up to 8 bytes by kernel, an OOB happens when the
source has only 4 bytes while the copy size(4) is rounded up to 8.

Fixes: d3bec0138bfb ("bpf: Zero-fill re-used per-cpu map element")
Reported-by: Kaiyan Mei 
Closes: https://lore.kernel.org/all/14e6c70c.6c121.19c0399d948.Coremail.kaiyanm@hust.edu.cn/
Link: https://lore.kernel.org/r/420FEEDDC768A4BE+20260402074236.2187154-1-xulang@uniontech.com
Signed-off-by: Lang Xu 
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: Fix RCU stall in bpf_fd_array_map_clear()

2026-05-23T11:03:08+00:00

[ Upstream commit 4406942e65ca128c56c67443832988873c21d2e9 ]

Add a missing cond_resched() in bpf_fd_array_map_clear() loop.

For PROG_ARRAY maps with many entries this loop calls
prog_array_map_poke_run() per entry which can be expensive, and
without yielding this can cause RCU stalls under load:

  rcu: Stack dump where RCU GP kthread last ran:
  CPU: 0 UID: 0 PID: 30932 Comm: kworker/0:2 Not tainted 6.14.0-13195-g967e8def1100 #2 PREEMPT(undef)
  Workqueue: events prog_array_map_clear_deferred
  RIP: 0010:write_comp_data+0x38/0x90 kernel/kcov.c:246
  Call Trace:
   
   prog_array_map_poke_run+0x77/0x380 kernel/bpf/arraymap.c:1096
   __fd_array_map_delete_elem+0x197/0x310 kernel/bpf/arraymap.c:925
   bpf_fd_array_map_clear kernel/bpf/arraymap.c:1000 [inline]
   prog_array_map_clear_deferred+0x119/0x1b0 kernel/bpf/arraymap.c:1141
   process_one_work+0x898/0x19d0 kernel/workqueue.c:3238
   process_scheduled_works kernel/workqueue.c:3319 [inline]
   worker_thread+0x770/0x10b0 kernel/workqueue.c:3400
   kthread+0x465/0x880 kernel/kthread.c:464
   ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153
   ret_from_fork_asm+0x19/0x30 arch/x86/entry/entry_64.S:245
   

Reviewed-by: Sun Jian 
Fixes: da765a2f5993 ("bpf: Add poke dependency tracking for prog array maps")
Signed-off-by: Sechang Lim 
Link: https://lore.kernel.org/r/20260407103823.3942156-1-rhkrqnwk98@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: Drop task_to_inode and inet_conn_established from lsm sleepable hooks

2026-05-23T11:03:07+00:00

[ Upstream commit beaf0e96b1da74549a6cabd040f9667d83b2e97e ]

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: 423f16108c9d8 ("bpf: Augment the set of sleepable LSM hooks")
Reported-by: Quan Sun <2022090917019@std.uestc.edu.cn>
Reported-by: Yinhao Hu 
Reported-by: Kaiyan Mei 
Reported-by: Dongliang Mu 
Closes: https://lore.kernel.org/bpf/3ab69731-24d1-431a-a351-452aafaaf2a5@std.uestc.edu.cn/T/#u
Signed-off-by: Jiayuan Chen 
Link: https://lore.kernel.org/r/20260407122334.344072-1-jiayuan.chen@linux.dev
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: Fix stale offload->prog pointer after constant blinding

2026-05-23T11:03:07+00:00

[ Upstream commit a1aa9ef47c299c5bbc30594d3c2f0589edf908e6 ]

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: 2b3486bc2d23 ("bpf: Introduce device-bound XDP programs")
Signed-off-by: MingTao Huang 
Link: https://lore.kernel.org/r/tencent_BCF692F45859CCE6C22B7B0B64827947D406@qq.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: fix end-of-list detection in cgroup_storage_get_next_key()

2026-05-23T11:03:07+00:00

[ Upstream commit 5828b9e5b272ecff7cf5d345128d3de7324117f7 ]

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: de9cbbaadba5 ("bpf: introduce cgroup storage maps")
Reported-by: Xiang Mei 
Signed-off-by: Weiming Shi 
Reviewed-by: Sun Jian 
Acked-by: Paul Chaignon 
Link: https://lore.kernel.org/r/20260403132951.43533-2-bestswngs@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path

2026-05-23T11:03:07+00:00

[ Upstream commit 8ed82f807bb09d2c8455aaa665f2c6cb17bc6a19 ]

The DEVMAP_HASH branch in dev_map_redirect_multi() uses
hlist_for_each_entry_safe() to iterate hash buckets, but this function
runs under RCU protection (called from xdp_do_generic_redirect_map()
in softirq context). Concurrent writers (__dev_map_hash_update_elem,
dev_map_hash_delete_elem) modify the list using RCU primitives
(hlist_add_head_rcu, hlist_del_rcu).

hlist_for_each_entry_safe() performs plain pointer dereferences without
rcu_dereference(), missing the acquire barrier needed to pair with
writers' rcu_assign_pointer(). On weakly-ordered architectures (ARM64,
POWER), a reader can observe a partially-constructed node. It also
defeats CONFIG_PROVE_RCU lockdep validation and KCSAN data-race
detection.

Replace with hlist_for_each_entry_rcu() using rcu_read_lock_bh_held()
as the lockdep condition, consistent with the rcu_dereference_check()
used in the DEVMAP (non-hash) branch of the same functions. Also fix
the same incorrect lockdep_is_held(&dtab->index_lock) condition in
dev_map_enqueue_multi(), where the lock is not held either.

Fixes: e624d4ed4aa8 ("xdp: Extend xdp_redirect_map with broadcast support")
Signed-off-by: David Carlier 
Signed-off-by: Martin KaFai Lau 
Link: https://patch.msgid.link/20260320072645.16731-1-devnexen@gmail.com
Signed-off-by: Sasha Levin

bpf, devmap: Remove unnecessary if check in for loop

2026-05-23T11:03:07+00:00

[ Upstream commit 2317dc2c22cc353b699c7d1db47b2fe91f54055c ]

The iterator variable dst cannot be NULL and the if check can be removed.
Remove it and fix the following Coccinelle/coccicheck warning reported
by itnull.cocci:

	ERROR: iterator variable bound on line 762 cannot be NULL

Signed-off-by: Thorsten Blum 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Toke Høiland-Jørgensen 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/20240529101900.103913-2-thorsten.blum@toblux.com
Stable-dep-of: 8ed82f807bb0 ("bpf: Use RCU-safe iteration in dev_map_redirect_multi() SKB path")
Signed-off-by: Sasha Levin

bpf: Don't mark STACK_INVALID as STACK_MISC in mark_stack_slot_misc

2026-05-17T15:13:36+00:00

[ Upstream commit 69772f509e084ec6bca12dbcdeeeff41b0103774 ]

Inside mark_stack_slot_misc, we should not upgrade STACK_INVALID to
STACK_MISC when allow_ptr_leaks is false, since invalid contents
shouldn't be read unless the program has the relevant capabilities.
The relaxation only makes sense when env->allow_ptr_leaks is true.

However, such conversion in privileged mode becomes unnecessary, as
invalid slots can be read without being upgraded to STACK_MISC.

Currently, the condition is inverted (i.e. checking for true instead of
false), simply remove it to restore correct behavior.

Fixes: eaf18febd6eb ("bpf: preserve STACK_ZERO slots on partial reg spills")
Acked-by: Andrii Nakryiko 
Reported-by: Tao Lyu 
Signed-off-by: Kumar Kartikeya Dwivedi 
Link: https://lore.kernel.org/r/20241204044757.1483141-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin