linux.git/kernel/bpf/helpers.c, branch v7.3-rc2

bpf: Fix arm64 KASAN false positive after bpf_throw

2026-08-14T16:26:14+00:00

arm64 passes zero as the stack pointer while walking BPF frames, so
bpf_throw() leaves stale KASAN stack poison after jumping to the
exception callback.

Use the frame pointer as the fallback stack watermark.

Fixes: e74cb1b42213 ("arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT")
Signed-off-by: Mykyta Yatsenko 
Signed-off-by: Daniel Borkmann 
Tested-by: Ihor Solodrai 
Link: https://lore.kernel.org/bpf/20260812-hello_world-v1-1-c3c2ddcb362d@meta.com

bpf: Drop duplicate blank lines in kernel/bpf/

2026-08-13T17:27:40+00:00

There are many adjacent blank lines in kernel/bpf/ that have accumulated
over time.

Drop them for cleanup.

No functional changes intended.

Signed-off-by: Leon Hwang 
Signed-off-by: Andrii Nakryiko 
Reviewed-by: Emil Tsalapatis 
Link: https://lore.kernel.org/bpf/20260813152324.97937-2-leon.hwang@linux.dev

bpf: Mark existing lock-safe kfuncs with KF_SPINLOCK_SAFE

2026-08-06T08:58:04+00:00

The verifier currently keeps a hard-coded list of kfuncs that may be
called while holding a bpf_spin_lock. With KF_SPINLOCK_SAFE available,
retaining this list creates two sources of truth and requires verifier
changes whenever another lock-safe kfunc is added.

Mark every kfunc currently accepted by kfunc_spin_allowed() with
KF_SPINLOCK_SAFE. This covers the graph, numeric iterator, resource
spin lock, arena, and stream kfuncs.

Remove the obsolete category checks and make kfunc_spin_allowed() rely
solely on the kfunc registration metadata. This preserves the behavior
of existing kfuncs while using the same mechanism for built-in and
module kfuncs.

Signed-off-by: Kaitao Cheng 
Acked-by: Leon Hwang 
Link: https://lore.kernel.org/bpf/20260805153340.34776-3-kaitao.cheng@linux.dev
Signed-off-by: Kumar Kartikeya Dwivedi

bpf: Rename ARG_CONST_SIZE{,_OR_ZERO} to ARG_MEM_SIZE{,_OR_ZERO}

2026-08-02T22:29:14+00:00

ARG_CONST_SIZE does not require a constant: check_mem_size_reg() accepts
any bounded scalar and verifies the memory access against its maximum
(reg_umax). Rename ARG_CONST_SIZE and ARG_CONST_SIZE_OR_ZERO to
ARG_MEM_SIZE and ARG_MEM_SIZE_OR_ZERO to reflect that. ARG_CONST_ALLOC_
SIZE_OR_ZERO, which does require a constant, is left unchanged.

Pure rename, no functional change.

Signed-off-by: Amery Hung 
Link: https://lore.kernel.org/bpf/20260801074633.1595644-10-ameryhung@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi

bpf: Split kfunc map argument into __const_map and __map

2026-08-02T22:29:11+00:00

Kfuncs used a single '__map' suffix (KF_ARG_PTR_TO_MAP) for two different
things: a verifier-known map matched by map_uid against a bound
timer/wq/task_work object (bpf_wq_init, bpf_task_work_schedule*), and an
opaque 'struct bpf_map *' used only at runtime (bpf_arena_*), which may be a
map fd or a PTR_TO_BTF_ID struct bpf_map (e.g. a bpf_map iterator's ctx->map).

That combined path only accepted the btf map form due to type confusion. The
'if (!reg->map_ptr)' check reads reg->map_ptr, which aliases reg->btf in the
bpf_reg_state union. A PTR_TO_BTF_ID register always has a non-NULL reg->btf,
so the guard silently passed and validation fell through to
process_kf_arg_ptr_to_btf_id(). It also recorded PTR_TO_BTF_ID info in
meta->map, which would be meaningless.

Split the annotation to avoid such type confusion and to align with
helper:

- '__const_map' -> KF_ARG_CONST_MAP_PTR: verifier-known map, handled by
  process_map_ptr_arg() like helper ARG_CONST_MAP_PTR.

- '__map' -> KF_ARG_PTR_TO_BTF_ID: opaque struct bpf_map, validated by
  process_kf_arg_ptr_to_btf_id(). A map fd still matches via
  reg2btf_ids[CONST_PTR_TO_MAP], so bpf_arena_alloc_pages(&map) keeps
  working.

Signed-off-by: Amery Hung 
Reviewed-by: Eduard Zingerman 
Link: https://lore.kernel.org/bpf/20260801074633.1595644-4-ameryhung@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi

bpf: Fix CFI mismatch in task work callback

2026-07-24T20:23:17+00:00

BPF subprograms use the bpf_callback_t ABI, but task work invokes the
callback through a three-argument function pointer. This trips kCFI.

Store and invoke the callback as bpf_callback_t.

Fixes: 38aa7003e369 ("bpf: task work scheduling kfuncs")
Signed-off-by: Mykyta Yatsenko 
Link: https://lore.kernel.org/bpf/20260724-task_work_cfi-v1-1-2616691781ed@meta.com
Signed-off-by: Kumar Kartikeya Dwivedi

Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-06-21T20:20:19+00:00

Pull non-MM updates from Andrew Morton:

 - "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)

   Fix a taskstats TGID aggregation bug where fields added in the TGID
   query path were not preserved after thread exit, and adds a kselftest
   covering the regression.

 - "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)

   Improve lib/tests/string_helpers_kunit.c a little

 - "lib/base64: decode fixes" (Josh Law)

   Address minor issues in lib/base64.c

 - "selftests/filelock: Make output more kselftestish" (Mark Brown)

   Make the output from the ofdlocks test a bit easier for tooling to
   work with. Also ignore the generated file

 - "uaccess: unify inline vs outline copy_{from,to}_user() selection"
   (Yury Norov)

   Simplify the usercopy code by removing the selectability of inlining
   copy_{from,to}_user().

 - "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)

   Fix a number of possible issues in the ocfs2 xattr code

 - "lib and lib/cmdline enhancements" (Dmitry Antipov)

   Provide additional robustness checking in the cmdline handling code
   and its in-kernel testing and selftests

 - "cleanup the RAID6 P/Q library" (Christoph Hellwig)

   Clean up the RAID6 P/Q library to match the recent updates to the
   RAID 5 XOR library and other CRC/crypto libraries

 - "ocfs2: harden inode validators against forged metadata" (Michael
   Bommarito)

   Add three structural checks to OCFS2 dinode validation so malformed
   on-disk fields are rejected before ocfs2_populate_inode() copies them
   into the in-core inode

 - "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
   Rapoport)

   Clean up the lib/raid code by using kmalloc() in more places

* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
  ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
  ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
  lib: interval_tree_test: validate benchmark parameters
  ocfs2: avoid moving extents to occupied clusters
  treewide: fix transposed "sign" typos and update spelling.txt
  ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
  fat: reject BPB volumes whose data area starts beyond total sectors
  selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
  lib/test_firmware: allocate the configured into_buf size
  fs: efs: remove unneeded debug prints
  checkpatch: cuppress warnings when Reported-by: is followed by Link:
  MAINTAINERS: add Alexander as a kcov reviewer
  mailmap: update Alexander Sverdlin's Email addresses
  fs: fat: inode: replace sprintf() with scnprintf()
  ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
  ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
  ocfs2/dlm: require a ref for locking_state debugfs open
  ocfs2: reject FITRIM ranges shorter than a cluster
  ocfs2: validate fast symlink target during inode read
  ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
  ...

treewide: fix transposed "sign" typos and update spelling.txt

2026-06-17T22:37:47+00:00

Several comments transpose the letters in "assigned" and "unsigned",
spelling them with "sing" instead of "sign".  Correct all of them.

Of these, the misspelling of "assigned" is not yet flagged by checkpatch,
so also add it to scripts/spelling.txt.

The remaining matches of `grep -ri singed` are RISINGEDGE register and
enum names, not typos.

Link: https://lore.kernel.org/20260612181633.734458-1-iamsharduld@gmail.com
Signed-off-by: Shardul Deshpande 
Suggested-by: Andrew Morton 
Reviewed-by: SeongJae Park 
Cc: Joe Perches 
Signed-off-by: Andrew Morton

bpf: Fix NULL pointer dereference in bpf_task_from_vpid()

2026-06-08T11:33:55+00:00

bpf_task_from_vpid() looks up a task in the pid namespace of the
current task, via find_task_by_vpid():

  find_task_by_vpid(vpid)
    find_task_by_pid_ns(vpid, task_active_pid_ns(current))
      find_pid_ns(nr, ns) -> idr_find(&ns->idr, nr)

cgroup_skb programs run in softirq, which may interrupt a task that is
itself in do_exit(). Once that task has passed
exit_notify() -> release_task() -> __unhash_process(), its thread_pid is
cleared, so task_active_pid_ns(current) returns NULL and find_pid_ns()
dereferences &NULL->idr:

  BUG: kernel NULL pointer dereference, address: 0000000000000050
  RIP: 0010:idr_find+0x11/0x30 lib/idr.c:176
  Call Trace:
   
   find_pid_ns kernel/pid.c:370 [inline]
   find_task_by_pid_ns+0x3b/0xe0 kernel/pid.c:485
   bpf_task_from_vpid+0x5b/0x200 kernel/bpf/helpers.c:2916
   bpf_prog_run_array_cg+0x17e/0x530 kernel/bpf/cgroup.c:81
   __cgroup_bpf_run_filter_skb+0x12b/0x250 kernel/bpf/cgroup.c:1612
   sk_filter_trim_cap+0x1dc/0x4c0 net/core/filter.c:148
   tcp_v4_rcv+0x18d1/0x2200 net/ipv4/tcp_ipv4.c:2223
   
   
   do_exit+0xa63/0x1270 kernel/exit.c:1010
   get_signal+0x141c/0x1530 kernel/signal.c:3037

Bail out when current has no pid namespace.

Fixes: 675c3596ff32 ("bpf: Add bpf_task_from_vpid() kfunc")
Signed-off-by: Sechang Lim 
Acked-by: Leon Hwang 
Link: https://lore.kernel.org/bpf/20260608050001.2545245-1-rhkrqnwk98@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi

bpf: Clear rb node linkage when freeing bpf_rb_root

2026-06-05T21:19:19+00:00

bpf_rb_root_free() detaches the root by copying the current rb_root_cached
and then replacing the live root with RB_ROOT_CACHED. It then walks the
copied root and drops each object contained in the tree.

This leaves the rb node state intact while dropping the object. If the
object is refcounted and survives the drop, its bpf_rb_node_kern still
contains an owner pointer to the freed root and stale rb tree linkage. If
a later bpf_rb_root allocation reuses the same address, bpf_rbtree_remove()
can incorrectly pass the owner check and call rb_erase_cached() on a node
whose rb pointers belong to the old tree.

Mirror the list draining behavior by marking nodes as busy while the root
is being detached, then clear the rb node and release the owner before
dropping the containing object. This makes surviving nodes unowned and
safe to reject from remove or accept for a later add.

Fixes: 9c395c1b99bd ("bpf: Add basic bpf_rb_{root,node} support")
Signed-off-by: Kaitao Cheng 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/r/20260605094143.5509-1-kaitao.cheng@linux.dev
Signed-off-by: Alexei Starovoitov