linux.git/kernel/bpf/cgroup.c, branch v6.19.12

bpf: Convert bpf_sock_addr_kern "uaddr" to sockaddr_unsized

2025-11-05T03:10:33+00:00

Change struct bpf_sock_addr_kern to use sockaddr_unsized for the "uaddr"
field instead of sockaddr. This improves type safety in the BPF cgroup
socket address filtering code.

The casting in __cgroup_bpf_run_filter_sock_addr() is updated to match the
new type, removing an unnecessary cast in the initialization and updating
the conditional assignment to use the appropriate sockaddr_unsized cast.

Additionally rename the "unspec" variable to "storage" to better align
with its usage.

No binary changes expected.

Signed-off-by: Kees Cook 
Link: https://patch.msgid.link/20251104002617.2752303-7-kees@kernel.org
Signed-off-by: Jakub Kicinski

bpf: Convert cgroup sockaddr filters to use sockaddr_unsized consistently

2025-11-05T03:10:33+00:00

Update BPF cgroup sockaddr filtering infrastructure to use sockaddr_unsized
consistently throughout the call chain, removing redundant explicit casts
from callers.

No binary changes expected.

Signed-off-by: Kees Cook 
Link: https://patch.msgid.link/20251104002617.2752303-6-kees@kernel.org
Signed-off-by: Jakub Kicinski

bpf: WQ_PERCPU added to alloc_workqueue users

2025-09-08T17:04:37+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.

alloc_workqueue() treats all queues as per-CPU by default, while unbound
workqueues must opt-in via WQ_UNBOUND.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This default is suboptimal: most workloads benefit from unbound queues,
allowing the scheduler to place worker threads where they’re needed and
reducing noise when CPUs are isolated.

This patch adds a new WQ_PERCPU flag to explicitly request the use of
the per-CPU behavior. Both flags coexist for one release cycle to allow
callers to transition their calls.

Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU.

All existing users have been updated accordingly.

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Link: https://lore.kernel.org/r/20250905085309.94596-4-marco.crivellari@suse.com
Signed-off-by: Alexei Starovoitov

bpf: replace use of system_wq with system_percpu_wq

2025-09-08T17:04:37+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.

This lack of consistentcy cannot be addressed without refactoring the API.

system_wq is a per-CPU worqueue, yet nothing in its name tells about that
CPU affinity constraint, which is very often not required by users. Make
it clear by adding a system_percpu_wq.

queue_work() / queue_delayed_work() mod_delayed_work() will now use the
new per-cpu wq: whether the user still stick on the old name a warn will
be printed along a wq redirect to the new one.

This patch add the new system_percpu_wq except for mm, fs and net
subsystem, whom are handled in separated patches.

The old wq will be kept for a few release cylces.

Suggested-by: Tejun Heo 
Signed-off-by: Marco Crivellari 
Link: https://lore.kernel.org/r/20250905085309.94596-2-marco.crivellari@suse.com
Signed-off-by: Alexei Starovoitov

bpf: use rcu_read_lock_dont_migrate() for bpf_prog_run_array_cg()

2025-08-26T01:52:16+00:00

Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_prog_run_array_cg to obtain better performance when PREEMPT_RCU is
not enabled.

Signed-off-by: Menglong Dong 
Link: https://lore.kernel.org/r/20250821090609.42508-7-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov

Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-07-30T16:58:50+00:00

Pull bpf updates from Alexei Starovoitov:

 - Remove usermode driver (UMD) framework (Thomas Weißschuh)

 - Introduce Strongly Connected Component (SCC) in the verifier to
   detect loops and refine register liveness (Eduard Zingerman)

 - Allow 'void *' cast using bpf_rdonly_cast() and corresponding
   '__arg_untrusted' for global function parameters (Eduard Zingerman)

 - Improve precision for BPF_ADD and BPF_SUB operations in the verifier
   (Harishankar Vishwanathan)

 - Teach the verifier that constant pointer to a map cannot be NULL
   (Ihor Solodrai)

 - Introduce BPF streams for error reporting of various conditions
   detected by BPF runtime (Kumar Kartikeya Dwivedi)

 - Teach the verifier to insert runtime speculation barrier (lfence on
   x86) to mitigate speculative execution instead of rejecting the
   programs (Luis Gerhorst)

 - Various improvements for 'veristat' (Mykyta Yatsenko)

 - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
   improve bug detection by syzbot (Paul Chaignon)

 - Support BPF private stack on arm64 (Puranjay Mohan)

 - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
   node (Song Liu)

 - Introduce kfuncs for read-only string opreations (Viktor Malik)

 - Implement show_fdinfo() for bpf_links (Tao Chen)

 - Reduce verifier's stack consumption (Yonghong Song)

 - Implement mprog API for cgroup-bpf programs (Yonghong Song)

* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
  selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
  selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
  bpf: Add log for attaching tracing programs to functions in deny list
  bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
  bpf: Fix various typos in verifier.c comments
  bpf: Add third round of bounds deduction
  selftests/bpf: Test invariants on JSLT crossing sign
  selftests/bpf: Test cross-sign 64bits range refinement
  selftests/bpf: Update reg_bound range refinement logic
  bpf: Improve bounds when s64 crosses sign boundary
  bpf: Simplify bounds refinement from s32
  selftests/bpf: Enable private stack tests for arm64
  bpf, arm64: JIT support for private stack
  bpf: Move bpf_jit_get_prog_name() to core.c
  bpf, arm64: Fix fp initialization for exception boundary
  umd: Remove usermode driver framework
  bpf/preload: Don't select USERMODE_DRIVER
  selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
  selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
  selftests/bpf: Increase xdp data size for arm64 64K page size
  ...

bpf: Reject narrower access to pointer ctx fields

2025-07-24T02:33:49+00:00

The following BPF program, simplified from a syzkaller repro, causes a
kernel warning:

    r0 = *(u8 *)(r1 + 169);
    exit;

With pointer field sk being at offset 168 in __sk_buff. This access is
detected as a narrower read in bpf_skb_is_valid_access because it
doesn't match offsetof(struct __sk_buff, sk). It is therefore allowed
and later proceeds to bpf_convert_ctx_access. Note that for the
"is_narrower_load" case in the convert_ctx_accesses(), the insn->off
is aligned, so the cnt may not be 0 because it matches the
offsetof(struct __sk_buff, sk) in the bpf_convert_ctx_access. However,
the target_size stays 0 and the verifier errors with a kernel warning:

    verifier bug: error during ctx access conversion(1)

This patch fixes that to return a proper "invalid bpf_context access
off=X size=Y" error on the load instruction.

The same issue affects multiple other fields in context structures that
allow narrow access. Some other non-affected fields (for sk_msg,
sk_lookup, and sockopt) were also changed to use bpf_ctx_range_ptr for
consistency.

Note this syzkaller crash was reported in the "Closes" link below, which
used to be about a different bug, fixed in
commit fce7bd8e385a ("bpf/verifier: Handle BPF_LOAD_ACQ instructions
in insn_def_regno()"). Because syzbot somehow confused the two bugs,
the new crash and repro didn't get reported to the mailing list.

Fixes: f96da09473b52 ("bpf: simplify narrower ctx access")
Fixes: 0df1a55afa832 ("bpf: Warn on internal verifier errors")
Reported-by: syzbot+0ef84a7bdf5301d4cbec@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0ef84a7bdf5301d4cbec
Signed-off-by: Paul Chaignon 
Signed-off-by: Martin KaFai Lau 
Acked-by: Eduard Zingerman 
Link: https://patch.msgid.link/3b8dcee67ff4296903351a974ddd9c4dca768b64.1753194596.git.paul.chaignon@gmail.com

bpf: Use ERR_CAST instead of ERR_PTR(PTR_ERR(...))

2025-07-22T00:27:09+00:00

Intel linux test robot reported a warning that ERR_CAST can be used
for error pointer casting instead of more-complicated/rarely-used
ERR_PTR(PTR_ERR(...)) style.

There is no functionality change, but still let us replace two such
instances as it improves consistency and readability.

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202507201048.bceHy8zX-lkp@intel.com/
Signed-off-by: Yonghong Song 
Signed-off-by: Martin KaFai Lau 
Acked-by: Eduard Zingerman 
Link: https://patch.msgid.link/20250720164754.3999140-1-yonghong.song@linux.dev

bpf: Remove attach_type in bpf_cgroup_link

2025-07-11T17:51:55+00:00

Use attach_type in bpf_link, and remove it in bpf_cgroup_link.

Signed-off-by: Tao Chen 
Signed-off-by: Andrii Nakryiko 
Acked-by: Daniel Borkmann 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/20250710032038.888700-3-chen.dylane@linux.dev

bpf: Add attach_type field to bpf_link

2025-07-11T17:51:55+00:00

Attach_type will be set when a link is created by user. It is better to
record attach_type in bpf_link generically and have it available
universally for all link types. So add the attach_type field in bpf_link
and move the sleepable field to avoid unnecessary gap padding.

Signed-off-by: Tao Chen 
Signed-off-by: Andrii Nakryiko 
Acked-by: Daniel Borkmann 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/20250710032038.888700-2-chen.dylane@linux.dev