wireguard-linux/kernel/bpf, branch stable

bpf: Conditionally include dynptr copy kfuncs

2025-10-24T16:44:47Z

Since commit a498ee7576de ("bpf: Implement dynptr copy kfuncs"), if CONFIG_BPF_EVENTS is not enabled, but BPF_SYSCALL and DEBUG_INFO_BTF are, the build will break like so: BTFIDS vmlinux.unstripped WARN: resolve_btfids: unresolved symbol bpf_probe_read_user_str_dynptr WARN: resolve_btfids: unresolved symbol bpf_probe_read_user_dynptr WARN: resolve_btfids: unresolved symbol bpf_probe_read_kernel_str_dynptr WARN: resolve_btfids: unresolved symbol bpf_probe_read_kernel_dynptr WARN: resolve_btfids: unresolved symbol bpf_copy_from_user_task_str_dynptr WARN: resolve_btfids: unresolved symbol bpf_copy_from_user_task_dynptr WARN: resolve_btfids: unresolved symbol bpf_copy_from_user_str_dynptr WARN: resolve_btfids: unresolved symbol bpf_copy_from_user_dynptr make[2]: *** [scripts/Makefile.vmlinux:72: vmlinux.unstripped] Error 255 make[2]: *** Deleting file 'vmlinux.unstripped' make[1]: *** [/repo/malin/upstream/linux/Makefile:1242: vmlinux] Error 2 make: *** [Makefile:248: __sub-make] Error 2 Guard these symbols with #ifdef CONFIG_BPF_EVENTS to resolve the problem. Fixes: a498ee7576de ("bpf: Implement dynptr copy kfuncs") Reported-by: Yong Gu Acked-by: Mykyta Yatsenko Signed-off-by: Malin Jonsson Link: https://lore.kernel.org/r/20251024151436.139131-1-malin.jonsson@est.tech Signed-off-by: Alexei Starovoitov

bpf: Sync pending IRQ work before freeing ring buffer

2025-10-21T16:57:48Z

Fix a race where irq_work can be queued in bpf_ringbuf_commit() but the ring buffer is freed before the work executes. In the syzbot reproducer, a BPF program attached to sched_switch triggers bpf_ringbuf_commit(), queuing an irq_work. If the ring buffer is freed before this work executes, the irq_work thread may accesses freed memory. Calling `irq_work_sync(&rb->work)` ensures that all pending irq_work complete before freeing the buffer. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Reported-by: syzbot+2617fc732430968b45d2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2617fc732430968b45d2 Tested-by: syzbot+2617fc732430968b45d2@syzkaller.appspotmail.com Signed-off-by: Noorain Eqbal Link: https://lore.kernel.org/r/20251020180301.103366-1-nooraineqbal@gmail.com Signed-off-by: Alexei Starovoitov

bpf: Fix memory leak in __lookup_instance error path

2025-10-16T17:45:17Z

When __lookup_instance() allocates a func_instance structure but fails to allocate the must_write_set array, it returns an error without freeing the previously allocated func_instance. This causes a memory leak of 192 bytes (sizeof(struct func_instance)) each time this error path is triggered. Fix by freeing 'result' on must_write_set allocation failure. Fixes: b3698c356ad9 ("bpf: callchain sensitive stack liveness tracking using CFG") Reported-by: BPF Runtime Fuzzer (BRF) Signed-off-by: Shardul Bankar Signed-off-by: Martin KaFai Lau Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20251016063330.4107547-1-shardulsb08@gmail.com

bpf: Replace bpf_map_kmalloc_node() with kmalloc_nolock() to allocate bpf_async_cb structures.

2025-10-15T10:22:22Z

The following kmemleak splat: [ 8.105530] kmemleak: Trying to color unknown object at 0xff11000100e918c0 as Black [ 8.106521] Call Trace: [ 8.106521] [ 8.106521] dump_stack_lvl+0x4b/0x70 [ 8.106521] kvfree_call_rcu+0xcb/0x3b0 [ 8.106521] ? hrtimer_cancel+0x21/0x40 [ 8.106521] bpf_obj_free_fields+0x193/0x200 [ 8.106521] htab_map_update_elem+0x29c/0x410 [ 8.106521] bpf_prog_cfc8cd0f42c04044_overwrite_cb+0x47/0x4b [ 8.106521] bpf_prog_8c30cd7c4db2e963_overwrite_timer+0x65/0x86 [ 8.106521] bpf_prog_test_run_syscall+0xe1/0x2a0 happens due to the combination of features and fixes, but mainly due to commit 6d78b4473cdb ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()") It's using __GFP_HIGH, which instructs slub/kmemleak internals to skip kmemleak_alloc_recursive() on allocation, so subsequent kfree_rcu()-> kvfree_call_rcu()->kmemleak_ignore() complains with the above splat. To fix this imbalance, replace bpf_map_kmalloc_node() with kmalloc_nolock() and kfree_rcu() with call_rcu() + kfree_nolock() to make sure that the objects allocated with kmalloc_nolock() are freed with kfree_nolock() rather than the implicit kfree() that kfree_rcu() uses internally. Note, the kmalloc_nolock() happens under bpf_spin_lock_irqsave(), so it will always fail in PREEMPT_RT. This is not an issue at the moment, since bpf_timers are disabled in PREEMPT_RT. In the future bpf_spin_lock will be replaced with state machine similar to bpf_task_work. Fixes: 6d78b4473cdb ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()") Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Reviewed-by: Shakeel Butt Acked-by: Harry Yoo Acked-by: Vlastimil Babka Cc: linux-mm@kvack.org Link: https://lore.kernel.org/bpf/20251015000700.28988-1-alexei.starovoitov@gmail.com

bpf: Avoid RCU context warning when unpinning htab with internal structs

2025-10-10T17:10:08Z

When unpinning a BPF hash table (htab or htab_lru) that contains internal structures (timer, workqueue, or task_work) in its values, a BUG warning is triggered: BUG: sleeping function called from invalid context at kernel/bpf/hashtab.c:244 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 14, name: ksoftirqd/0 ... The issue arises from the interaction between BPF object unpinning and RCU callback mechanisms: 1. BPF object unpinning uses ->free_inode() which schedules cleanup via call_rcu(), deferring the actual freeing to an RCU callback that executes within the RCU_SOFTIRQ context. 2. During cleanup of hash tables containing internal structures, htab_map_free_internal_structs() is invoked, which includes cond_resched() or cond_resched_rcu() calls to yield the CPU during potentially long operations. However, cond_resched() or cond_resched_rcu() cannot be safely called from atomic RCU softirq context, leading to the BUG warning when attempting to reschedule. Fix this by changing from ->free_inode() to ->destroy_inode() and rename bpf_free_inode() to bpf_destroy_inode() for BPF objects (prog, map, link). This allows direct inode freeing without RCU callback scheduling, avoiding the invalid context warning. Reported-by: Le Chen Closes: https://lore.kernel.org/all/1444123482.1827743.1750996347470.JavaMail.zimbra@sjtu.edu.cn/ Fixes: 68134668c17f ("bpf: Add map side support for bpf timers.") Suggested-by: Alexei Starovoitov Signed-off-by: KaFai Wan Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20251008102628.808045-2-kafai.wan@linux.dev Signed-off-by: Alexei Starovoitov

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

2025-10-04T02:38:19Z

Pull bpf fixes from Alexei Starovoitov: - Fix selftests/bpf (typo, conflicts) and unbreak BPF CI (Jiri Olsa) - Remove linux/unaligned.h dependency for libbpf_sha256 (Andrii Nakryiko) and add a test (Eric Biggers) - Reject negative offsets for ALU operations in the verifier (Yazhou Tang) and add a test (Eduard Zingerman) - Skip scalar adjustment for BPF_NEG operation if destination register is a pointer (Brahmajit Das) and add a test (KaFai Wan) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: libbpf: Fix missing #pragma in libbpf_utils.c selftests/bpf: Add tests for rejection of ALU ops with negative offsets selftests/bpf: Add test for libbpf_sha256() bpf: Reject negative offsets for ALU ops libbpf: remove linux/unaligned.h dependency for libbpf_sha256() libbpf: move libbpf_sha256() implementation into libbpf_utils.c libbpf: move libbpf_errstr() into libbpf_utils.c libbpf: remove unused libbpf_strerror_r and STRERR_BUFSIZE libbpf: make libbpf_errno.c into more generic libbpf_utils.c selftests/bpf: Add test for BPF_NEG alu on CONST_PTR_TO_MAP bpf: Skip scalar adjustment for BPF_NEG if dst is a pointer selftests/bpf: Fix realloc size in bpf_get_addrs selftests/bpf: Fix typo in subtest_basic_usdt after merge conflict selftests/bpf: Fix open-coded gettid syscall in uprobe syscall tests

Merge tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

2025-10-02T22:58:05Z

Pull slab updates from Vlastimil Babka: - A new layer for caching objects for allocation and free via percpu arrays called sheaves. The aim is to combine the good parts of SLAB (lower-overhead and simpler percpu caching, compared to SLUB) without the past issues with arrays for freeing remote NUMA node objects and their flushing. It also allows more efficient kfree_rcu(), and cheaper object preallocations for cases where the exact number of objects is unknown, but an upper bound is. Currently VMAs and maple nodes are using this new caching, with a plan to enable it for all caches and remove the complex SLUB fastpath based on cpu (partial) slabs and this_cpu_cmpxchg_double(). (Vlastimil Babka, with Liam Howlett and Pedro Falcato for the maple tree changes) - Re-entrant kmalloc_nolock(), which allows opportunistic allocations from NMI and tracing/kprobe contexts. Building on prior page allocator and memcg changes, it will result in removing BPF-specific caches on top of slab (Alexei Starovoitov) - Various fixes and cleanups. (Kuan-Wei Chiu, Matthew Wilcox, Suren Baghdasaryan, Ye Liu) * tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (40 commits) slab: Introduce kmalloc_nolock() and kfree_nolock(). slab: Reuse first bit for OBJEXTS_ALLOC_FAIL slab: Make slub local_(try)lock more precise for LOCKDEP mm: Introduce alloc_frozen_pages_nolock() mm: Allow GFP_ACCOUNT to be used in alloc_pages_nolock(). locking/local_lock: Introduce local_lock_is_locked(). maple_tree: Convert forking to use the sheaf interface maple_tree: Add single node allocation support to maple state maple_tree: Prefilled sheaf conversion and testing tools/testing: Add support for prefilled slab sheafs maple_tree: Replace mt_free_one() with kfree() maple_tree: Use kfree_rcu in ma_free_rcu testing/radix-tree/maple: Hack around kfree_rcu not existing tools/testing: include maple-shim.c in maple.c maple_tree: use percpu sheaves for maple_node_cache mm, vma: use percpu sheaves for vm_area_struct cache tools/testing: Add support for changes to slab for sheaves slab: allow NUMA restricted allocations to use percpu sheaves tools/testing/vma: Implement vm_refcnt reset slab: skip percpu sheaves for remote object freeing ...

bpf: Reject negative offsets for ALU ops

2025-10-01T22:43:13Z

When verifying BPF programs, the check_alu_op() function validates instructions with ALU operations. The 'offset' field in these instructions is a signed 16-bit integer. The existing check 'insn->off > 1' was intended to ensure the offset is either 0, or 1 for BPF_MOD/BPF_DIV. However, because 'insn->off' is signed, this check incorrectly accepts all negative values (e.g., -1). This commit tightens the validation by changing the condition to '(insn->off != 0 && insn->off != 1)'. This ensures that any value other than the explicitly permitted 0 and 1 is rejected, hardening the verifier against malformed BPF programs. Co-developed-by: Shenghao Yuan Signed-off-by: Shenghao Yuan Co-developed-by: Tianci Cao Signed-off-by: Tianci Cao Signed-off-by: Yazhou Tang Acked-by: Yonghong Song Fixes: ec0e2da95f72 ("bpf: Support new signed div/mod instructions.") Link: https://lore.kernel.org/r/tencent_70D024BAE70A0A309A4781694C7B764B0608@qq.com Signed-off-by: Alexei Starovoitov

bpf: Skip scalar adjustment for BPF_NEG if dst is a pointer

2025-10-01T20:53:20Z

In check_alu_op(), the verifier currently calls check_reg_arg() and adjust_scalar_min_max_vals() unconditionally for BPF_NEG operations. However, if the destination register holds a pointer, these scalar adjustments are unnecessary and potentially incorrect. This patch adds a check to skip the adjustment logic when the destination register contains a pointer. Reported-by: syzbot+d36d5ae81e1b0a53ef58@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d36d5ae81e1b0a53ef58 Fixes: aced132599b3 ("bpf: Add range tracking for BPF_NEG") Suggested-by: KaFai Wan Suggested-by: Eduard Zingerman Signed-off-by: Brahmajit Das Acked-by: Eduard Zingerman Link: https://lore.kernel.org/r/20251001191739.2323644-2-listout@listout.xyz Signed-off-by: Alexei Starovoitov

Merge tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2025-10-01T00:58:11Z

Pull bpf updates from Alexei Starovoitov: - Support pulling non-linear xdp data with bpf_xdp_pull_data() kfunc (Amery Hung) Applied as a stable branch in bpf-next and net-next trees. - Support reading skb metadata via bpf_dynptr (Jakub Sitnicki) Also a stable branch in bpf-next and net-next trees. - Enforce expected_attach_type for tailcall compatibility (Daniel Borkmann) - Replace path-sensitive with path-insensitive live stack analysis in the verifier (Eduard Zingerman) This is a significant change in the verification logic. More details, motivation, long term plans are in the cover letter/merge commit. - Support signed BPF programs (KP Singh) This is another major feature that took years to materialize. Algorithm details are in the cover letter/marge commit - Add support for may_goto instruction to s390 JIT (Ilya Leoshkevich) - Add support for may_goto instruction to arm64 JIT (Puranjay Mohan) - Fix USDT SIB argument handling in libbpf (Jiawei Zhao) - Allow uprobe-bpf program to change context registers (Jiri Olsa) - Support signed loads from BPF arena (Kumar Kartikeya Dwivedi and Puranjay Mohan) - Allow access to union arguments in tracing programs (Leon Hwang) - Optimize rcu_read_lock() + migrate_disable() combination where it's used in BPF subsystem (Menglong Dong) - Introduce bpf_task_work_schedule*() kfuncs to schedule deferred execution of BPF callback in the context of a specific task using the kernel’s task_work infrastructure (Mykyta Yatsenko) - Enforce RCU protection for KF_RCU_PROTECTED kfuncs (Kumar Kartikeya Dwivedi) - Add stress test for rqspinlock in NMI (Kumar Kartikeya Dwivedi) - Improve the precision of tnum multiplier verifier operation (Nandakumar Edamana) - Use tnums to improve is_branch_taken() logic (Paul Chaignon) - Add support for atomic operations in arena in riscv JIT (Pu Lehui) - Report arena faults to BPF error stream (Puranjay Mohan) - Search for tracefs at /sys/kernel/tracing first in bpftool (Quentin Monnet) - Add bpf_strcasecmp() kfunc (Rong Tao) - Support lookup_and_delete_elem command in BPF_MAP_STACK_TRACE (Tao Chen) * tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (197 commits) libbpf: Replace AF_ALG with open coded SHA-256 selftests/bpf: Add stress test for rqspinlock in NMI selftests/bpf: Add test case for different expected_attach_type bpf: Enforce expected_attach_type for tailcall compatibility bpftool: Remove duplicate string.h header bpf: Remove duplicate crypto/sha2.h header libbpf: Fix error when st-prefix_ops and ops from differ btf selftests/bpf: Test changing packet data from kfunc selftests/bpf: Add stacktrace map lookup_and_delete_elem test case selftests/bpf: Refactor stacktrace_map case with skeleton bpf: Add lookup_and_delete_elem for BPF_MAP_STACK_TRACE selftests/bpf: Fix flaky bpf_cookie selftest selftests/bpf: Test changing packet data from global functions with a kfunc bpf: Emit struct bpf_xdp_sock type in vmlinux BTF selftests/bpf: Task_work selftest cleanup fixes MAINTAINERS: Delete inactive maintainers from AF_XDP bpf: Mark kfuncs as __noclone selftests/bpf: Add kprobe multi write ctx attach test selftests/bpf: Add kprobe write ctx attach test selftests/bpf: Add uprobe context ip register change test ...