From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- net/ceph/buffer.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 net/ceph/buffer.c (limited to 'net/ceph/buffer.c') diff --git a/net/ceph/buffer.c b/net/ceph/buffer.c new file mode 100644 index 000000000..98c2ac438 --- /dev/null +++ b/net/ceph/buffer.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +#include +#include + +#include +#include +#include /* for kvmalloc */ + +struct ceph_buffer *ceph_buffer_new(size_t len, gfp_t gfp) +{ + struct ceph_buffer *b; + + b = kmalloc_obj(*b, gfp); + if (!b) + return NULL; + + b->vec.iov_base = kvmalloc(len, gfp); + if (!b->vec.iov_base) { + kfree(b); + return NULL; + } + + kref_init(&b->kref); + b->alloc_len = len; + b->vec.iov_len = len; + dout("buffer_new %p\n", b); + return b; +} +EXPORT_SYMBOL(ceph_buffer_new); + +void ceph_buffer_release(struct kref *kref) +{ + struct ceph_buffer *b = container_of(kref, struct ceph_buffer, kref); + + dout("buffer_release %p\n", b); + kvfree(b->vec.iov_base); + kfree(b); +} +EXPORT_SYMBOL(ceph_buffer_release); + +int ceph_decode_buffer(struct ceph_buffer **b, void **p, void *end) +{ + size_t len; + + ceph_decode_need(p, end, sizeof(u32), bad); + len = ceph_decode_32(p); + dout("decode_buffer len %d\n", (int)len); + ceph_decode_need(p, end, len, bad); + *b = ceph_buffer_new(len, GFP_NOFS); + if (!*b) + return -ENOMEM; + ceph_decode_copy(p, (*b)->vec.iov_base, len); + return 0; +bad: + return -EINVAL; +} -- cgit v1.3.1