linux/kernel/bpf
Dave Marchevsky a40d363243 bpf: Special verifier handling for bpf_rbtree_{remove, first}
Newly-added bpf_rbtree_{remove,first} kfuncs have some special properties
that require handling in the verifier:

  * both bpf_rbtree_remove and bpf_rbtree_first return the type containing
    the bpf_rb_node field, with the offset set to that field's offset,
    instead of a struct bpf_rb_node *
    * mark_reg_graph_node helper added in previous patch generalizes
      this logic, use it

  * bpf_rbtree_remove's node input is a node that's been inserted
    in the tree - a non-owning reference.

  * bpf_rbtree_remove must invalidate non-owning references in order to
    avoid aliasing issue. Use previously-added
    invalidate_non_owning_refs helper to mark this function as a
    non-owning ref invalidation point.

  * Unlike other functions, which convert one of their input arg regs to
    non-owning reference, bpf_rbtree_first takes no arguments and just
    returns a non-owning reference (possibly null)
    * For now verifier logic for this is special-cased instead of
      adding new kfunc flag.

This patch, along with the previous one, complete special verifier
handling for all rbtree API functions added in this series.

With functional verifier handling of rbtree_remove, under current
non-owning reference scheme, a node type with both bpf_{list,rb}_node
fields could cause the verifier to accept programs which remove such
nodes from collections they haven't been added to.

In order to prevent this, this patch adds a check to btf_parse_fields
which rejects structs with both bpf_{list,rb}_node fields. This is a
temporary measure that can be removed after "collection identity"
followup. See comment added in btf_parse_fields. A linked_list BTF test
exercising the new check is added in this patch as well.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-6-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-13 19:40:53 -08:00
..
preload bpf: iterators: Split iterators.lskel.h into little- and big- endian versions 2023-01-28 12:45:15 -08:00
arraymap.c bpf: Do btf_record_free outside map_free callback 2022-11-17 19:11:31 -08:00
bloom_filter.c treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
bpf_cgrp_storage.c bpf: Fix a compilation failure with clang lto build 2022-11-30 17:13:25 -08:00
bpf_inode_storage.c bpf: Fix a compilation failure with clang lto build 2022-11-30 17:13:25 -08:00
bpf_iter.c bpf: Initialize the bpf_run_ctx in bpf_iter_run_prog() 2022-08-18 17:06:13 -07:00
bpf_local_storage.c bpf: use bpf_map_kvcalloc in bpf_local_storage 2023-02-10 18:59:56 -08:00
bpf_lru_list.c
bpf_lru_list.h printk: stop including cache.h from printk.h 2022-05-13 07:20:07 -07:00
bpf_lsm.c bpf: Fix the kernel crash caused by bpf_setsockopt(). 2023-01-26 23:26:40 -08:00
bpf_struct_ops_types.h bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpf_struct_ops.c mm: Introduce set_memory_rox() 2022-12-15 10:37:26 -08:00
bpf_task_storage.c bpf: Fix a compilation failure with clang lto build 2022-11-30 17:13:25 -08:00
btf.c bpf: Special verifier handling for bpf_rbtree_{remove, first} 2023-02-13 19:40:53 -08:00
cgroup_iter.c bpf: Pin the start cgroup in cgroup_iter_seq_init() 2022-11-21 17:40:42 +01:00
cgroup.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-03 17:44:18 -07:00
core.c bpf: allow to disable bpf prog memory accounting 2023-02-10 18:59:57 -08:00
cpumap.c net: skbuff: drop the word head from skb cache 2023-02-10 09:10:28 +00:00
cpumask.c bpf: Add __bpf_kfunc tag to all kfuncs 2023-02-02 00:25:14 +01:00
devmap.c bpf: devmap: check XDP features in __xdp_enqueue routine 2023-02-02 20:48:24 -08:00
disasm.c bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
disasm.h bpf: Relicense disassembler as GPL-2.0-only OR BSD-2-Clause 2021-09-02 14:49:23 +02:00
dispatcher.c bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func 2022-12-14 12:02:14 -08:00
hashtab.c bpf: hash map, avoid deadlock with suitable hash mask 2023-01-12 18:55:42 -08:00
helpers.c bpf: Add bpf_rbtree_{add,remove,first} kfuncs 2023-02-13 19:40:48 -08:00
inode.c bpf: Convert bpf_preload.ko to use light skeleton. 2022-02-10 23:31:51 +01:00
Kconfig rcu: Make the TASKS_RCU Kconfig option be selected 2022-04-20 16:52:58 -07:00
link_iter.c bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
local_storage.c bpf: Consolidate spin_lock, timer management into btf_record 2022-11-03 22:19:40 -07:00
lpm_trie.c bpf: Use bpf_map_area_alloc consistently on bpf map creation 2022-08-10 11:50:43 -07:00
Makefile bpf: Enable cpumasks to be queried and used as kptrs 2023-01-25 07:57:49 -08:00
map_in_map.c bpf: Add comments for map BTF matching requirement for bpf_list_head 2022-11-17 19:22:14 -08:00
map_in_map.h
map_iter.c bpf: Introduce MEM_RDONLY flag 2021-12-18 13:27:41 -08:00
memalloc.c bpf: allow to disable bpf map memory accounting 2023-02-10 18:59:57 -08:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
net_namespace.c net: Add includes masked by netdevice.h including uapi/bpf.h 2021-12-29 20:03:05 -08:00
offload.c bpf: Drop always true do_idr_lock parameter to bpf_map_free_id 2023-02-02 20:26:12 -08:00
percpu_freelist.c bpf: Initialize same number of free nodes for each pcpu_freelist 2022-11-11 12:05:14 -08:00
percpu_freelist.h
prog_iter.c
queue_stack_maps.c bpf: Remove unneeded memset in queue_stack_map creation 2022-08-10 11:48:22 -07:00
reuseport_array.c net: Fix suspicious RCU usage in bpf_sk_reuseport_detach() 2022-08-17 16:42:59 -07:00
ringbuf.c bpf: Rename MEM_ALLOC to MEM_RINGBUF 2022-11-14 21:52:45 -08:00
stackmap.c perf/bpf: Always use perf callchains if exist 2022-09-13 15:03:22 +02:00
syscall.c bpf: Add basic bpf_rb_{root,node} support 2023-02-13 19:31:13 -08:00
sysfs_btf.c
task_iter.c bpf: keep a reference to the mm, in case the task is dead. 2022-12-28 14:11:48 -08:00
tnum.c
trampoline.c bpf: Fix panic due to wrong pageattr of im->image 2022-12-28 13:46:28 -08:00
verifier.c bpf: Special verifier handling for bpf_rbtree_{remove, first} 2023-02-13 19:40:53 -08:00