linux/kernel/bpf
Alexei Starovoitov 6d94e741a8 bpf: Support for pointers beyond pkt_end.
This patch adds the verifier support to recognize inlined branch conditions.
The LLVM knows that the branch evaluates to the same value, but the verifier
couldn't track it. Hence causing valid programs to be rejected.
The potential LLVM workaround: https://reviews.llvm.org/D87428
can have undesired side effects, since LLVM doesn't know that
skb->data/data_end are being compared. LLVM has to introduce extra boolean
variable and use inline_asm trick to force easier for the verifier assembly.

Instead teach the verifier to recognize that
r1 = skb->data;
r1 += 10;
r2 = skb->data_end;
if (r1 > r2) {
  here r1 points beyond packet_end and
  subsequent
  if (r1 > r2) // always evaluates to "true".
}

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20201111031213.25109-2-alexei.starovoitov@gmail.com
2020-11-13 01:42:11 +01:00
..
preload bpf: Move prog->aux->linked_prog and trampoline into bpf_link on attach 2020-09-29 13:09:23 -07:00
Makefile bpf: Implement task local storage 2020-11-06 08:08:37 -08:00
arraymap.c bpf: Allow for map-in-map with dynamic inner array map entries 2020-10-11 10:21:04 -07:00
bpf_inode_storage.c bpf: Allow specifying a BTF ID per argument in function protos 2020-09-21 15:00:40 -07:00
bpf_iter.c bpf: Permit cond_resched for some iterators 2020-10-28 14:54:31 -07:00
bpf_local_storage.c bpf: Use hlist_add_head_rcu when linking to local_storage 2020-09-19 01:12:35 +02:00
bpf_lru_list.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
bpf_lru_list.h bpf: Fix a typo "inacitve" -> "inactive" 2020-04-06 21:54:10 +02:00
bpf_lsm.c bpf: Implement task local storage 2020-11-06 08:08:37 -08:00
bpf_struct_ops.c bpf: Move btf_resolve_size into __btf_resolve_size 2020-08-25 15:37:41 -07:00
bpf_struct_ops_types.h bpf: tcp: Support tcp_congestion_ops in bpf 2020-01-09 08:46:18 -08:00
bpf_task_storage.c bpf: Fix NULL dereference in bpf_task_storage 2020-11-11 18:14:49 -08:00
btf.c bpf: Compile out btf_parse_module() if module BTF is not enabled 2020-11-10 20:15:07 -08:00
cgroup.c Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-10-22 09:59:21 -07:00
core.c networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
cpumap.c bpf, cpumap: Remove rcpu pointer from cpu_map_build_skb signature 2020-09-28 23:30:42 +02:00
devmap.c bpf: {cpu,dev}map: Change various functions return type from int to void 2020-09-01 15:45:58 +02:00
disasm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
disasm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 295 2019-06-05 17:36:38 +02:00
dispatcher.c bpf: Remove bpf_image tree 2020-03-13 12:49:52 -07:00
hashtab.c bpf: Lift hashtab key_size limit 2020-11-05 20:04:46 -08:00
helpers.c bpf: Introducte bpf_this_cpu_ptr() 2020-10-02 15:00:49 -07:00
inode.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-22 16:45:34 -07:00
local_storage.c bpf/local_storage: Fix build without CONFIG_CGROUP 2020-07-25 20:16:36 -07:00
lpm_trie.c bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
map_in_map.c bpf: Relax max_entries check for most of the inner map types 2020-08-28 15:41:30 +02:00
map_in_map.h bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
map_iter.c bpf: Implement link_query callbacks in map element iterators 2020-08-21 14:01:39 -07:00
net_namespace.c bpf: Add support for forced LINK_DETACH command 2020-08-01 20:38:28 -07:00
offload.c bpf, offload: Replace bitwise AND by logical AND in bpf_prog_offload_info_fill 2020-02-17 16:53:49 +01:00
percpu_freelist.c bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
percpu_freelist.h bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMI 2020-10-06 00:04:11 +02:00
prog_iter.c bpf: Refactor bpf_iter_reg to have separate seq_info member 2020-07-25 20:16:32 -07:00
queue_stack_maps.c bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
reuseport_array.c bpf, net: Rework cookie generator as per-cpu one 2020-09-30 11:50:35 -07:00
ringbuf.c bpf: Add map_meta_equal map ops 2020-08-28 15:41:30 +02:00
stackmap.c bpf: Allow specifying a BTF ID per argument in function protos 2020-09-21 15:00:40 -07:00
syscall.c bpf: Implement task local storage 2020-11-06 08:08:37 -08:00
sysfs_btf.c bpf: Load and verify kernel module BTFs 2020-11-10 15:25:53 -08:00
task_iter.c bpf: Permit cond_resched for some iterators 2020-10-28 14:54:31 -07:00
tnum.c bpf: Verifier, do explicit ALU32 bounds tracking 2020-03-30 14:59:53 -07:00
trampoline.c bpf: Move prog->aux->linked_prog and trampoline into bpf_link on attach 2020-09-29 13:09:23 -07:00
verifier.c bpf: Support for pointers beyond pkt_end. 2020-11-13 01:42:11 +01:00