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authorAlexei Starovoitov2023-04-03 21:50:25 -0700
committerAndrii Nakryiko2023-04-04 16:57:16 -0700
commit91571a515d1bcdc280bb46423bb697ea7eb42ff3 (patch)
tree636320a1ffcdd78b5091e70cca1f5f1353472aef /kernel
parent63260df1396578226ac3134cf7f764690002e70e (diff)
bpf: Teach verifier that certain helpers accept NULL pointer.
bpf_[sk|inode|task|cgrp]_storage_[get|delete]() and bpf_get_socket_cookie() helpers perform run-time check that sk|inode|task|cgrp pointer != NULL. Teach verifier about this fact and allow bpf programs to pass PTR_TO_BTF_ID | PTR_MAYBE_NULL into such helpers. It will be used in the subsequent patch that will do bpf_sk_storage_get(.., skb->sk, ...); Even when 'skb' pointer is trusted the 'sk' pointer may be NULL. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-5-alexei.starovoitov@gmail.com
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/bpf_cgrp_storage.c4
-rw-r--r--kernel/bpf/bpf_inode_storage.c4
-rw-r--r--kernel/bpf/bpf_task_storage.c8
3 files changed, 8 insertions, 8 deletions
diff --git a/kernel/bpf/bpf_cgrp_storage.c b/kernel/bpf/bpf_cgrp_storage.c
index d17d5b694668..d44fe8dd9732 100644
--- a/kernel/bpf/bpf_cgrp_storage.c
+++ b/kernel/bpf/bpf_cgrp_storage.c
@@ -224,7 +224,7 @@ const struct bpf_func_proto bpf_cgrp_storage_get_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &bpf_cgroup_btf_id[0],
.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
.arg4_type = ARG_ANYTHING,
@@ -235,6 +235,6 @@ const struct bpf_func_proto bpf_cgrp_storage_delete_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &bpf_cgroup_btf_id[0],
};
diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
index e17ad581b9be..a4d93df78c75 100644
--- a/kernel/bpf/bpf_inode_storage.c
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -229,7 +229,7 @@ const struct bpf_func_proto bpf_inode_storage_get_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &bpf_inode_storage_btf_ids[0],
.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
.arg4_type = ARG_ANYTHING,
@@ -240,6 +240,6 @@ const struct bpf_func_proto bpf_inode_storage_delete_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &bpf_inode_storage_btf_ids[0],
};
diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c
index d1af0c8f9ce4..adf6dfe0ba68 100644
--- a/kernel/bpf/bpf_task_storage.c
+++ b/kernel/bpf/bpf_task_storage.c
@@ -338,7 +338,7 @@ const struct bpf_func_proto bpf_task_storage_get_recur_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
.arg4_type = ARG_ANYTHING,
@@ -349,7 +349,7 @@ const struct bpf_func_proto bpf_task_storage_get_proto = {
.gpl_only = false,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
.arg4_type = ARG_ANYTHING,
@@ -360,7 +360,7 @@ const struct bpf_func_proto bpf_task_storage_delete_recur_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};
@@ -369,6 +369,6 @@ const struct bpf_func_proto bpf_task_storage_delete_proto = {
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
- .arg2_type = ARG_PTR_TO_BTF_ID,
+ .arg2_type = ARG_PTR_TO_BTF_ID_OR_NULL,
.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};