diff mbox series

[bpf-next,v2,04/13] bpf: Support bpf_dynptr-typed map key in verifier

Message ID 20220924133620.4147153-5-houtao@huaweicloud.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series Add support for qp-trie with dynptr key | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR fail PR summary
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 10 this patch: 10
netdev/cc_maintainers warning 2 maintainers not CCed: song@kernel.org martin.lau@linux.dev
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 10 this patch: 10
netdev/checkpatch warning WARNING: line length of 84 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 87 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-4 success Logs for llvm-toolchain
bpf/vmtest-bpf-next-VM_Test-5 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-1 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-9 fail Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-6 fail Logs for test_maps on s390x with gcc

Commit Message

Hou Tao Sept. 24, 2022, 1:36 p.m. UTC 
From: Hou Tao <houtao1@huawei.com>

For map with dynptr key, only allow a bpf_dynptr on stack to be used as
a map key.

Signed-off-by: Hou Tao <houtao1@huawei.com>
---
 kernel/bpf/verifier.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 6f6d2d511c06..5d2868a798d6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6020,9 +6020,20 @@  static int check_func_arg(struct bpf_verifier_env *env, u32 arg,
 			verbose(env, "invalid map_ptr to access map->key\n");
 			return -EACCES;
 		}
-		err = check_helper_mem_access(env, regno,
-					      meta->map_ptr->key_size, false,
-					      NULL);
+		/* Allow bpf_dynptr to be used as map key */
+		if (map_key_has_dynptr(meta->map_ptr)) {
+			if (base_type(reg->type) != PTR_TO_STACK ||
+			    !is_dynptr_reg_valid_init(env, reg) ||
+			    !is_dynptr_type_expected(env, reg, ARG_PTR_TO_DYNPTR)) {
+				verbose(env, "expect R%d to be dynptr instead of %s\n",
+					regno, reg_type_str(env, reg->type));
+				return -EACCES;
+			}
+		} else {
+			err = check_helper_mem_access(env, regno,
+						      meta->map_ptr->key_size, false,
+						      NULL);
+		}
 		break;
 	case ARG_PTR_TO_MAP_VALUE:
 		if (type_may_be_null(arg_type) && register_is_null(reg))