diff options
| author | Song Liu <song@kernel.org> | 2025-06-13 08:28:56 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-06-17 18:40:59 +0300 |
| commit | a766cfbbeb3a74397965a8fa2e9a402026d3e1d8 (patch) | |
| tree | 24adc39841dec7916f7ae7ead60c890731e02c35 /tools/testing/selftests/bpf/progs | |
| parent | 9afe652958c3ee88f24df1e4a97f298afce89407 (diff) | |
| download | linux-a766cfbbeb3a74397965a8fa2e9a402026d3e1d8.tar.xz | |
bpf: Mark dentry->d_inode as trusted_or_null
LSM hooks such as security_path_mknod() and security_inode_rename() have
access to newly allocated negative dentry, which has NULL d_inode.
Therefore, it is necessary to do the NULL pointer check for d_inode.
Also add selftests that checks the verifier enforces the NULL pointer
check.
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/r/20250613052857.1992233-1-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_vfs_accept.c | 18 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/verifier_vfs_reject.c | 15 |
2 files changed, 33 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c b/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c index a7c0a553aa50..3e2d76ee8050 100644 --- a/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c +++ b/tools/testing/selftests/bpf/progs/verifier_vfs_accept.c @@ -2,6 +2,7 @@ /* Copyright (c) 2024 Google LLC. */ #include <vmlinux.h> +#include <errno.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> @@ -82,4 +83,21 @@ int BPF_PROG(path_d_path_from_file_argument, struct file *file) return 0; } +SEC("lsm.s/inode_rename") +__success +int BPF_PROG(inode_rename, struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + struct inode *inode = new_dentry->d_inode; + ino_t ino; + + if (!inode) + return 0; + ino = inode->i_ino; + if (ino == 0) + return -EACCES; + return 0; +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c b/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c index d6d3f4fcb24c..4b392c6c8fc4 100644 --- a/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c +++ b/tools/testing/selftests/bpf/progs/verifier_vfs_reject.c @@ -2,6 +2,7 @@ /* Copyright (c) 2024 Google LLC. */ #include <vmlinux.h> +#include <errno.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> #include <linux/limits.h> @@ -158,4 +159,18 @@ int BPF_PROG(path_d_path_kfunc_non_lsm, struct path *path, struct file *f) return 0; } +SEC("lsm.s/inode_rename") +__failure __msg("invalid mem access 'trusted_ptr_or_null_'") +int BPF_PROG(inode_rename, struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + struct inode *inode = new_dentry->d_inode; + ino_t ino; + + ino = inode->i_ino; + if (ino == 0) + return -EACCES; + return 0; +} char _license[] SEC("license") = "GPL"; |