diff options
| -rw-r--r-- | fs/fhandle.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/fs/fhandle.c b/fs/fhandle.c index f0b818f08aaa..e17029b1dc44 100644 --- a/fs/fhandle.c +++ b/fs/fhandle.c @@ -279,28 +279,32 @@ static int do_handle_to_path(struct file_handle *handle, struct path *path, return 0; } -/* - * Allow relaxed permissions of file handles if the caller has the - * ability to mount the filesystem or create a bind-mount of the - * provided @mountdirfd. - * - * In both cases the caller may be able to get an unobstructed way to - * the encoded file handle. If the caller is only able to create a - * bind-mount we need to verify that there are no locked mounts on top - * of it that could prevent us from getting to the encoded file. - * - * In principle, locked mounts can prevent the caller from mounting the - * filesystem but that only applies to procfs and sysfs neither of which - * support decoding file handles. - */ static inline bool may_decode_fh(struct handle_to_path_ctx *ctx, unsigned int o_flags) { struct path *root = &ctx->root; + if (capable(CAP_DAC_READ_SEARCH)) + return true; + /* - * Restrict to O_DIRECTORY to provide a deterministic API that avoids a - * confusing api in the face of disconnected non-dir dentries. + * Allow relaxed permissions of file handles if the caller has + * the ability to mount the filesystem or create a bind-mount of + * the provided @mountdirfd. + * + * In both cases the caller may be able to get an unobstructed + * way to the encoded file handle. If the caller is only able to + * create a bind-mount we need to verify that there are no + * locked mounts on top of it that could prevent us from getting + * to the encoded file. + * + * In principle, locked mounts can prevent the caller from + * mounting the filesystem but that only applies to procfs and + * sysfs neither of which support decoding file handles. + * + * Restrict to O_DIRECTORY to provide a deterministic API that + * avoids a confusing api in the face of disconnected non-dir + * dentries. * * There's only one dentry for each directory inode (VFS rule)... */ @@ -337,7 +341,7 @@ static int handle_to_path(int mountdirfd, struct file_handle __user *ufh, if (retval) goto out_err; - if (!capable(CAP_DAC_READ_SEARCH) && !may_decode_fh(&ctx, o_flags)) { + if (!may_decode_fh(&ctx, o_flags)) { retval = -EPERM; goto out_path; } |