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authorChristian Brauner <brauner@kernel.org>2022-09-22 17:17:22 +0200
committerChristian Brauner (Microsoft) <brauner@kernel.org>2022-10-20 10:13:31 +0200
commit318e66856ddec05384f32d60b5598128289f4e7b (patch)
tree5df1c4b7fbc3e2328be5f016393f2c6decf99b20 /fs/xattr.c
parent31acceb97500dd6e9105526301d76488cd6ca21c (diff)
xattr: use posix acl api
In previous patches we built a new posix api solely around get and set inode operations. Now that we have all the pieces in place we can switch the system calls and the vfs over to only rely on this api when interacting with posix acls. This finally removes all type unsafety and type conversion issues explained in detail in [1] that we aim to get rid of. With the new posix acl api we immediately translate into an appropriate kernel internal struct posix_acl format both when getting and setting posix acls. This is a stark contrast to before were we hacked unsafe raw values into the uapi struct that was stored in a void pointer relying and having filesystems and security modules hack around in the uapi struct as well. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Diffstat (limited to 'fs/xattr.c')
-rw-r--r--fs/xattr.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/fs/xattr.c b/fs/xattr.c
index 9ed9eea4d1b9..77db5aa26d13 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -189,6 +189,9 @@ __vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
{
const struct xattr_handler *handler;
+ if (is_posix_acl_xattr(name))
+ return -EOPNOTSUPP;
+
handler = xattr_resolve_name(inode, &name);
if (IS_ERR(handler))
return PTR_ERR(handler);
@@ -410,6 +413,9 @@ __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
{
const struct xattr_handler *handler;
+ if (is_posix_acl_xattr(name))
+ return -EOPNOTSUPP;
+
handler = xattr_resolve_name(inode, &name);
if (IS_ERR(handler))
return PTR_ERR(handler);
@@ -482,6 +488,9 @@ __vfs_removexattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct inode *inode = d_inode(dentry);
const struct xattr_handler *handler;
+ if (is_posix_acl_xattr(name))
+ return -EOPNOTSUPP;
+
handler = xattr_resolve_name(inode, &name);
if (IS_ERR(handler))
return PTR_ERR(handler);
@@ -591,17 +600,13 @@ int setxattr_copy(const char __user *name, struct xattr_ctx *ctx)
return error;
}
-static void setxattr_convert(struct user_namespace *mnt_userns,
- struct dentry *d, struct xattr_ctx *ctx)
-{
- if (ctx->size && is_posix_acl_xattr(ctx->kname->name))
- posix_acl_fix_xattr_from_user(ctx->kvalue, ctx->size);
-}
-
int do_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct xattr_ctx *ctx)
{
- setxattr_convert(mnt_userns, dentry, ctx);
+ if (is_posix_acl_xattr(ctx->kname->name))
+ return do_set_acl(mnt_userns, dentry, ctx->kname->name,
+ ctx->kvalue, ctx->size);
+
return vfs_setxattr(mnt_userns, dentry, ctx->kname->name,
ctx->kvalue, ctx->size, ctx->flags);
}
@@ -708,10 +713,11 @@ do_getxattr(struct user_namespace *mnt_userns, struct dentry *d,
return -ENOMEM;
}
- error = vfs_getxattr(mnt_userns, d, kname, ctx->kvalue, ctx->size);
+ if (is_posix_acl_xattr(ctx->kname->name))
+ error = do_get_acl(mnt_userns, d, kname, ctx->kvalue, ctx->size);
+ else
+ error = vfs_getxattr(mnt_userns, d, kname, ctx->kvalue, ctx->size);
if (error > 0) {
- if (is_posix_acl_xattr(kname))
- posix_acl_fix_xattr_to_user(ctx->kvalue, error);
if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error))
error = -EFAULT;
} else if (error == -ERANGE && ctx->size >= XATTR_SIZE_MAX) {
@@ -886,6 +892,9 @@ removexattr(struct user_namespace *mnt_userns, struct dentry *d,
if (error < 0)
return error;
+ if (is_posix_acl_xattr(kname))
+ return vfs_remove_acl(mnt_userns, d, kname);
+
return vfs_removexattr(mnt_userns, d, kname);
}