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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c67
1 files changed, 46 insertions, 21 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 0a601cae23de..3cb616d38d9c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -183,6 +183,9 @@ static int acl_permission_check(struct inode *inode, int mask, unsigned int flag
mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
+ if (current_user_ns() != inode_userns(inode))
+ goto other_perms;
+
if (current_fsuid() == inode->i_uid)
mode >>= 6;
else {
@@ -196,6 +199,7 @@ static int acl_permission_check(struct inode *inode, int mask, unsigned int flag
mode >>= 3;
}
+other_perms:
/*
* If the DACs are ok we don't need any capability check.
*/
@@ -237,7 +241,7 @@ int generic_permission(struct inode *inode, int mask, unsigned int flags,
* Executable DACs are overridable if at least one exec bit is set.
*/
if (!(mask & MAY_EXEC) || execute_ok(inode))
- if (capable(CAP_DAC_OVERRIDE))
+ if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE))
return 0;
/*
@@ -245,7 +249,7 @@ int generic_permission(struct inode *inode, int mask, unsigned int flags,
*/
mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
- if (capable(CAP_DAC_READ_SEARCH))
+ if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH))
return 0;
return -EACCES;
@@ -654,6 +658,7 @@ static inline int handle_reval_path(struct nameidata *nd)
static inline int exec_permission(struct inode *inode, unsigned int flags)
{
int ret;
+ struct user_namespace *ns = inode_userns(inode);
if (inode->i_op->permission) {
ret = inode->i_op->permission(inode, MAY_EXEC, flags);
@@ -666,7 +671,8 @@ static inline int exec_permission(struct inode *inode, unsigned int flags)
if (ret == -ECHILD)
return ret;
- if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
+ if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
+ ns_capable(ns, CAP_DAC_READ_SEARCH))
goto ok;
return ret;
@@ -753,9 +759,11 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
BUG_ON(nd->flags & LOOKUP_RCU);
+ if (link->mnt == nd->path.mnt)
+ mntget(link->mnt);
+
if (unlikely(current->total_link_count >= 40)) {
*p = ERR_PTR(-ELOOP); /* no ->put_link(), please */
- path_put_conditional(link, nd);
path_put(&nd->path);
return -ELOOP;
}
@@ -765,9 +773,6 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
touch_atime(link->mnt, dentry);
nd_set_link(nd, NULL);
- if (link->mnt == nd->path.mnt)
- mntget(link->mnt);
-
error = security_inode_follow_link(link->dentry, nd);
if (error) {
*p = ERR_PTR(error); /* no ->put_link(), please */
@@ -934,8 +939,7 @@ static int follow_managed(struct path *path, unsigned flags)
if (managed & DCACHE_MANAGE_TRANSIT) {
BUG_ON(!path->dentry->d_op);
BUG_ON(!path->dentry->d_op->d_manage);
- ret = path->dentry->d_op->d_manage(path->dentry,
- false, false);
+ ret = path->dentry->d_op->d_manage(path->dentry, false);
if (ret < 0)
return ret == -EISDIR ? 0 : ret;
}
@@ -988,6 +992,12 @@ int follow_down_one(struct path *path)
return 0;
}
+static inline bool managed_dentry_might_block(struct dentry *dentry)
+{
+ return (dentry->d_flags & DCACHE_MANAGE_TRANSIT &&
+ dentry->d_op->d_manage(dentry, true) < 0);
+}
+
/*
* Skip to top of mountpoint pile in rcuwalk mode. We abort the rcu-walk if we
* meet a managed dentry and we're not walking to "..". True is returned to
@@ -996,19 +1006,26 @@ int follow_down_one(struct path *path)
static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
struct inode **inode, bool reverse_transit)
{
- while (d_mountpoint(path->dentry)) {
+ for (;;) {
struct vfsmount *mounted;
- if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
- !reverse_transit &&
- path->dentry->d_op->d_manage(path->dentry, false, true) < 0)
+ /*
+ * Don't forget we might have a non-mountpoint managed dentry
+ * that wants to block transit.
+ */
+ *inode = path->dentry->d_inode;
+ if (!reverse_transit &&
+ unlikely(managed_dentry_might_block(path->dentry)))
return false;
+
+ if (!d_mountpoint(path->dentry))
+ break;
+
mounted = __lookup_mnt(path->mnt, path->dentry, 1);
if (!mounted)
break;
path->mnt = mounted;
path->dentry = mounted->mnt_root;
nd->seq = read_seqcount_begin(&path->dentry->d_seq);
- *inode = path->dentry->d_inode;
}
if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
@@ -1066,7 +1083,7 @@ failed:
* Care must be taken as namespace_sem may be held (indicated by mounting_here
* being true).
*/
-int follow_down(struct path *path, bool mounting_here)
+int follow_down(struct path *path)
{
unsigned managed;
int ret;
@@ -1087,7 +1104,7 @@ int follow_down(struct path *path, bool mounting_here)
BUG_ON(!path->dentry->d_op);
BUG_ON(!path->dentry->d_op->d_manage);
ret = path->dentry->d_op->d_manage(
- path->dentry, mounting_here, false);
+ path->dentry, false);
if (ret < 0)
return ret == -EISDIR ? 0 : ret;
}
@@ -1646,13 +1663,16 @@ static int path_lookupat(int dfd, const char *name,
err = -ECHILD;
}
- if (!err)
+ if (!err) {
err = handle_reval_path(nd);
+ if (err)
+ path_put(&nd->path);
+ }
if (!err && nd->flags & LOOKUP_DIRECTORY) {
if (!nd->inode->i_op->lookup) {
path_put(&nd->path);
- return -ENOTDIR;
+ err = -ENOTDIR;
}
}
@@ -1844,11 +1864,15 @@ static inline int check_sticky(struct inode *dir, struct inode *inode)
if (!(dir->i_mode & S_ISVTX))
return 0;
+ if (current_user_ns() != inode_userns(inode))
+ goto other_userns;
if (inode->i_uid == fsuid)
return 0;
if (dir->i_uid == fsuid)
return 0;
- return !capable(CAP_FOWNER);
+
+other_userns:
+ return !ns_capable(inode_userns(inode), CAP_FOWNER);
}
/*
@@ -2028,7 +2052,7 @@ static int may_open(struct path *path, int acc_mode, int flag)
}
/* O_NOATIME can only be set by the owner or superuser */
- if (flag & O_NOATIME && !is_owner_or_cap(inode))
+ if (flag & O_NOATIME && !inode_owner_or_capable(inode))
return -EPERM;
/*
@@ -2442,7 +2466,8 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
if (error)
return error;
- if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
+ if ((S_ISCHR(mode) || S_ISBLK(mode)) &&
+ !ns_capable(inode_userns(dir), CAP_MKNOD))
return -EPERM;
if (!dir->i_op->mknod)
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-01 10:31:51 +0300