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-rw-r--r--fs/proc/base.c102
-rw-r--r--fs/proc/fd.c12
-rw-r--r--fs/proc/internal.h16
3 files changed, 61 insertions, 69 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8e7e61b28f31..ad98d883847a 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1667,12 +1667,63 @@ const struct inode_operations proc_pid_link_inode_operations = {
/* building an inode */
+void task_dump_owner(struct task_struct *task, mode_t mode,
+ kuid_t *ruid, kgid_t *rgid)
+{
+ /* Depending on the state of dumpable compute who should own a
+ * proc file for a task.
+ */
+ const struct cred *cred;
+ kuid_t uid;
+ kgid_t gid;
+
+ /* Default to the tasks effective ownership */
+ rcu_read_lock();
+ cred = __task_cred(task);
+ uid = cred->euid;
+ gid = cred->egid;
+ rcu_read_unlock();
+
+ /*
+ * Before the /proc/pid/status file was created the only way to read
+ * the effective uid of a /process was to stat /proc/pid. Reading
+ * /proc/pid/status is slow enough that procps and other packages
+ * kept stating /proc/pid. To keep the rules in /proc simple I have
+ * made this apply to all per process world readable and executable
+ * directories.
+ */
+ if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
+ struct mm_struct *mm;
+ task_lock(task);
+ mm = task->mm;
+ /* Make non-dumpable tasks owned by some root */
+ if (mm) {
+ if (get_dumpable(mm) != SUID_DUMP_USER) {
+ struct user_namespace *user_ns = mm->user_ns;
+
+ uid = make_kuid(user_ns, 0);
+ if (!uid_valid(uid))
+ uid = GLOBAL_ROOT_UID;
+
+ gid = make_kgid(user_ns, 0);
+ if (!gid_valid(gid))
+ gid = GLOBAL_ROOT_GID;
+ }
+ } else {
+ uid = GLOBAL_ROOT_UID;
+ gid = GLOBAL_ROOT_GID;
+ }
+ task_unlock(task);
+ }
+ *ruid = uid;
+ *rgid = gid;
+}
+
struct inode *proc_pid_make_inode(struct super_block * sb,
struct task_struct *task, umode_t mode)
{
struct inode * inode;
struct proc_inode *ei;
- const struct cred *cred;
/* We need a new inode */
@@ -1694,13 +1745,7 @@ struct inode *proc_pid_make_inode(struct super_block * sb,
if (!ei->pid)
goto out_unlock;
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
security_task_to_inode(task, inode);
out:
@@ -1715,7 +1760,6 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
struct inode *inode = d_inode(dentry);
struct task_struct *task;
- const struct cred *cred;
struct pid_namespace *pid = dentry->d_sb->s_fs_info;
generic_fillattr(inode, stat);
@@ -1733,12 +1777,7 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
*/
return -ENOENT;
}
- if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
- task_dumpable(task)) {
- cred = __task_cred(task);
- stat->uid = cred->euid;
- stat->gid = cred->egid;
- }
+ task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
}
rcu_read_unlock();
return 0;
@@ -1754,18 +1793,11 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
* Rewrite the inode's ownerships here because the owning task may have
* performed a setuid(), etc.
*
- * Before the /proc/pid/status file was created the only way to read
- * the effective uid of a /process was to stat /proc/pid. Reading
- * /proc/pid/status is slow enough that procps and other packages
- * kept stating /proc/pid. To keep the rules in /proc simple I have
- * made this apply to all per process world readable and executable
- * directories.
*/
int pid_revalidate(struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct task_struct *task;
- const struct cred *cred;
if (flags & LOOKUP_RCU)
return -ECHILD;
@@ -1774,17 +1806,8 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
task = get_proc_task(inode);
if (task) {
- if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
- task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
+
inode->i_mode &= ~(S_ISUID | S_ISGID);
security_task_to_inode(task, inode);
put_task_struct(task);
@@ -1881,7 +1904,6 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
bool exact_vma_exists = false;
struct mm_struct *mm = NULL;
struct task_struct *task;
- const struct cred *cred;
struct inode *inode;
int status = 0;
@@ -1906,16 +1928,8 @@ static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
mmput(mm);
if (exact_vma_exists) {
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
+
security_task_to_inode(task, inode);
status = 1;
}
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 4274f83bf100..00ce1531b2f5 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -84,7 +84,6 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
struct files_struct *files;
struct task_struct *task;
- const struct cred *cred;
struct inode *inode;
unsigned int fd;
@@ -108,16 +107,7 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
rcu_read_unlock();
put_files_struct(files);
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 2de5194ba378..e2c3c461fa20 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -97,20 +97,8 @@ static inline struct task_struct *get_proc_task(struct inode *inode)
return get_pid_task(proc_pid(inode), PIDTYPE_PID);
}
-static inline int task_dumpable(struct task_struct *task)
-{
- int dumpable = 0;
- struct mm_struct *mm;
-
- task_lock(task);
- mm = task->mm;
- if (mm)
- dumpable = get_dumpable(mm);
- task_unlock(task);
- if (dumpable == SUID_DUMP_USER)
- return 1;
- return 0;
-}
+void task_dump_owner(struct task_struct *task, mode_t mode,
+ kuid_t *ruid, kgid_t *rgid);
static inline unsigned name_to_int(const struct qstr *qstr)
{
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-01 20:59:10 +0300