提交 5e751e99 编写于 作者: D David Howells 提交者: James Morris

CRED: Rename cred_exec_mutex to reflect that it's a guard against ptrace

Rename cred_exec_mutex to reflect that it's a guard against foreign
intervention on a process's credential state, such as is made by ptrace().  The
attachment of a debugger to a process affects execve()'s calculation of the new
credential state - _and_ also setprocattr()'s calculation of that state.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>
上级 d2541170
...@@ -1488,7 +1488,7 @@ int compat_do_execve(char * filename, ...@@ -1488,7 +1488,7 @@ int compat_do_execve(char * filename,
if (!bprm) if (!bprm)
goto out_files; goto out_files;
retval = mutex_lock_interruptible(&current->cred_exec_mutex); retval = mutex_lock_interruptible(&current->cred_guard_mutex);
if (retval < 0) if (retval < 0)
goto out_free; goto out_free;
current->in_execve = 1; current->in_execve = 1;
...@@ -1550,7 +1550,7 @@ int compat_do_execve(char * filename, ...@@ -1550,7 +1550,7 @@ int compat_do_execve(char * filename,
/* execve succeeded */ /* execve succeeded */
current->fs->in_exec = 0; current->fs->in_exec = 0;
current->in_execve = 0; current->in_execve = 0;
mutex_unlock(&current->cred_exec_mutex); mutex_unlock(&current->cred_guard_mutex);
acct_update_integrals(current); acct_update_integrals(current);
free_bprm(bprm); free_bprm(bprm);
if (displaced) if (displaced)
...@@ -1573,7 +1573,7 @@ int compat_do_execve(char * filename, ...@@ -1573,7 +1573,7 @@ int compat_do_execve(char * filename,
out_unlock: out_unlock:
current->in_execve = 0; current->in_execve = 0;
mutex_unlock(&current->cred_exec_mutex); mutex_unlock(&current->cred_guard_mutex);
out_free: out_free:
free_bprm(bprm); free_bprm(bprm);
......
...@@ -1045,7 +1045,7 @@ void install_exec_creds(struct linux_binprm *bprm) ...@@ -1045,7 +1045,7 @@ void install_exec_creds(struct linux_binprm *bprm)
commit_creds(bprm->cred); commit_creds(bprm->cred);
bprm->cred = NULL; bprm->cred = NULL;
/* cred_exec_mutex must be held at least to this point to prevent /* cred_guard_mutex must be held at least to this point to prevent
* ptrace_attach() from altering our determination of the task's * ptrace_attach() from altering our determination of the task's
* credentials; any time after this it may be unlocked */ * credentials; any time after this it may be unlocked */
...@@ -1055,7 +1055,7 @@ EXPORT_SYMBOL(install_exec_creds); ...@@ -1055,7 +1055,7 @@ EXPORT_SYMBOL(install_exec_creds);
/* /*
* determine how safe it is to execute the proposed program * determine how safe it is to execute the proposed program
* - the caller must hold current->cred_exec_mutex to protect against * - the caller must hold current->cred_guard_mutex to protect against
* PTRACE_ATTACH * PTRACE_ATTACH
*/ */
int check_unsafe_exec(struct linux_binprm *bprm) int check_unsafe_exec(struct linux_binprm *bprm)
...@@ -1297,7 +1297,7 @@ int do_execve(char * filename, ...@@ -1297,7 +1297,7 @@ int do_execve(char * filename,
if (!bprm) if (!bprm)
goto out_files; goto out_files;
retval = mutex_lock_interruptible(&current->cred_exec_mutex); retval = mutex_lock_interruptible(&current->cred_guard_mutex);
if (retval < 0) if (retval < 0)
goto out_free; goto out_free;
current->in_execve = 1; current->in_execve = 1;
...@@ -1360,7 +1360,7 @@ int do_execve(char * filename, ...@@ -1360,7 +1360,7 @@ int do_execve(char * filename,
/* execve succeeded */ /* execve succeeded */
current->fs->in_exec = 0; current->fs->in_exec = 0;
current->in_execve = 0; current->in_execve = 0;
mutex_unlock(&current->cred_exec_mutex); mutex_unlock(&current->cred_guard_mutex);
acct_update_integrals(current); acct_update_integrals(current);
free_bprm(bprm); free_bprm(bprm);
if (displaced) if (displaced)
...@@ -1383,7 +1383,7 @@ int do_execve(char * filename, ...@@ -1383,7 +1383,7 @@ int do_execve(char * filename,
out_unlock: out_unlock:
current->in_execve = 0; current->in_execve = 0;
mutex_unlock(&current->cred_exec_mutex); mutex_unlock(&current->cred_guard_mutex);
out_free: out_free:
free_bprm(bprm); free_bprm(bprm);
......
...@@ -145,8 +145,8 @@ extern struct cred init_cred; ...@@ -145,8 +145,8 @@ extern struct cred init_cred;
.group_leader = &tsk, \ .group_leader = &tsk, \
.real_cred = &init_cred, \ .real_cred = &init_cred, \
.cred = &init_cred, \ .cred = &init_cred, \
.cred_exec_mutex = \ .cred_guard_mutex = \
__MUTEX_INITIALIZER(tsk.cred_exec_mutex), \ __MUTEX_INITIALIZER(tsk.cred_guard_mutex), \
.comm = "swapper", \ .comm = "swapper", \
.thread = INIT_THREAD, \ .thread = INIT_THREAD, \
.fs = &init_fs, \ .fs = &init_fs, \
......
...@@ -1247,7 +1247,9 @@ struct task_struct { ...@@ -1247,7 +1247,9 @@ struct task_struct {
* credentials (COW) */ * credentials (COW) */
const struct cred *cred; /* effective (overridable) subjective task const struct cred *cred; /* effective (overridable) subjective task
* credentials (COW) */ * credentials (COW) */
struct mutex cred_exec_mutex; /* execve vs ptrace cred calculation mutex */ struct mutex cred_guard_mutex; /* guard against foreign influences on
* credential calculations
* (notably. ptrace) */
char comm[TASK_COMM_LEN]; /* executable name excluding path char comm[TASK_COMM_LEN]; /* executable name excluding path
- access with [gs]et_task_comm (which lock - access with [gs]et_task_comm (which lock
......
...@@ -167,7 +167,7 @@ EXPORT_SYMBOL(prepare_creds); ...@@ -167,7 +167,7 @@ EXPORT_SYMBOL(prepare_creds);
/* /*
* Prepare credentials for current to perform an execve() * Prepare credentials for current to perform an execve()
* - The caller must hold current->cred_exec_mutex * - The caller must hold current->cred_guard_mutex
*/ */
struct cred *prepare_exec_creds(void) struct cred *prepare_exec_creds(void)
{ {
...@@ -276,7 +276,7 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) ...@@ -276,7 +276,7 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags)
struct cred *new; struct cred *new;
int ret; int ret;
mutex_init(&p->cred_exec_mutex); mutex_init(&p->cred_guard_mutex);
if ( if (
#ifdef CONFIG_KEYS #ifdef CONFIG_KEYS
......
...@@ -185,10 +185,11 @@ int ptrace_attach(struct task_struct *task) ...@@ -185,10 +185,11 @@ int ptrace_attach(struct task_struct *task)
if (same_thread_group(task, current)) if (same_thread_group(task, current))
goto out; goto out;
/* Protect exec's credential calculations against our interference; /* Protect the target's credential calculations against our
* SUID, SGID and LSM creds get determined differently under ptrace. * interference; SUID, SGID and LSM creds get determined differently
* under ptrace.
*/ */
retval = mutex_lock_interruptible(&task->cred_exec_mutex); retval = mutex_lock_interruptible(&task->cred_guard_mutex);
if (retval < 0) if (retval < 0)
goto out; goto out;
...@@ -232,7 +233,7 @@ int ptrace_attach(struct task_struct *task) ...@@ -232,7 +233,7 @@ int ptrace_attach(struct task_struct *task)
bad: bad:
write_unlock_irqrestore(&tasklist_lock, flags); write_unlock_irqrestore(&tasklist_lock, flags);
task_unlock(task); task_unlock(task);
mutex_unlock(&task->cred_exec_mutex); mutex_unlock(&task->cred_guard_mutex);
out: out:
return retval; return retval;
} }
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册