Commit 45d9bb0e authored by Al Viro's avatar Al Viro
Browse files

[PATCH] deal with deadlocks in audit_free() 



Don't assume that audit_log_exit() et.al. are called for the context of
current; pass task explictly.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent e0a515bc

kernel/auditsc.c

+10 −10
Original line number Diff line number Diff line
@@ -536,13 +536,13 @@ static void audit_log_task_context(struct audit_buffer *ab, gfp_t gfp_mask) 
	return;

}



static void audit_log_task_info(struct audit_buffer *ab, gfp_t gfp_mask)

static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk, gfp_t gfp_mask)

{

	char name[sizeof(current->comm)];

	struct mm_struct *mm = current->mm;

	char name[sizeof(tsk->comm)];

	struct mm_struct *mm = tsk->mm;

	struct vm_area_struct *vma;



	get_task_comm(name, current);

	get_task_comm(name, tsk);

	audit_log_format(ab, " comm=");

	audit_log_untrustedstring(ab, name);
@@ -551,7 +551,7 @@ static void audit_log_task_info(struct audit_buffer *ab, gfp_t gfp_mask) 


	/*

	 * this is brittle; all callers that pass GFP_ATOMIC will have

	 * NULL current->mm and we won't get here.

	 * NULL tsk->mm and we won't get here.

	 */

	down_read(&mm->mmap_sem);

	vma = mm->mmap;
@@ -569,7 +569,7 @@ static void audit_log_task_info(struct audit_buffer *ab, gfp_t gfp_mask) 
	audit_log_task_context(ab, gfp_mask);

}



static void audit_log_exit(struct audit_context *context, gfp_t gfp_mask)

static void audit_log_exit(struct audit_context *context, struct task_struct *tsk, gfp_t gfp_mask)

{

	int i;

	struct audit_buffer *ab;
@@ -587,8 +587,8 @@ static void audit_log_exit(struct audit_context *context, gfp_t gfp_mask) 
		audit_log_format(ab, " success=%s exit=%ld", 

				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",

				 context->return_code);

	if (current->signal->tty && current->signal->tty->name)

		tty = current->signal->tty->name;

	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)

		tty = tsk->signal->tty->name;

	else

		tty = "(none)";

	audit_log_format(ab,
@@ -720,7 +720,7 @@ void audit_free(struct task_struct *tsk) 
	 * We use GFP_ATOMIC here because we might be doing this 

	 * in the context of the idle thread */

	if (context->in_syscall && context->auditable)

		audit_log_exit(context, GFP_ATOMIC);

		audit_log_exit(context, tsk, GFP_ATOMIC);



	audit_free_context(context);

}
@@ -839,7 +839,7 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code) 
		goto out;



	if (context->in_syscall && context->auditable)

		audit_log_exit(context, GFP_KERNEL);

		audit_log_exit(context, tsk, GFP_KERNEL);



	context->in_syscall = 0;

	context->auditable  = 0;