1 files changed, 32 insertions, 17 deletions

diff --git a/fs/exec.c b/fs/exec.c
index c0c636e34f60..632b02e34ec7 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -826,7 +826,9 @@ static int de_thread(struct task_struct *tsk)
                 attach_pid(tsk, PIDTYPE_PID,  task_pid(leader));
                 transfer_pid(leader, tsk, PIDTYPE_PGID);
                 transfer_pid(leader, tsk, PIDTYPE_SID);
+
                 list_replace_rcu(&leader->tasks, &tsk->tasks);
+                list_replace_init(&leader->sibling, &tsk->sibling);
 
                 tsk->group_leader = tsk;
                 leader->group_leader = tsk;
@@ -923,6 +925,15 @@ char *get_task_comm(char *buf, struct task_struct *tsk)
 void set_task_comm(struct task_struct *tsk, char *buf)
 {
         task_lock(tsk);
+
+        /*
+         * Threads may access current->comm without holding
+         * the task lock, so write the string carefully.
+         * Readers without a lock may see incomplete new
+         * names but are safe from non-terminating string reads.
+         */
+        memset(tsk->comm, 0, TASK_COMM_LEN);
+        wmb();
         strlcpy(tsk->comm, buf, sizeof(tsk->comm));
         task_unlock(tsk);
         perf_event_comm(tsk);
@@ -1752,17 +1763,20 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
         struct mm_struct *mm = current->mm;
         struct linux_binfmt * binfmt;
         struct inode * inode;
-        struct file * file;
         const struct cred *old_cred;
         struct cred *cred;
         int retval = 0;
         int flag = 0;
         int ispipe = 0;
-        unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
         char **helper_argv = NULL;
         int helper_argc = 0;
         int dump_count = 0;
         static atomic_t core_dump_count = ATOMIC_INIT(0);
+        struct coredump_params cprm = {
+                .signr = signr,
+                .regs = regs,
+                .limit = current->signal->rlim[RLIMIT_CORE].rlim_cur,
+        };
 
         audit_core_dumps(signr);
 
@@ -1818,15 +1832,15 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
         ispipe = format_corename(corename, signr);
         unlock_kernel();
 
-        if ((!ispipe) && (core_limit < binfmt->min_coredump))
+        if ((!ispipe) && (cprm.limit < binfmt->min_coredump))
                 goto fail_unlock;
 
         if (ispipe) {
-                if (core_limit == 0) {
+                if (cprm.limit == 0) {
                         /*
                          * Normally core limits are irrelevant to pipes, since
                          * we're not writing to the file system, but we use
-                         * core_limit of 0 here as a speacial value. Any
+                         * cprm.limit of 0 here as a speacial value. Any
                          * non-zero limit gets set to RLIM_INFINITY below, but
                          * a limit of 0 skips the dump.  This is a consistent
                          * way to catch recursive crashes.  We can still crash
@@ -1859,25 +1873,25 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
                         goto fail_dropcount;
                 }
 
-                core_limit = RLIM_INFINITY;
+                cprm.limit = RLIM_INFINITY;
 
                 /* SIGPIPE can happen, but it's just never processed */
                 if (call_usermodehelper_pipe(helper_argv[0], helper_argv, NULL,
-                                &file)) {
+                                &cprm.file)) {
                         printk(KERN_INFO "Core dump to %s pipe failed\n",
                                corename);
                         goto fail_dropcount;
                 }
         } else
-                file = filp_open(corename,
+                cprm.file = filp_open(corename,
                                  O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
                                  0600);
-        if (IS_ERR(file))
+        if (IS_ERR(cprm.file))
                 goto fail_dropcount;
-        inode = file->f_path.dentry->d_inode;
+        inode = cprm.file->f_path.dentry->d_inode;
         if (inode->i_nlink > 1)
                 goto close_fail;        /* multiple links - don't dump */
-        if (!ispipe && d_unhashed(file->f_path.dentry))
+        if (!ispipe && d_unhashed(cprm.file->f_path.dentry))
                 goto close_fail;
 
         /* AK: actually i see no reason to not allow this for named pipes etc.,
@@ -1890,21 +1904,22 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
          */
         if (inode->i_uid != current_fsuid())
                 goto close_fail;
-        if (!file->f_op)
+        if (!cprm.file->f_op)
                 goto close_fail;
-        if (!file->f_op->write)
+        if (!cprm.file->f_op->write)
                 goto close_fail;
-        if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
+        if (!ispipe &&
+            do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file) != 0)
                 goto close_fail;
 
-        retval = binfmt->core_dump(signr, regs, file, core_limit);
+        retval = binfmt->core_dump(&cprm);
 
         if (retval)
                 current->signal->group_exit_code |= 0x80;
 close_fail:
         if (ispipe && core_pipe_limit)
-                wait_for_dump_helpers(file);
-        filp_close(file, NULL);
+                wait_for_dump_helpers(cprm.file);
+        filp_close(cprm.file, NULL);
 fail_dropcount:
         if (dump_count)
                 atomic_dec(&core_dump_count);