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Diffstat (limited to 'fs/exec.c')
-rw-r--r--fs/exec.c49
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);