The patch titled
umh: creds: kill subprocess_info->cred logic
has been added to the -mm tree. Its filename is
umh-creds-kill-subprocess_info-cred-logic.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: umh: creds: kill subprocess_info->cred logic
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Now that nobody ever changes subprocess_info->cred we can kill this member
and related code. ____call_usermodehelper() always runs in the context of
freshly forked kernel thread, it has the proper ->cred copied from its
parent kthread, keventd.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Acked-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/cred.h | 1
include/linux/kmod.h | 1
kernel/cred.c | 54 -----------------------------------------
kernel/kmod.c | 19 --------------
4 files changed, 75 deletions(-)
diff -puN include/linux/cred.h~umh-creds-kill-subprocess_info-cred-logic include/linux/cred.h
--- a/include/linux/cred.h~umh-creds-kill-subprocess_info-cred-logic
+++ a/include/linux/cred.h
@@ -156,7 +156,6 @@ extern int copy_creds(struct task_struct
extern struct cred *cred_alloc_blank(void);
extern struct cred *prepare_creds(void);
extern struct cred *prepare_exec_creds(void);
-extern struct cred *prepare_usermodehelper_creds(void);
extern int commit_creds(struct cred *);
extern void abort_creds(struct cred *);
extern const struct cred *override_creds(const struct cred *);
diff -puN include/linux/kmod.h~umh-creds-kill-subprocess_info-cred-logic include/linux/kmod.h
--- a/include/linux/kmod.h~umh-creds-kill-subprocess_info-cred-logic
+++ a/include/linux/kmod.h
@@ -56,7 +56,6 @@ enum umh_wait {
struct subprocess_info {
struct work_struct work;
struct completion *complete;
- struct cred *cred;
char *path;
char **argv;
char **envp;
diff -puN kernel/cred.c~umh-creds-kill-subprocess_info-cred-logic kernel/cred.c
--- a/kernel/cred.c~umh-creds-kill-subprocess_info-cred-logic
+++ a/kernel/cred.c
@@ -347,60 +347,6 @@ struct cred *prepare_exec_creds(void)
}
/*
- * prepare new credentials for the usermode helper dispatcher
- */
-struct cred *prepare_usermodehelper_creds(void)
-{
-#ifdef CONFIG_KEYS
- struct thread_group_cred *tgcred = NULL;
-#endif
- struct cred *new;
-
-#ifdef CONFIG_KEYS
- tgcred = kzalloc(sizeof(*new->tgcred), GFP_ATOMIC);
- if (!tgcred)
- return NULL;
-#endif
-
- new = kmem_cache_alloc(cred_jar, GFP_ATOMIC);
- if (!new)
- return NULL;
-
- kdebug("prepare_usermodehelper_creds() alloc %p", new);
-
- memcpy(new, &init_cred, sizeof(struct cred));
-
- atomic_set(&new->usage, 1);
- set_cred_subscribers(new, 0);
- get_group_info(new->group_info);
- get_uid(new->user);
-
-#ifdef CONFIG_KEYS
- new->thread_keyring = NULL;
- new->request_key_auth = NULL;
- new->jit_keyring = KEY_REQKEY_DEFL_DEFAULT;
-
- atomic_set(&tgcred->usage, 1);
- spin_lock_init(&tgcred->lock);
- new->tgcred = tgcred;
-#endif
-
-#ifdef CONFIG_SECURITY
- new->security = NULL;
-#endif
- if (security_prepare_creds(new, &init_cred, GFP_ATOMIC) < 0)
- goto error;
- validate_creds(new);
-
- BUG_ON(atomic_read(&new->usage) != 1);
- return new;
-
-error:
- put_cred(new);
- return NULL;
-}
-
-/*
* Copy credentials for the new process created by fork()
*
* We share if we can, but under some circumstances we have to generate a new
diff -puN kernel/kmod.c~umh-creds-kill-subprocess_info-cred-logic kernel/kmod.c
--- a/kernel/kmod.c~umh-creds-kill-subprocess_info-cred-logic
+++ a/kernel/kmod.c
@@ -134,8 +134,6 @@ static int ____call_usermodehelper(void
struct subprocess_info *sub_info = data;
int retval;
- BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
-
/* Unblock all signals */
spin_lock_irq(¤t->sighand->siglock);
flush_signal_handlers(current, 1);
@@ -143,10 +141,6 @@ static int ____call_usermodehelper(void
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
- /* Install the credentials */
- commit_creds(sub_info->cred);
- sub_info->cred = NULL;
-
/* We can run anywhere, unlike our parent keventd(). */
set_cpus_allowed_ptr(current, cpu_all_mask);
@@ -174,8 +168,6 @@ void call_usermodehelper_freeinfo(struct
{
if (info->cleanup)
(*info->cleanup)(info);
- if (info->cred)
- put_cred(info->cred);
kfree(info);
}
EXPORT_SYMBOL(call_usermodehelper_freeinfo);
@@ -231,8 +223,6 @@ static void __call_usermodehelper(struct
pid_t pid;
enum umh_wait wait = sub_info->wait;
- BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
-
/* CLONE_VFORK: wait until the usermode helper has execve'd
* successfully We need the data structures to stay around
* until that is done. */
@@ -355,12 +345,6 @@ struct subprocess_info *call_usermodehel
sub_info->path = path;
sub_info->argv = argv;
sub_info->envp = envp;
- sub_info->cred = prepare_usermodehelper_creds();
- if (!sub_info->cred) {
- kfree(sub_info);
- return NULL;
- }
-
out:
return sub_info;
}
@@ -411,9 +395,6 @@ int call_usermodehelper_exec(struct subp
DECLARE_COMPLETION_ONSTACK(done);
int retval = 0;
- BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
- validate_creds(sub_info->cred);
-
helper_lock();
if (sub_info->path[0] == '\0')
goto out;
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
linux-next.patch
posix-cpu-timers-reset-expire-cache-when-no-timer-is-running.patch
cpu-timers-simplify-rlimit_cpu-handling.patch
cpu-timers-cleanup-arm_timer.patch
cpu-timers-return-correct-previous-timer-reload-value.patch
cpu-timers-change-sigev_none-timer-implementation.patch
cpu-timers-assure-to-not-iterate-over-all-threads-in-fastpath_timer_check.patch
cpu-timers-optimize-run_posix_cpu_timers.patch
proc-cleanup-remove-unused-assignments.patch
kmod-add-init-function-to-usermodehelper.patch
exec-replace-call_usermodehelper_pipe-with-use-of-umh-init-function-and-resolve-limit.patch
umh-creds-convert-call_usermodehelper_keys-to-use-subprocess_info-init.patch
umh-creds-kill-subprocess_info-cred-logic.patch
call_usermodehelper-no-need-to-unblock-signals.patch
wait_for_helper-sigchld-from-user-space-can-lead-to-use-after-free.patch
call_usermodehelper-simplify-fix-umh_no_wait-case.patch
call_usermodehelper-umh_wait_exec-ignores-kernel_thread-failure.patch
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