+ usermodehelper-kill-the-sub_info-path-check.patch added to -mm tree

+ usermodehelper-kill-the-sub_info-path-check.patch added to -mm tree

[akpm]

Subject: + usermodehelper-kill-the-sub_info-path-check.patch added to -mm tree
To: oleg@redhat.com,lucas.de.marchi@gmail.com,rusty@rustcorp.com.au
From: akpm@linux-foundation.org
Date: Tue, 28 May 2013 15:11:05 -0700


The patch titled
     Subject: usermodehelper: kill the sub_info->path[0] check
has been added to the -mm tree.  Its filename is
     usermodehelper-kill-the-sub_info-path-check.patch

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------------------------------------------------------
From: Oleg Nesterov <oleg@redhat.com>
Subject: usermodehelper: kill the sub_info->path[0] check

call_usermodehelper_exec() does nothing but returns success if path[0] ==
0.  The only user which needs this strange feature is request_module(), it
can check modprobe_path[0] itself like other users do if they want to
detect the "disabled by admin" case.

Kill it.  Not only it looks strange, it can confuse other callers.  And
this allows us to revert 264b83c0 ("usermodehelper: check
subprocess_info->path != NULL"), do_execve(NULL) is safe.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/kmod.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff -puN kernel/kmod.c~usermodehelper-kill-the-sub_info-path-check kernel/kmod.c
--- a/kernel/kmod.c~usermodehelper-kill-the-sub_info-path-check
+++ a/kernel/kmod.c
@@ -147,6 +147,9 @@ int __request_module(bool wait, const ch
 	 */
 	WARN_ON_ONCE(wait && current_is_async());
 
+	if (!modprobe_path[0])
+		return 0;
+
 	va_start(args, fmt);
 	ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
 	va_end(args);
@@ -569,14 +572,6 @@ int call_usermodehelper_exec(struct subp
 	int retval = 0;
 
 	helper_lock();
-	if (!sub_info->path) {
-		retval = -EINVAL;
-		goto out;
-	}
-
-	if (sub_info->path[0] == '\0')
-		goto out;
-
 	if (!khelper_wq || usermodehelper_disabled) {
 		retval = -EBUSY;
 		goto out;
_

Patches currently in -mm which might be from oleg@redhat.com are

posix_cpu_timer-consolidate-expiry-time-type.patch
posix_cpu_timers-consolidate-timer-list-cleanups.patch
posix_cpu_timers-consolidate-expired-timers-check.patch
posix-timers-correctly-get-dying-task-time-sample-in-posix_cpu_timer_schedule.patch
posix_timers-fix-racy-timer-delta-caching-on-task-exit.patch
lockdep-introduce-lock_acquire_exclusive-shared-helper-macros.patch
lglock-update-lockdep-annotations-to-report-recursive-local-locks.patch
autofs4-allow-autofs-to-work-outside-the-initial-pid-namespace.patch
autofs4-translate-pids-to-the-right-namespace-for-the-daemon.patch
ptrace-x86-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints.patch
ptrace-powerpc-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints.patch
ptrace-arm-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints.patch
ptrace-sh-revert-hw_breakpoints-fix-racy-access-to-ptrace-breakpoints.patch
ptrace-revert-prepare-to-fix-racy-accesses-on-task-breakpoints.patch
ptrace-x86-simplify-the-disable-logic-in-ptrace_write_dr7.patch
ptrace-x86-dont-delay-disable-till-second-pass-in-ptrace_write_dr7.patch
ptrace-x86-introduce-ptrace_register_breakpoint.patch
ptrace-x86-ptrace_write_dr7-should-create-bp-if-disabled.patch
ptrace-x86-cleanup-ptrace_set_debugreg.patch
ptrace-ptrace_detach-should-do-flush_ptrace_hw_breakpointchild.patch
ptrace-x86-flush_ptrace_hw_breakpoint-shoule-clear-the-virtual-debug-registers.patch
x86-kill-tif_debug.patch
usermodehelper-kill-the-sub_info-path-check.patch
coredump-format_corename-can-leak-cn-corename.patch
coredump-introduce-cn_vprintf.patch
coredump-cn_vprintf-has-no-reason-to-call-vsnprintf-twice.patch
coredump-kill-cn_escape-introduce-cn_esc_printf.patch
coredump-kill-call_count-add-core_name_size.patch
coredump-%-at-the-end-shouldnt-bypass-core_uses_pid-logic.patch
fs-execc-do_execve_common-use-current_user.patch