linux-kernel - [PATCH 4/9] xen/smp: Don't leak interrupt name when offlining.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1370447678-22367-5-git-send-email-konrad.wilk@oracle.com>
Date:	Wed,  5 Jun 2013 11:54:33 -0400
From:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
To:	xen-devel@...ts.xensource.com, linux-kernel@...r.kernel.org
Cc:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Subject: [PATCH 4/9] xen/smp: Don't leak interrupt name when offlining.

When the user does:
echo 0 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu1/online

kmemleak reports:
kmemleak: 7 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

unreferenced object 0xffff88003fa51240 (size 32):
  comm "swapper/0", pid 1, jiffies 4294667339 (age 1027.789s)
  hex dump (first 32 bytes):
    72 65 73 63 68 65 64 31 00 00 00 00 00 00 00 00  resched1........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81660721>] kmemleak_alloc+0x21/0x50
    [<ffffffff81190aac>] __kmalloc_track_caller+0xec/0x2a0
    [<ffffffff812fe1bb>] kvasprintf+0x5b/0x90
    [<ffffffff812fe228>] kasprintf+0x38/0x40
    [<ffffffff81047ed1>] xen_smp_intr_init+0x41/0x2c0
    [<ffffffff816636d3>] xen_cpu_up+0x393/0x3e8
    [<ffffffff8166bbf5>] _cpu_up+0xd1/0x14b
    [<ffffffff8166bd48>] cpu_up+0xd9/0xec
    [<ffffffff81ae6e4a>] smp_init+0x4b/0xa3
    [<ffffffff81ac4981>] kernel_init_freeable+0xdb/0x1e6
    [<ffffffff8165ce39>] kernel_init+0x9/0xf0
    [<ffffffff8167edfc>] ret_from_fork+0x7c/0xb0
    [<ffffffffffffffff>] 0xffffffffffffffff

This patch fixes some of it by using the 'struct xen_common_irq->name'
field to stash away the char so that it can be freed when
the interrupt line is destroyed.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
---
 arch/x86/xen/smp.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 6a483cd..37fbe71 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -107,19 +107,27 @@ static void xen_smp_intr_free(unsigned int cpu)
 	if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
 		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
 		per_cpu(xen_resched_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_resched_irq, cpu).name);
+		per_cpu(xen_resched_irq, cpu).name = NULL;
 	}
 	if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
 		unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
 		per_cpu(xen_callfunc_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_callfunc_irq, cpu).name);
+		per_cpu(xen_callfunc_irq, cpu).name = NULL;
 	}
 	if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
 		unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
 		per_cpu(xen_debug_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_debug_irq, cpu).name);
+		per_cpu(xen_debug_irq, cpu).name = NULL;
 	}
 	if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
 		unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
 				       NULL);
 		per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
+		per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
 	}
 	if (xen_hvm_domain())
 		return;
@@ -127,12 +135,14 @@ static void xen_smp_intr_free(unsigned int cpu)
 	if (per_cpu(xen_irq_work, cpu).irq >= 0) {
 		unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL);
 		per_cpu(xen_irq_work, cpu).irq = -1;
+		kfree(per_cpu(xen_irq_work, cpu).name);
+		per_cpu(xen_irq_work, cpu).name = NULL;
 	}
 };
 static int xen_smp_intr_init(unsigned int cpu)
 {
 	int rc;
-	const char *resched_name, *callfunc_name, *debug_name;
+	char *resched_name, *callfunc_name, *debug_name;
 
 	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
 	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
@@ -144,6 +154,7 @@ static int xen_smp_intr_init(unsigned int cpu)
 	if (rc < 0)
 		goto fail;
 	per_cpu(xen_resched_irq, cpu).irq = rc;
+	per_cpu(xen_resched_irq, cpu).name = resched_name;
 
 	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
 	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
@@ -155,6 +166,7 @@ static int xen_smp_intr_init(unsigned int cpu)
 	if (rc < 0)
 		goto fail;
 	per_cpu(xen_callfunc_irq, cpu).irq = rc;
+	per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 
 	debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
 	rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
@@ -163,6 +175,7 @@ static int xen_smp_intr_init(unsigned int cpu)
 	if (rc < 0)
 		goto fail;
 	per_cpu(xen_debug_irq, cpu).irq = rc;
+	per_cpu(xen_debug_irq, cpu).name = debug_name;
 
 	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
 	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
@@ -174,6 +187,7 @@ static int xen_smp_intr_init(unsigned int cpu)
 	if (rc < 0)
 		goto fail;
 	per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
+	per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
 
 	/*
 	 * The IRQ worker on PVHVM goes through the native path and uses the
@@ -192,6 +206,7 @@ static int xen_smp_intr_init(unsigned int cpu)
 	if (rc < 0)
 		goto fail;
 	per_cpu(xen_irq_work, cpu).irq = rc;
+	per_cpu(xen_irq_work, cpu).name = callfunc_name;
 
 	return 0;
 
-- 
1.8.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/