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authorJason Yan <yanaijie@huawei.com>2018-05-10 05:05:16 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2018-06-20 04:02:25 +0200
commit2fa4a32613c9182b00e46872755b0662374424a7 (patch)
tree79b70b0062d7c95c9b0eecca9ae8e15c06780b7e /drivers/scsi/libsas/sas_discover.c
parentscsi: Remove percpu_ida (diff)
downloadlinux-2fa4a32613c9182b00e46872755b0662374424a7.tar.xz
linux-2fa4a32613c9182b00e46872755b0662374424a7.zip
scsi: libsas: dynamically allocate and free ata host
Commit 2623c7a5f2 ("libata: add refcounting to ata_host") v4.17+ introduced refcounting to ata_host and will increase or decrease the refcount when adding or deleting transport ATA port. Now the ata host for libsas is embedded in domain_device, and the ->kref member is not initialized. Afer we add ata transport class, ata_host_get() will be called when adding transport ATA port and a warning will be triggered as below: refcount_t: increment on 0; use-after-free. WARNING: CPU: 2 PID: 103 at lib/refcount.c:153 refcount_inc+0x40/0x48 ...... Call trace: refcount_inc+0x40/0x48 ata_host_get+0x10/0x18 ata_tport_add+0x40/0x120 ata_sas_tport_add+0xc/0x14 sas_ata_init+0x7c/0xc8 sas_discover_domain+0x380/0x53c process_one_work+0x12c/0x288 worker_thread+0x58/0x3f0 kthread+0xfc/0x128 ret_from_fork+0x10/0x18 And also when removing transport ATA port ata_host_put() will be called and another similar warning will be triggered. If the refcount decreased to zero, the ata host will be freed. But this ata host is only part of domain_device, it cannot be freed directly. So we have to change this embedded static ata host to a dynamically allocated ata host and initialize the ->kref member. To use ata_host_get() and ata_host_put() in libsas, we need to move the declaration of these functions to the public libata.h and export them. Fixes: b6240a4df018 ("scsi: libsas: add transport class for ATA devices") Signed-off-by: Jason Yan <yanaijie@huawei.com> CC: John Garry <john.garry@huawei.com> CC: Taras Kondratiuk <takondra@cisco.com> CC: Tejun Heo <tj@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/libsas/sas_discover.c')
-rw-r--r--drivers/scsi/libsas/sas_discover.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 1ffca28fe6a8..0148ae62a52a 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -316,6 +316,8 @@ void sas_free_device(struct kref *kref)
if (dev_is_sata(dev) && dev->sata_dev.ap) {
ata_sas_tport_delete(dev->sata_dev.ap);
ata_sas_port_destroy(dev->sata_dev.ap);
+ ata_host_put(dev->sata_dev.ata_host);
+ dev->sata_dev.ata_host = NULL;
dev->sata_dev.ap = NULL;
}