Commit 89ede9d8 authored by YueHaibing's avatar YueHaibing Committed by Greg Kroah-Hartman

scsi: scsi_dh_alua: Fix possible null-ptr-deref

[ Upstream commit 12e750bc62044de096ab9a95201213fd912b9994 ]

If alloc_workqueue fails in alua_init, it should return -ENOMEM, otherwise
it will trigger null-ptr-deref while unloading module which calls
destroy_workqueue dereference
wq->lock like this:

BUG: KASAN: null-ptr-deref in __lock_acquire+0x6b4/0x1ee0
Read of size 8 at addr 0000000000000080 by task syz-executor.0/7045

CPU: 0 PID: 7045 Comm: syz-executor.0 Tainted: G         C        5.1.0+ #28
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
Call Trace:
 dump_stack+0xa9/0x10e
 __kasan_report+0x171/0x18d
 ? __lock_acquire+0x6b4/0x1ee0
 kasan_report+0xe/0x20
 __lock_acquire+0x6b4/0x1ee0
 lock_acquire+0xb4/0x1b0
 __mutex_lock+0xd8/0xb90
 drain_workqueue+0x25/0x290
 destroy_workqueue+0x1f/0x3f0
 __x64_sys_delete_module+0x244/0x330
 do_syscall_64+0x72/0x2a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Reported-by: 's avatarHulk Robot <hulkci@huawei.com>
Fixes: 03197b61 ("scsi_dh_alua: Use workqueue for RTPG")
Signed-off-by: 's avatarYueHaibing <yuehaibing@huawei.com>
Reviewed-by: 's avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: 's avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: 's avatarSasha Levin <sashal@kernel.org>
parent cb7c6c33
......@@ -1173,10 +1173,8 @@ static int __init alua_init(void)
int r;
kaluad_wq = alloc_workqueue("kaluad", WQ_MEM_RECLAIM, 0);
if (!kaluad_wq) {
/* Temporary failure, bypass */
return SCSI_DH_DEV_TEMP_BUSY;
}
if (!kaluad_wq)
return -ENOMEM;
r = scsi_register_device_handler(&alua_dh);
if (r != 0) {
......
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