The iSCSI target driver is the only target driver that does not wait for
ongoing commands to finish before freeing a session. Make the iSCSI target
driver wait for ongoing commands to finish before freeing a session. This
patch fixes the following KASAN complaint:
BUG: KASAN: use-after-free in __lock_acquire+0xb1a/0x2710
Read of size 8 at addr ffff8881154eca70 by task kworker/0:2/247
CPU: 0 PID: 247 Comm: kworker/0:2 Not tainted 5.4.0-rc1-dbg+ #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Workqueue: target_completion target_complete_ok_work [target_core_mod]
Call Trace:
dump_stack+0x8a/0xd6
print_address_description.constprop.0+0x40/0x60
__kasan_report.cold+0x1b/0x33
kasan_report+0x16/0x20
__asan_load8+0x58/0x90
__lock_acquire+0xb1a/0x2710
lock_acquire+0xd3/0x200
_raw_spin_lock_irqsave+0x43/0x60
target_release_cmd_kref+0x162/0x7f0 [target_core_mod]
target_put_sess_cmd+0x2e/0x40 [target_core_mod]
lio_check_stop_free+0x12/0x20 [iscsi_target_mod]
transport_cmd_check_stop_to_fabric+0xd8/0xe0 [target_core_mod]
target_complete_ok_work+0x1b0/0x790 [target_core_mod]
process_one_work+0x549/0xa40
worker_thread+0x7a/0x5d0
kthread+0x1bc/0x210
ret_from_fork+0x24/0x30
Allocated by task 889:
save_stack+0x23/0x90
__kasan_kmalloc.constprop.0+0xcf/0xe0
kasan_slab_alloc+0x12/0x20
kmem_cache_alloc+0xf6/0x360
transport_alloc_session+0x29/0x80 [target_core_mod]
iscsi_target_login_thread+0xcd6/0x18f0 [iscsi_target_mod]
kthread+0x1bc/0x210
ret_from_fork+0x24/0x30
Freed by task 1025:
save_stack+0x23/0x90
__kasan_slab_free+0x13a/0x190
kasan_slab_free+0x12/0x20
kmem_cache_free+0x146/0x400
transport_free_session+0x179/0x2f0 [target_core_mod]
transport_deregister_session+0x130/0x180 [target_core_mod]
iscsit_close_session+0x12c/0x350 [iscsi_target_mod]
iscsit_logout_post_handler+0x136/0x380 [iscsi_target_mod]
iscsit_response_queue+0x8de/0xbe0 [iscsi_target_mod]
iscsi_target_tx_thread+0x27f/0x370 [iscsi_target_mod]
kthread+0x1bc/0x210
ret_from_fork+0x24/0x30
The buggy address belongs to the object at ffff8881154ec9c0
which belongs to the cache se_sess_cache of size 352
The buggy address is located 176 bytes inside of
352-byte region [ffff8881154ec9c0, ffff8881154ecb20)
The buggy address belongs to the page:
page:ffffea0004553b00 refcount:1 mapcount:0 mapping:ffff888101755400 index:0x0 compound_mapcount: 0
flags: 0x2fff000000010200(slab|head)
raw: 2fff000000010200 dead000000000100 dead000000000122 ffff888101755400
raw: 0000000000000000 0000000080130013 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881154ec900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881154ec980: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8881154eca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881154eca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881154ecb00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
Cc: Mike Christie <mchristi@redhat.com>
Link: https://lore.kernel.org/r/20191113220508.198257-3-bvanassche@acm.org
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
e9d3009cb9