Commits
Bart Van Assche committed c2852d1dc22
scsi: target: core: Release SPC-2 reservations when closing a session
[ Upstream commit 80647a89eaf3f2549741648f3230cd6ff68c23b4 ]
The SCSI specs require releasing SPC-2 reservations when a session is
closed. Make sure that the target core does this.
Running the libiscsi tests triggers the KASAN complaint shown below. This
patch fixes that use-after-free.
BUG: KASAN: use-after-free in target_check_reservation+0x171/0x980 [target_core_mod]
Read of size 8 at addr ffff88802ecd1878 by task iscsi_trx/17200
CPU: 0 PID: 17200 Comm: iscsi_trx Not tainted 5.4.0-rc1-dbg+ #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
dump_stack+0x8a/0xd6
print_address_description.constprop.0+0x40/0x60
__kasan_report.cold+0x1b/0x34
kasan_report+0x16/0x20
__asan_load8+0x58/0x90
target_check_reservation+0x171/0x980 [target_core_mod]
__target_execute_cmd+0xb1/0xf0 [target_core_mod]
target_execute_cmd+0x22d/0x4d0 [target_core_mod]
transport_generic_new_cmd+0x31f/0x5b0 [target_core_mod]
transport_handle_cdb_direct+0x6f/0x90 [target_core_mod]
iscsit_execute_cmd+0x381/0x3f0 [iscsi_target_mod]
iscsit_sequence_cmd+0x13b/0x1f0 [iscsi_target_mod]
iscsit_process_scsi_cmd+0x4c/0x130 [iscsi_target_mod]
iscsit_get_rx_pdu+0x8e8/0x15f0 [iscsi_target_mod]
iscsi_target_rx_thread+0x105/0x1b0 [iscsi_target_mod]
kthread+0x1bc/0x210
ret_from_fork+0x24/0x30
Allocated by task 1079:
save_stack+0x23/0x90
__kasan_kmalloc.constprop.0+0xcf/0xe0
kasan_slab_alloc+0x12/0x20
kmem_cache_alloc+0xfe/0x3a0
transport_alloc_session+0x29/0x80 [target_core_mod]
iscsi_target_login_thread+0xceb/0x1920 [iscsi_target_mod]
kthread+0x1bc/0x210
ret_from_fork+0x24/0x30
Freed by task 17193:
save_stack+0x23/0x90
__kasan_slab_free+0x13a/0x190
kasan_slab_free+0x12/0x20
kmem_cache_free+0xc8/0x3e0
transport_free_session+0x179/0x2f0 [target_core_mod]
transport_deregister_session+0x121/0x170 [target_core_mod]
iscsit_close_session+0x12c/0x350 [iscsi_target_mod]
iscsit_logout_post_handler+0x136/0x380 [iscsi_target_mod]
iscsit_response_queue+0x8fa/0xc00 [iscsi_target_mod]
iscsi_target_tx_thread+0x28e/0x390 [iscsi_target_mod]
kthread+0x1bc/0x210
ret_from_fork+0x24/0x30
The buggy address belongs to the object at ffff88802ecd1860
which belongs to the cache se_sess_cache of size 352
The buggy address is located 24 bytes inside of
352-byte region [ffff88802ecd1860, ffff88802ecd19c0)
The buggy address belongs to the page:
page:ffffea0000bb3400 refcount:1 mapcount:0 mapping:ffff8880bef2ed00 index:0x0 compound_mapcount: 0
flags: 0x1000000000010200(slab|head)
raw: 1000000000010200 dead000000000100 dead000000000122 ffff8880bef2ed00
raw: 0000000000000000 0000000080270027 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88802ecd1700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802ecd1780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802ecd1800: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb
^
ffff88802ecd1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802ecd1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Cc: Mike Christie <mchristi@redhat.com>
Link: https://lore.kernel.org/r/20191113220508.198257-2-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>
Signed-off-by: Sasha Levin <sashal@kernel.org>