Hi Steve,
I switch to using the softIWarp driver as there's a deadlock in the softRoCE
driver. However, this comes up with a repeatable UAF detected by KASAN.
The RDMA link was brought up with:
rdma link add siw0 type siw netdev enp6s0
and then I started running xfstests with -g quick.
MOUNT_OPTIONS -- -ordma,username=shares,password=...,mfsymlinks -o context=system_u:object_r:root_t:s0 //carina/scratch /xfstest.scratch
The kernel was v5.18 + iwarp SGE patch.
The KASAN splat is attached. Some decoded bits:
smbd_reconnect+0xba/0x1a6
smbd_reconnect (fs/cifs/smbdirect.c:1427):
if (server->smbd_conn->transport_status == SMBD_CONNECTED) {
_smbd_get_connection+0xce/0x1367
_smbd_get_connection (fs/cifs/smbdirect.c:1530):
info = kzalloc(sizeof(struct smbd_connection), GFP_KERNEL);
smbd_destroy+0x852/0x899
smbd_destroy (fs/cifs/smbdirect.c:1323):
(probably the kfree at the end on line 1407)
__cifs_reconnect+0x315/0x4b3
__cifs_reconnect (fs/cifs/connect.c:311 fs/cifs/connect.c:358)
smbd_destroy(server);
David
---
run fstests generic/005 at 2022-05-27 11:18:41
run fstests generic/006 at 2022-05-27 11:18:51
CIFS: VFS: smbd_recv_buf:1889 disconnected
==================================================================
BUG: KASAN: use-after-free in smbd_reconnect+0xba/0x1a6
Read of size 4 at addr ffff88813029e000 by task cifsd/4509
CPU: 2 PID: 4509 Comm: cifsd Not tainted 5.18.0-build2+ #467
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x59
print_address_description.constprop.0+0x1f/0x2ce
? smbd_reconnect+0xba/0x1a6
print_report+0xf0/0x1d6
? smbd_reconnect+0xba/0x1a6
? do_raw_spin_lock+0x13a/0x17b
? smbd_reconnect+0xba/0x1a6
kasan_report+0x81/0xa1
? smbd_reconnect+0xba/0x1a6
smbd_reconnect+0xba/0x1a6
__cifs_reconnect+0x351/0x4b3
? cifs_mark_tcp_ses_conns_for_reconnect+0x1b3/0x1b3
? __raw_spin_lock_init+0x85/0x85
cifs_readv_from_socket+0x29a/0x2f4
cifs_read_from_socket+0x95/0xc5
? cifs_readv_from_socket+0x2f4/0x2f4
? cifs_small_buf_get+0x50/0x5d
? allocate_buffers+0xfb/0x186
cifs_demultiplex_thread+0x19b/0xb64
? cifs_handle_standard+0x27e/0x27e
? lock_downgrade+0xad/0xad
? rcu_read_lock_bh_held+0xab/0xab
? pci_mmcfg_check_reserved+0xbd/0xbd
? preempt_count_sub+0x18/0xba
? _raw_spin_unlock_irqrestore+0x39/0x4c
? cifs_handle_standard+0x27e/0x27e
kthread+0x164/0x173
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x1f/0x30
</TASK>
Allocated by task 4505:
stack_trace_save+0x8f/0xbe
kasan_save_stack+0x1e/0x39
kasan_set_track+0x21/0x26
____kasan_kmalloc+0x68/0x72
kmem_cache_alloc_trace+0x121/0x162
_smbd_get_connection+0xce/0x1367
smbd_get_connection+0x21/0x3e
cifs_get_tcp_session.part.0+0x853/0xbda
mount_get_conns+0x51/0x594
cifs_mount+0x8d/0x279
cifs_smb3_do_mount+0x186/0x471
smb3_get_tree+0x58/0x91
vfs_get_tree+0x46/0x150
do_new_mount+0x19f/0x2c9
path_mount+0x6a5/0x6e3
do_mount+0x9e/0xe1
__do_sys_mount+0x150/0x17c
do_syscall_64+0x39/0x46
entry_SYSCALL_64_after_hwframe+0x44/0xae
Freed by task 4509:
stack_trace_save+0x8f/0xbe
kasan_save_stack+0x1e/0x39
kasan_set_track+0x21/0x26
kasan_set_free_info+0x20/0x2f
____kasan_slab_free+0xad/0xc9
kfree+0x125/0x14b
smbd_destroy+0x852/0x899
__cifs_reconnect+0x315/0x4b3
cifs_readv_from_socket+0x29a/0x2f4
cifs_read_from_socket+0x95/0xc5
cifs_demultiplex_thread+0x19b/0xb64
kthread+0x164/0x173
ret_from_fork+0x1f/0x30
Last potentially related work creation:
stack_trace_save+0x8f/0xbe
kasan_save_stack+0x1e/0x39
__kasan_record_aux_stack+0x62/0x68
insert_work+0x30/0xaf
__queue_work+0x4b9/0x4dc
queue_work_on+0x4d/0x67
__ib_process_cq+0x219/0x268
ib_poll_handler+0x3f/0x14c
irq_poll_softirq+0xd8/0x1ab
__do_softirq+0x202/0x489
Second to last potentially related work creation:
stack_trace_save+0x8f/0xbe
kasan_save_stack+0x1e/0x39
__kasan_record_aux_stack+0x62/0x68
insert_work+0x30/0xaf
__queue_work+0x4b9/0x4dc
queue_work_on+0x4d/0x67
recv_done+0x16f/0x727
__ib_process_cq+0x219/0x268
ib_poll_handler+0x3f/0x14c
irq_poll_softirq+0xd8/0x1ab
__do_softirq+0x202/0x489
The buggy address belongs to the object at ffff88813029e000
which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 0 bytes inside of
4096-byte region [ffff88813029e000, ffff88813029f000)
The buggy address belongs to the physical page:
page:0000000001f91160 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13029e
head:0000000001f91160 order:1 compound_mapcount:0 compound_pincount:0
flags: 0x200000000010200(slab|head|node=0|zone=2)
raw: 0200000000010200 ffffea0004c06d08 ffffea0004c0a288 ffff888100040900
raw: 0000000000000000 ffff88813029e000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88813029df00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88813029df80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88813029e000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88813029e080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88813029e100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Disabling lock debugging due to kernel taint
CIFS: VFS: RDMA transport re-established
CIFS: VFS: smbd_recv_buf:1889 disconnected
