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authorNick Black <nlb@google.com>2019-12-26 15:31:48 -0500
committerMartin K. Petersen <martin.petersen@oracle.com>2020-01-15 22:48:34 -0500
commit54155ed4199c7aa3fd20866648024ab63c96d579 (patch)
tree57180674c7d893ef6b909e0f3bb607ab10d66230
parentea92c32bd336efba89c5b09cf609e6e26e963796 (diff)
scsi: iscsi: Don't destroy session if there are outstanding connections
A faulty userspace that calls destroy_session() before destroying the connections can trigger the failure. This patch prevents the issue by refusing to destroy the session if there are outstanding connections. ------------[ cut here ]------------ kernel BUG at mm/slub.c:306! invalid opcode: 0000 [#1] SMP PTI CPU: 1 PID: 1224 Comm: iscsid Not tainted 5.4.0-rc2.iscsi+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__slab_free+0x181/0x350 [...] [ 1209.686056] RSP: 0018:ffffa93d4074fae0 EFLAGS: 00010246 [ 1209.686694] RAX: ffff934efa5ad800 RBX: 000000008010000a RCX: ffff934efa5ad800 [ 1209.687651] RDX: ffff934efa5ad800 RSI: ffffeb4041e96b00 RDI: ffff934efd402c40 [ 1209.688582] RBP: ffffa93d4074fb80 R08: 0000000000000001 R09: ffffffffbb5dfa26 [ 1209.689425] R10: ffff934efa5ad800 R11: 0000000000000001 R12: ffffeb4041e96b00 [ 1209.690285] R13: ffff934efa5ad800 R14: ffff934efd402c40 R15: 0000000000000000 [ 1209.691213] FS: 00007f7945dfb540(0000) GS:ffff934efda80000(0000) knlGS:0000000000000000 [ 1209.692316] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1209.693013] CR2: 000055877fd3da80 CR3: 0000000077384000 CR4: 00000000000006e0 [ 1209.693897] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1209.694773] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 1209.695631] Call Trace: [ 1209.695957] ? __wake_up_common_lock+0x8a/0xc0 [ 1209.696712] iscsi_pool_free+0x26/0x40 [ 1209.697263] iscsi_session_teardown+0x2f/0xf0 [ 1209.698117] iscsi_sw_tcp_session_destroy+0x45/0x60 [ 1209.698831] iscsi_if_rx+0xd88/0x14e0 [ 1209.699370] netlink_unicast+0x16f/0x200 [ 1209.699932] netlink_sendmsg+0x21a/0x3e0 [ 1209.700446] sock_sendmsg+0x4f/0x60 [ 1209.700902] ___sys_sendmsg+0x2ae/0x320 [ 1209.701451] ? cp_new_stat+0x150/0x180 [ 1209.701922] __sys_sendmsg+0x59/0xa0 [ 1209.702357] do_syscall_64+0x52/0x160 [ 1209.702812] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1209.703419] RIP: 0033:0x7f7946433914 [...] [ 1209.706084] RSP: 002b:00007fffb99f2378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1209.706994] RAX: ffffffffffffffda RBX: 000055bc869eac20 RCX: 00007f7946433914 [ 1209.708082] RDX: 0000000000000000 RSI: 00007fffb99f2390 RDI: 0000000000000005 [ 1209.709120] RBP: 00007fffb99f2390 R08: 000055bc84fe9320 R09: 00007fffb99f1f07 [ 1209.710110] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000038 [ 1209.711085] R13: 000055bc8502306e R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace a2d933ede7f730d8 ]--- Link: https://lore.kernel.org/r/20191226203148.2172200-1-krisman@collabora.com Signed-off-by: Nick Black <nlb@google.com> Co-developed-by: Salman Qazi <sqazi@google.com> Signed-off-by: Salman Qazi <sqazi@google.com> Co-developed-by: Junho Ryu <jayr@google.com> Signed-off-by: Junho Ryu <jayr@google.com> Co-developed-by: Khazhismel Kumykov <khazhy@google.com> Signed-off-by: Khazhismel Kumykov <khazhy@google.com> Co-developed-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
-rw-r--r--drivers/scsi/iscsi_tcp.c4
-rw-r--r--drivers/scsi/scsi_transport_iscsi.c26
2 files changed, 27 insertions, 3 deletions
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 0bc63a7ab41c..b5dd1caae5e9 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -887,6 +887,10 @@ free_host:
static void iscsi_sw_tcp_session_destroy(struct iscsi_cls_session *cls_session)
{
struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
+ struct iscsi_session *session = cls_session->dd_data;
+
+ if (WARN_ON_ONCE(session->leadconn))
+ return;
iscsi_tcp_r2tpool_free(cls_session->dd_data);
iscsi_session_teardown(cls_session);
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index ed8d9709b9b9..271afea654e2 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -2947,6 +2947,24 @@ iscsi_set_path(struct iscsi_transport *transport, struct iscsi_uevent *ev)
return err;
}
+static int iscsi_session_has_conns(int sid)
+{
+ struct iscsi_cls_conn *conn;
+ unsigned long flags;
+ int found = 0;
+
+ spin_lock_irqsave(&connlock, flags);
+ list_for_each_entry(conn, &connlist, conn_list) {
+ if (iscsi_conn_get_sid(conn) == sid) {
+ found = 1;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&connlock, flags);
+
+ return found;
+}
+
static int
iscsi_set_iface_params(struct iscsi_transport *transport,
struct iscsi_uevent *ev, uint32_t len)
@@ -3524,10 +3542,12 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
break;
case ISCSI_UEVENT_DESTROY_SESSION:
session = iscsi_session_lookup(ev->u.d_session.sid);
- if (session)
- transport->destroy_session(session);
- else
+ if (!session)
err = -EINVAL;
+ else if (iscsi_session_has_conns(ev->u.d_session.sid))
+ err = -EBUSY;
+ else
+ transport->destroy_session(session);
break;
case ISCSI_UEVENT_UNBIND_SESSION:
session = iscsi_session_lookup(ev->u.d_session.sid);