[PATCH AUTOSEL 4.19 56/60] scsi: qedi: Check targetname while finding boot target information

Sasha Levin
2019-06-27T00:39:17Z

From: Nilesh Javali <njavali@marvell.com>

[ Upstream commit 1ac3549ed58cdfdaf43bbf31ac260e2381cc0dae ]

The kernel panic was observed during iSCSI discovery via offload with below
call trace,

[ 2115.646901] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 2115.646909] IP: [<ffffffffacf7f0cc>] strncmp+0xc/0x60
[ 2115.646927] PGD 0
[ 2115.646932] Oops: 0000 [#1] SMP
[ 2115.647107] CPU: 24 PID: 264 Comm: kworker/24:1 Kdump: loaded Tainted: G
OE ------------ 3.10.0-957.el7.x86_64 #1
[ 2115.647133] Workqueue: slowpath-13:00. qed_slowpath_task [qed]
[ 2115.647135] task: ffff8d66af80b0c0 ti: ffff8d66afb80000 task.ti: ffff8d66afb80000
[ 2115.647136] RIP: 0010:[<ffffffffacf7f0cc>] [<ffffffffacf7f0cc>] strncmp+0xc/0x60
[ 2115.647141] RSP: 0018:ffff8d66afb83c68 EFLAGS: 00010206
[ 2115.647143] RAX: 0000000000000001 RBX: 0000000000000007 RCX: 000000000000000a
[ 2115.647144] RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8d632b3ba040
[ 2115.647145] RBP: ffff8d66afb83c68 R08: 0000000000000000 R09: 000000000000ffff
[ 2115.647147] R10: 0000000000000007 R11: 0000000000000800 R12: ffff8d66a30007a0
[ 2115.647148] R13: ffff8d66747a3c10 R14: ffff8d632b3ba000 R15: ffff8d66747a32f8
[ 2115.647149] FS: 0000000000000000(0000) GS:ffff8d66aff00000(0000) knlGS:0000000000000000
[ 2115.647151] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2115.647152] CR2: 0000000000000000 CR3: 0000000509610000 CR4: 00000000007607e0
[ 2115.647153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2115.647154] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2115.647155] PKRU: 00000000
[ 2115.647157] Call Trace:
[ 2115.647165] [<ffffffffc0634cc5>] qedi_get_protocol_tlv_data+0x2c5/0x510 [qedi]
[ 2115.647184] [<ffffffffc05968f5>] ? qed_mfw_process_tlv_req+0x245/0xbe0 [qed]
[ 2115.647195] [<ffffffffc05496cb>] qed_mfw_fill_tlv_data+0x4b/0xb0 [qed]
[ 2115.647206] [<ffffffffc0596911>] qed_mfw_process_tlv_req+0x261/0xbe0 [qed]
[ 2115.647215] [<ffffffffacce0e8e>] ? dequeue_task_fair+0x41e/0x660
[ 2115.647221] [<ffffffffacc2a59e>] ? __switch_to+0xce/0x580
[ 2115.647230] [<ffffffffc0546013>] qed_slowpath_task+0xa3/0x160 [qed]
[ 2115.647278] RIP [<ffffffffacf7f0cc>] strncmp+0xc/0x60

Fix kernel panic by validating the session targetname before providing TLV
data and confirming the presence of boot targets.

Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/qedi/qedi_main.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index 4de740da547b..763c7628356b 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -955,6 +955,9 @@ static int qedi_find_boot_info(struct qedi_ctx *qedi,
if (!iscsi_is_session_online(cls_sess))
continue;

+ if (!sess->targetname)
+ continue;
+
if (pri_ctrl_flags) {
if (!strcmp(pri_tgt->iscsi_name, sess->targetname) &&
!strcmp(pri_tgt->ip_addr, ep_ip_addr)) {
--
2.20.1