linux-kernel - [PATCH] RDMA/srp: Set scmnd->result only when scmnd is not NULL

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220831014730.17566-1-yangx.jy@fujitsu.com>
Date:   Wed, 31 Aug 2022 01:47:34 +0000
From:   "yangx.jy@...itsu.com" <yangx.jy@...itsu.com>
To:     "bvanassche@....org" <bvanassche@....org>,
        "jgg@...dia.com" <jgg@...dia.com>,
        "leon@...nel.org" <leon@...nel.org>
CC:     "linux-rdma@...r.kernel.org" <linux-rdma@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "yangx.jy@...itsu.com" <yangx.jy@...itsu.com>
Subject: [PATCH] RDMA/srp: Set scmnd->result only when scmnd is not NULL

This change fixes the following kernel NULL pointer dereference
which is reproduced by blktests srp/007 occasionally.

BUG: kernel NULL pointer dereference, address: 0000000000000170
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 9 Comm: kworker/0:1H Kdump: loaded Not tainted 6.0.0-rc1+ #37
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-29-g6a62e0cb0dfe-prebuilt.qemu.org 04/01/2014
Workqueue:  0x0 (kblockd)
RIP: 0010:srp_recv_done+0x176/0x500 [ib_srp]
Code: 00 4d 85 ff 0f 84 52 02 00 00 48 c7 82 80 02 00 00 00 00 00 00 4c 89 df 4c 89 14 24 e8 53 d3 4a f6 4c 8b 14 24 41 0f b6 42 13 <41> 89 87 70 01 00 00 41 0f b6 52 12 f6 c2 02 74 44 41 8b 42 1c b9
RSP: 0018:ffffaef7c0003e28 EFLAGS: 00000282
RAX: 0000000000000000 RBX: ffff9bc9486dea60 RCX: 0000000000000000
RDX: 0000000000000102 RSI: ffffffffb76bbd0e RDI: 00000000ffffffff
RBP: ffff9bc980099a00 R08: 0000000000000001 R09: 0000000000000001
R10: ffff9bca53ef0000 R11: ffff9bc980099a10 R12: ffff9bc956e14000
R13: ffff9bc9836b9cb0 R14: ffff9bc9557b4480 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff9bc97ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 0000000007e04000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __ib_process_cq+0xb7/0x280 [ib_core]
 ib_poll_handler+0x2b/0x130 [ib_core]
 irq_poll_softirq+0x93/0x150
 __do_softirq+0xee/0x4b8
 irq_exit_rcu+0xf7/0x130
 sysvec_apic_timer_interrupt+0x8e/0xc0
 </IRQ>

Fixes: aef9ec39c47f ("IB: Add SCSI RDMA Protocol (SRP) initiator")
Signed-off-by: Xiao Yang <yangx.jy@...itsu.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 7720ea270ed8..528cdd0daba4 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1961,6 +1961,7 @@ static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
 		if (scmnd) {
 			req = scsi_cmd_priv(scmnd);
 			scmnd = srp_claim_req(ch, req, NULL, scmnd);
+			scmnd->result = rsp->status;
 		} else {
 			shost_printk(KERN_ERR, target->scsi_host,
 				     "Null scmnd for RSP w/tag %#016llx received on ch %td / QP %#x\n",
@@ -1972,7 +1973,6 @@ static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)
 
 			return;
 		}
-		scmnd->result = rsp->status;
 
 		if (rsp->flags & SRP_RSP_FLAG_SNSVALID) {
 			memcpy(scmnd->sense_buffer, rsp->data +
-- 
2.34.1