2022-08-31 09:15:04

by Xiao Yang

[permalink] [raw]
Subject: [PATCH v2] 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: ad215aaea4f9 ("RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent")
Signed-off-by: Xiao Yang <[email protected]>
---
drivers/infiniband/ulp/srp/ib_srp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 7720ea270ed8..d7f69e593a63 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1961,7 +1961,8 @@ 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);
- } else {
+ }
+ if (!scmnd) {
shost_printk(KERN_ERR, target->scsi_host,
"Null scmnd for RSP w/tag %#016llx received on ch %td / QP %#x\n",
rsp->tag, ch - target->ch, ch->qp->qp_num);
--
2.34.1


2022-08-31 14:35:36

by Bart Van Assche

[permalink] [raw]
Subject: Re: [PATCH v2] RDMA/srp: Set scmnd->result only when scmnd is not NULL

On 8/31/22 01:16, [email protected] wrote:
> This change fixes the following kernel NULL pointer dereference
> which is reproduced by blktests srp/007 occasionally.

Acked-by: Bart Van Assche <[email protected]>

2022-09-01 07:45:29

by Leon Romanovsky

[permalink] [raw]
Subject: Re: [PATCH v2] RDMA/srp: Set scmnd->result only when scmnd is not NULL

On Wed, Aug 31, 2022 at 08:16:29AM +0000, [email protected] wrote:
> 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: ad215aaea4f9 ("RDMA/srp: Make struct scsi_cmnd and struct srp_request adjacent")
> Signed-off-by: Xiao Yang <[email protected]>
> ---
> drivers/infiniband/ulp/srp/ib_srp.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>

Thanks, applied.