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From: Pavel Machek <pavel@denx.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	Gerd Rausch <gerd.rausch@oracle.com>,
	Santosh Shilimkar <santosh.shilimkar@oracle.com>,
	Jakub Kicinski <kuba@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 4.9 12/16] net/rds: dma_map_sg is entitled to merge entries
Date: Fri, 3 Sep 2021 08:50:35 +0200	[thread overview]
Message-ID: <20210903065035.GA11871@amd> (raw)
In-Reply-To: <20210901122249.305212889@linuxfoundation.org>

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Hi!

> [ Upstream commit fb4b1373dcab086d0619c29310f0466a0b2ceb8a ]
> 
> Function "dma_map_sg" is entitled to merge adjacent entries
> and return a value smaller than what was passed as "nents".
> 
> Subsequently "ib_map_mr_sg" needs to work with this value ("sg_dma_len")
> rather than the original "nents" parameter ("sg_len").
> 
> This old RDS bug was exposed and reliably causes kernel panics
> (using RDMA operations "rds-stress -D") on x86_64 starting with:
> commit c588072bba6b ("iommu/vt-d: Convert intel iommu driver to the iommu ops")
> 
> Simply put: Linux 5.11 and later.

I see this queued for 4.19 and 5.10 where "iommu/vt-d: Convert intel
iommu driver to the iommu ops" is not present. It may be okay for
older kernels, too, but I wanted to double-check.

Best regards,
								Pavel

> +++ b/net/rds/ib_frmr.c
> @@ -112,9 +112,9 @@ static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
>  		cpu_relax();
>  	}
>  
> -	ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_len,
> +	ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len,
>  				&off, PAGE_SIZE);
> -	if (unlikely(ret != ibmr->sg_len))
> +	if (unlikely(ret != ibmr->sg_dma_len))
>  		return ret < 0 ? ret : -EINVAL;
>  
>  	/* Perform a WR for the fast_reg_mr. Each individual page

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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  reply	other threads:[~2021-09-03  6:50 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-01 12:26 [PATCH 4.9 00/16] 4.9.282-rc1 review Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 01/16] ARC: Fix CONFIG_STACKDEPOT Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 02/16] can: usb: esd_usb2: esd_usb2_rx_event(): fix the interchange of the CAN RX and TX error counters Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 03/16] Revert "USB: serial: ch341: fix character loss at high transfer rates" Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 04/16] USB: serial: option: add new VID/PID to support Fibocom FG150 Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 05/16] usb: dwc3: gadget: Fix dwc3_calc_trbs_left() Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 06/16] IB/hfi1: Fix possible null-pointer dereference in _extend_sdma_tx_descs() Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 07/16] e1000e: Fix the max snoop/no-snoop latency for 10M Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 08/16] ip_gre: add validation for csum_start Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 09/16] net: marvell: fix MVNETA_TX_IN_PRGRS bit number Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 10/16] virtio: Improve vq->broken access to avoid any compiler optimization Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 11/16] vringh: Use wiov->used to check for read/write desc order Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 12/16] net/rds: dma_map_sg is entitled to merge entries Greg Kroah-Hartman
2021-09-03  6:50   ` Pavel Machek [this message]
2021-09-03 16:02     ` Gerd Rausch
2021-09-01 12:26 ` [PATCH 4.9 13/16] vt_kdsetmode: extend console locking Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 14/16] fbmem: add margin check to fb_check_caps() Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 15/16] KVM: x86/mmu: Treat NX as used (not reserved) for all !TDP shadow MMUs Greg Kroah-Hartman
2021-09-01 12:26 ` [PATCH 4.9 16/16] Revert "floppy: reintroduce O_NDELAY fix" Greg Kroah-Hartman
2021-09-01 15:45 ` [PATCH 4.9 00/16] 4.9.282-rc1 review Florian Fainelli
2021-09-01 21:24 ` Shuah Khan
2021-09-02 16:10 ` Naresh Kamboju
2021-09-02 21:49 ` Guenter Roeck

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