* [PATCH net 1/1] net/rds: dma_map_sg is entitled to merge entries
@ 2021-08-17 17:04 Gerd Rausch
2021-08-17 17:07 ` Santosh Shilimkar
2021-08-18 22:40 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Gerd Rausch @ 2021-08-17 17:04 UTC (permalink / raw)
To: Santosh Shilimkar, David S. Miller, Jakub Kicinski, netdev,
linux-rdma, rds-devel
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.
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
---
net/rds/ib_frmr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c
index 9b6ffff72f2d..28c1b0022178 100644
--- a/net/rds/ib_frmr.c
+++ b/net/rds/ib_frmr.c
@@ -131,9 +131,9 @@ 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;
if (cmpxchg(&frmr->fr_state,
--
2.24.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net 1/1] net/rds: dma_map_sg is entitled to merge entries
2021-08-17 17:04 [PATCH net 1/1] net/rds: dma_map_sg is entitled to merge entries Gerd Rausch
@ 2021-08-17 17:07 ` Santosh Shilimkar
2021-08-18 22:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Santosh Shilimkar @ 2021-08-17 17:07 UTC (permalink / raw)
To: Gerd Rausch
Cc: David S. Miller, Jakub Kicinski, netdev, linux-rdma, rds-devel
> On Aug 17, 2021, at 10:04 AM, Gerd Rausch <gerd.rausch@oracle.com> wrote:
>
> 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.
>
> Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
> ---
> net/rds/ib_frmr.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Looks good to me Gerd. Thanks !!
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net 1/1] net/rds: dma_map_sg is entitled to merge entries
2021-08-17 17:04 [PATCH net 1/1] net/rds: dma_map_sg is entitled to merge entries Gerd Rausch
2021-08-17 17:07 ` Santosh Shilimkar
@ 2021-08-18 22:40 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-08-18 22:40 UTC (permalink / raw)
To: Gerd Rausch; +Cc: santosh.shilimkar, davem, kuba, netdev, linux-rdma, rds-devel
Hello:
This patch was applied to netdev/net.git (refs/heads/master):
On Tue, 17 Aug 2021 10:04:37 -0700 you wrote:
> 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")
>
> [...]
Here is the summary with links:
- [net,1/1] net/rds: dma_map_sg is entitled to merge entries
https://git.kernel.org/netdev/net/c/fb4b1373dcab
You are awesome, thank you!
--
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2021-08-18 22:40 ` patchwork-bot+netdevbpf
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