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authorGerd Rausch <gerd.rausch@oracle.com>2021-08-17 10:04:37 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-03 10:08:15 +0200
commitf3a1ac258ebcb741e04623b2329bd9a9582d7fcf (patch)
tree30c1558d659f34fa4eb89056b0b2caa8290a9d0e
parentad6a2bc7588ac0e217a72e2feedb5c0c360b2f96 (diff)
net/rds: dma_map_sg is entitled to merge entries
[ 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. Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Link: https://lore.kernel.org/r/60efc69f-1f35-529d-a7ef-da0549cad143@oracle.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--net/rds/ib_frmr.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c
index 06ecf9d2d4bf..ef6acd721118 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,