From: Gerd Rausch gerd.rausch@oracle.com
[ 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 --- 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 3d9c4c6397c3..20d045faf07c 100644 --- a/net/rds/ib_frmr.c +++ 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