| Message ID | 20170614103924.GK29394@elgon.mountain (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Wed, Jun 14, 2017 at 01:39:24PM +0300, Dan Carpenter wrote: > We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller > is expecting error pointers so it results in a NULL dereference. > > Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c > index 48332a6ed738..74a66cc162ed 100644 > --- a/net/rds/ib_frmr.c > +++ b/net/rds/ib_frmr.c > @@ -38,7 +38,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > struct rds_ib_mr_pool *pool; > struct rds_ib_mr *ibmr = NULL; > struct rds_ib_frmr *frmr; > - int err = 0; > + int err; Can we trust it'll be zero? > > if (npages <= RDS_MR_8K_MSG_SIZE) > pool = rds_ibdev->mr_8k_pool; > @@ -61,6 +61,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > pool->fmr_attr.max_pages); > if (IS_ERR(frmr->mr)) { > pr_warn("RDS/IB: %s failed to allocate MR", __func__); > + err = -ENOMEM; > goto out_no_cigar; > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jun 14, 2017 at 03:54:24PM +0300, Yuval Shaia wrote: > On Wed, Jun 14, 2017 at 01:39:24PM +0300, Dan Carpenter wrote: > > We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller > > is expecting error pointers so it results in a NULL dereference. > > > > Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c > > index 48332a6ed738..74a66cc162ed 100644 > > --- a/net/rds/ib_frmr.c > > +++ b/net/rds/ib_frmr.c > > @@ -38,7 +38,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > > struct rds_ib_mr_pool *pool; > > struct rds_ib_mr *ibmr = NULL; > > struct rds_ib_frmr *frmr; > > - int err = 0; > > + int err; > > Can we trust it'll be zero? We don't ever want it to be zero. This way, hopefully, GCC will catch it if we introduce any new bugs where we forget to set it to negative. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 14 Jun 2017, Yuval Shaia wrote: > On Wed, Jun 14, 2017 at 01:39:24PM +0300, Dan Carpenter wrote: > > We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller > > is expecting error pointers so it results in a NULL dereference. > > > > Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c > > index 48332a6ed738..74a66cc162ed 100644 > > --- a/net/rds/ib_frmr.c > > +++ b/net/rds/ib_frmr.c > > @@ -38,7 +38,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > > struct rds_ib_mr_pool *pool; > > struct rds_ib_mr *ibmr = NULL; > > struct rds_ib_frmr *frmr; > > - int err = 0; > > + int err; > > Can we trust it'll be zero? No need. With the change below there is always an assignment before the only reference at the end of the function. julia > > > > > if (npages <= RDS_MR_8K_MSG_SIZE) > > pool = rds_ibdev->mr_8k_pool; > > @@ -61,6 +61,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > > pool->fmr_attr.max_pages); > > if (IS_ERR(frmr->mr)) { > > pr_warn("RDS/IB: %s failed to allocate MR", __func__); > > + err = -ENOMEM; > > goto out_no_cigar; > > } > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jun 14, 2017 at 04:03:40PM +0300, Dan Carpenter wrote: > On Wed, Jun 14, 2017 at 03:54:24PM +0300, Yuval Shaia wrote: > > On Wed, Jun 14, 2017 at 01:39:24PM +0300, Dan Carpenter wrote: > > > We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller > > > is expecting error pointers so it results in a NULL dereference. > > > > > > Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") > > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > > > diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c > > > index 48332a6ed738..74a66cc162ed 100644 > > > --- a/net/rds/ib_frmr.c > > > +++ b/net/rds/ib_frmr.c > > > @@ -38,7 +38,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > > > struct rds_ib_mr_pool *pool; > > > struct rds_ib_mr *ibmr = NULL; > > > struct rds_ib_frmr *frmr; > > > - int err = 0; > > > + int err; > > > > Can we trust it'll be zero? > > We don't ever want it to be zero. This way, hopefully, GCC will catch > it if we introduce any new bugs where we forget to set it to negative. I see your point, in a "good" case we just return the ptr. Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com> > > regards, > dan carpenter > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6/14/17 3:39 AM, Dan Carpenter wrote: > We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller > is expecting error pointers so it results in a NULL dereference. > > Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > Thanks Dan for fix. Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> You haven't copied netdev. Can you please resend the patch with my ack on netdev so that Dave can pick it up. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Reviewed-by: Avinash Repaka <avinash.repaka@oracle.com> On 06/14/2017 03:39 AM, Dan Carpenter wrote: > We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller > is expecting error pointers so it results in a NULL dereference. > > Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c > index 48332a6ed738..74a66cc162ed 100644 > --- a/net/rds/ib_frmr.c > +++ b/net/rds/ib_frmr.c > @@ -38,7 +38,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > struct rds_ib_mr_pool *pool; > struct rds_ib_mr *ibmr = NULL; > struct rds_ib_frmr *frmr; > - int err = 0; > + int err; > > if (npages <= RDS_MR_8K_MSG_SIZE) > pool = rds_ibdev->mr_8k_pool; > @@ -61,6 +61,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, > pool->fmr_attr.max_pages); > if (IS_ERR(frmr->mr)) { > pr_warn("RDS/IB: %s failed to allocate MR", __func__); > + err = -ENOMEM; > goto out_no_cigar; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c index 48332a6ed738..74a66cc162ed 100644 --- a/net/rds/ib_frmr.c +++ b/net/rds/ib_frmr.c @@ -38,7 +38,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr_pool *pool; struct rds_ib_mr *ibmr = NULL; struct rds_ib_frmr *frmr; - int err = 0; + int err; if (npages <= RDS_MR_8K_MSG_SIZE) pool = rds_ibdev->mr_8k_pool; @@ -61,6 +61,7 @@ static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, pool->fmr_attr.max_pages); if (IS_ERR(frmr->mr)) { pr_warn("RDS/IB: %s failed to allocate MR", __func__); + err = -ENOMEM; goto out_no_cigar; }
We accidentally return ERR_PTR(0) if ib_alloc_mr() fails. The caller is expecting error pointers so it results in a NULL dereference. Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html