The "struct mana_cfg_rx_steer_req_v2" uses a dynamically sized set of trailing elements. Specifically, it uses a "mana_handle_t" array. So, use the preferred way in the kernel declaring a flexible array [1]. At the same time, prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). Also, avoid the open-coded arithmetic in the memory allocator functions [2] using the "struct_size" macro. Moreover, use the "offsetof" helper to get the indirect table offset instead of the "sizeof" operator and avoid the open-coded arithmetic in pointers using the new flex member. This new structure member also allow us to remove the "req_indir_tab" variable since it is no longer needed. Now, it is also possible to use the "flex_array_size" helper to compute the size of these trailing elements in the "memcpy" function. This code was detected with the help of Coccinelle, and audited and modified manually. Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero-length-and-one-element-arrays [1] Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments [2] Signed-off-by: Erick Archer <erick.archer@xxxxxxxxxxx> --- Changes in v2: - Remove the "req_indir_tab" variable (Gustavo A. R. Silva). - Update the commit message. - Add the "__counted_by" attribute. Previous versions: v1 -> https://lore.kernel.org/linux-hardening/AS8PR02MB7237974EF1B9BAFA618166C38B382@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Hi, The Coccinelle script used to detect this code pattern is the following: virtual report @rule1@ type t1; type t2; identifier i0; identifier i1; identifier i2; identifier ALLOC =~ "kmalloc|kzalloc|kmalloc_node|kzalloc_node|vmalloc|vzalloc|kvmalloc|kvzalloc"; position p1; @@ i0 = sizeof(t1) + sizeof(t2) * i1; ... i2 = ALLOC@p1(..., i0, ...); @script:python depends on report@ p1 << rule1.p1; @@ msg = "WARNING: verify allocation on line %s" % (p1[0].line) coccilib.report.print_report(p1[0],msg) Regards, Erick --- drivers/infiniband/hw/mana/qp.c | 12 +++++------- drivers/net/ethernet/microsoft/mana/mana_en.c | 14 ++++++-------- include/net/mana/mana.h | 1 + 3 files changed, 12 insertions(+), 15 deletions(-) diff --git a/drivers/infiniband/hw/mana/qp.c b/drivers/infiniband/hw/mana/qp.c index 6e7627745c95..258f89464c10 100644 --- a/drivers/infiniband/hw/mana/qp.c +++ b/drivers/infiniband/hw/mana/qp.c @@ -15,15 +15,13 @@ static int mana_ib_cfg_vport_steering(struct mana_ib_dev *dev, struct mana_port_context *mpc = netdev_priv(ndev); struct mana_cfg_rx_steer_req_v2 *req; struct mana_cfg_rx_steer_resp resp = {}; - mana_handle_t *req_indir_tab; struct gdma_context *gc; u32 req_buf_size; int i, err; gc = mdev_to_gc(dev); - req_buf_size = - sizeof(*req) + sizeof(mana_handle_t) * MANA_INDIRECT_TABLE_SIZE; + req_buf_size = struct_size(req, indir_tab, MANA_INDIRECT_TABLE_SIZE); req = kzalloc(req_buf_size, GFP_KERNEL); if (!req) return -ENOMEM; @@ -44,20 +42,20 @@ static int mana_ib_cfg_vport_steering(struct mana_ib_dev *dev, req->rss_enable = true; req->num_indir_entries = MANA_INDIRECT_TABLE_SIZE; - req->indir_tab_offset = sizeof(*req); + req->indir_tab_offset = offsetof(struct mana_cfg_rx_steer_req_v2, + indir_tab); req->update_indir_tab = true; req->cqe_coalescing_enable = 1; - req_indir_tab = (mana_handle_t *)(req + 1); /* The ind table passed to the hardware must have * MANA_INDIRECT_TABLE_SIZE entries. Adjust the verb * ind_table to MANA_INDIRECT_TABLE_SIZE if required */ ibdev_dbg(&dev->ib_dev, "ind table size %u\n", 1 << log_ind_tbl_size); for (i = 0; i < MANA_INDIRECT_TABLE_SIZE; i++) { - req_indir_tab[i] = ind_table[i % (1 << log_ind_tbl_size)]; + req->indir_tab[i] = ind_table[i % (1 << log_ind_tbl_size)]; ibdev_dbg(&dev->ib_dev, "index %u handle 0x%llx\n", i, - req_indir_tab[i]); + req->indir_tab[i]); } req->update_hashkey = true; diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 59287c6e6cee..62bf3e5661a6 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -1058,11 +1058,10 @@ static int mana_cfg_vport_steering(struct mana_port_context *apc, struct mana_cfg_rx_steer_req_v2 *req; struct mana_cfg_rx_steer_resp resp = {}; struct net_device *ndev = apc->ndev; - mana_handle_t *req_indir_tab; u32 req_buf_size; int err; - req_buf_size = sizeof(*req) + sizeof(mana_handle_t) * num_entries; + req_buf_size = struct_size(req, indir_tab, num_entries); req = kzalloc(req_buf_size, GFP_KERNEL); if (!req) return -ENOMEM; @@ -1074,7 +1073,8 @@ static int mana_cfg_vport_steering(struct mana_port_context *apc, req->vport = apc->port_handle; req->num_indir_entries = num_entries; - req->indir_tab_offset = sizeof(*req); + req->indir_tab_offset = offsetof(struct mana_cfg_rx_steer_req_v2, + indir_tab); req->rx_enable = rx; req->rss_enable = apc->rss_state; req->update_default_rxobj = update_default_rxobj; @@ -1086,11 +1086,9 @@ static int mana_cfg_vport_steering(struct mana_port_context *apc, if (update_key) memcpy(&req->hashkey, apc->hashkey, MANA_HASH_KEY_SIZE); - if (update_tab) { - req_indir_tab = (mana_handle_t *)(req + 1); - memcpy(req_indir_tab, apc->rxobj_table, - req->num_indir_entries * sizeof(mana_handle_t)); - } + if (update_tab) + memcpy(req->indir_tab, apc->rxobj_table, + flex_array_size(req, indir_tab, req->num_indir_entries)); err = mana_send_request(apc->ac, req, req_buf_size, &resp, sizeof(resp)); diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index 76147feb0d10..46f741ebce21 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -671,6 +671,7 @@ struct mana_cfg_rx_steer_req_v2 { u8 hashkey[MANA_HASH_KEY_SIZE]; u8 cqe_coalescing_enable; u8 reserved2[7]; + mana_handle_t indir_tab[] __counted_by(num_indir_entries); }; /* HW DATA */ struct mana_cfg_rx_steer_resp { -- 2.25.1
