4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Leon Romanovsky leonro@mellanox.com
commit ae59c3f0b6cfd472fed96e50548a799b8971d876 upstream.
The rdma_ah_find_type() accesses the port array based on an index controlled by userspace. The existing bounds check is after the first use of the index, so userspace can generate an out of bounds access, as shown by the KASN report below.
================================================================== BUG: KASAN: slab-out-of-bounds in to_rdma_ah_attr+0xa8/0x3b0 Read of size 4 at addr ffff880019ae2268 by task ibv_rc_pingpong/409
CPU: 0 PID: 409 Comm: ibv_rc_pingpong Not tainted 4.15.0-rc2-00031-gb60a3faf5b83-dirty #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 Call Trace: dump_stack+0xe9/0x18f print_address_description+0xa2/0x350 kasan_report+0x3a5/0x400 to_rdma_ah_attr+0xa8/0x3b0 mlx5_ib_query_qp+0xd35/0x1330 ib_query_qp+0x8a/0xb0 ib_uverbs_query_qp+0x237/0x7f0 ib_uverbs_write+0x617/0xd80 __vfs_write+0xf7/0x500 vfs_write+0x149/0x310 SyS_write+0xca/0x190 entry_SYSCALL_64_fastpath+0x18/0x85 RIP: 0033:0x7fe9c7a275a0 RSP: 002b:00007ffee5498738 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe9c7ce4b00 RCX: 00007fe9c7a275a0 RDX: 0000000000000018 RSI: 00007ffee5498800 RDI: 0000000000000003 RBP: 000055d0c8d3f010 R08: 00007ffee5498800 R09: 0000000000000018 R10: 00000000000000ba R11: 0000000000000246 R12: 0000000000008000 R13: 0000000000004fb0 R14: 000055d0c8d3f050 R15: 00007ffee5498560
Allocated by task 1: __kmalloc+0x3f9/0x430 alloc_mad_private+0x25/0x50 ib_mad_post_receive_mads+0x204/0xa60 ib_mad_init_device+0xa59/0x1020 ib_register_device+0x83a/0xbc0 mlx5_ib_add+0x50e/0x5c0 mlx5_add_device+0x142/0x410 mlx5_register_interface+0x18f/0x210 mlx5_ib_init+0x56/0x63 do_one_initcall+0x15b/0x270 kernel_init_freeable+0x2d8/0x3d0 kernel_init+0x14/0x190 ret_from_fork+0x24/0x30
Freed by task 0: (stack is not available)
The buggy address belongs to the object at ffff880019ae2000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 104 bytes to the right of 512-byte region [ffff880019ae2000, ffff880019ae2200) The buggy address belongs to the page: page:000000005d674e18 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 0000000000000000 0000000000000000 00000001000c000c raw: dead000000000100 dead000000000200 ffff88001a402000 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff880019ae2100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff880019ae2180: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
ffff880019ae2200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^ ffff880019ae2280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff880019ae2300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Disabling lock debugging due to kernel taint
Fixes: 44c58487d51a ("IB/core: Define 'ib' and 'roce' rdma_ah_attr types") Signed-off-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/mlx5/qp.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
--- a/drivers/infiniband/hw/mlx5/qp.c +++ b/drivers/infiniband/hw/mlx5/qp.c @@ -4303,12 +4303,11 @@ static void to_rdma_ah_attr(struct mlx5_
memset(ah_attr, 0, sizeof(*ah_attr));
- ah_attr->type = rdma_ah_find_type(&ibdev->ib_dev, path->port); - rdma_ah_set_port_num(ah_attr, path->port); - if (rdma_ah_get_port_num(ah_attr) == 0 || - rdma_ah_get_port_num(ah_attr) > MLX5_CAP_GEN(dev, num_ports)) + if (!path->port || path->port > MLX5_CAP_GEN(dev, num_ports)) return;
+ ah_attr->type = rdma_ah_find_type(&ibdev->ib_dev, path->port); + rdma_ah_set_port_num(ah_attr, path->port); rdma_ah_set_sl(ah_attr, path->dci_cfi_prio_sl & 0xf);