3.16.57-rc1 review patch. If anyone has any objections, please let me know.
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From: Leon Romanovsky leonro@mellanox.com
commit 28e9091e3119933c38933cb8fc48d5618eb784c8 upstream.
The user can provide very large cqe_size which will cause to integer overflow as it can be seen in the following UBSAN warning:
======================================================================= UBSAN: Undefined behaviour in drivers/infiniband/hw/mlx5/cq.c:1192:53 signed integer overflow: 64870 * 65536 cannot be represented in type 'int' CPU: 0 PID: 267 Comm: syzkaller605279 Not tainted 4.15.0+ #90 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+0xde/0x164 ? dma_virt_map_sg+0x22c/0x22c ubsan_epilogue+0xe/0x81 handle_overflow+0x1f3/0x251 ? __ubsan_handle_negate_overflow+0x19b/0x19b ? lock_acquire+0x440/0x440 mlx5_ib_resize_cq+0x17e7/0x1e40 ? cyc2ns_read_end+0x10/0x10 ? native_read_msr_safe+0x6c/0x9b ? cyc2ns_read_end+0x10/0x10 ? mlx5_ib_modify_cq+0x220/0x220 ? sched_clock_cpu+0x18/0x200 ? lookup_get_idr_uobject+0x200/0x200 ? rdma_lookup_get_uobject+0x145/0x2f0 ib_uverbs_resize_cq+0x207/0x3e0 ? ib_uverbs_ex_create_cq+0x250/0x250 ib_uverbs_write+0x7f9/0xef0 ? cyc2ns_read_end+0x10/0x10 ? print_irqtrace_events+0x280/0x280 ? ib_uverbs_ex_create_cq+0x250/0x250 ? uverbs_devnode+0x110/0x110 ? sched_clock_cpu+0x18/0x200 ? do_raw_spin_trylock+0x100/0x100 ? __lru_cache_add+0x16e/0x290 __vfs_write+0x10d/0x700 ? uverbs_devnode+0x110/0x110 ? kernel_read+0x170/0x170 ? sched_clock_cpu+0x18/0x200 ? security_file_permission+0x93/0x260 vfs_write+0x1b0/0x550 SyS_write+0xc7/0x1a0 ? SyS_read+0x1a0/0x1a0 ? trace_hardirqs_on_thunk+0x1a/0x1c entry_SYSCALL_64_fastpath+0x1e/0x8b RIP: 0033:0x433549 RSP: 002b:00007ffe63bd1ea8 EFLAGS: 00000217 =======================================================================
Cc: syzkaller syzkaller@googlegroups.com Fixes: bde51583f49b ("IB/mlx5: Add support for resize CQ") Reported-by: Noa Osherovich noaos@mellanox.com Reviewed-by: Yishai Hadas yishaih@mellanox.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/infiniband/hw/mlx5/cq.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/hw/mlx5/cq.c +++ b/drivers/infiniband/hw/mlx5/cq.c @@ -956,7 +956,12 @@ static int resize_user(struct mlx5_ib_de if (ucmd.reserved0 || ucmd.reserved1) return -EINVAL;
- umem = ib_umem_get(context, ucmd.buf_addr, entries * ucmd.cqe_size, + /* check multiplication overflow */ + if (ucmd.cqe_size && SIZE_MAX / ucmd.cqe_size <= entries - 1) + return -EINVAL; + + umem = ib_umem_get(context, ucmd.buf_addr, + (size_t)ucmd.cqe_size * entries, IB_ACCESS_LOCAL_WRITE, 1); if (IS_ERR(umem)) { err = PTR_ERR(umem);