• Leon Romanovsky's avatar
    RDMA/mlx5: Fix integer overflow while resizing CQ · 28e9091e
    Leon Romanovsky authored
    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>
    Cc: <stable@vger.kernel.org> # 3.13
    Fixes: bde51583 ("IB/mlx5: Add support for resize CQ")
    Reported-by: default avatarNoa Osherovich <noaos@mellanox.com>
    Reviewed-by: default avatarYishai Hadas <yishaih@mellanox.com>
    Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
    Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
    28e9091e
cq.c 35.3 KB