[LU-20197] bogus memcpy in lod_layout_repeat_comp()

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Severity: 3
• Assignee: Sohei Koyama
• Reporter: Sohei Koyama

Description

In lod_layout_repeat_comp() (lustre/lod/lod_object.c:4811):

    if (new_comp->llc_ostlist.op_array) {
        __u32 *op_array = NULL;
        OBD_ALLOC(op_array, new_comp->llc_ostlist.op_size);
        if (!op_array)
            GOTO(out, rc = -ENOMEM);
        memcpy(op_array, &new_comp->llc_ostlist.op_array, // trim & is correct
               new_comp->llc_ostlist.op_size);
        new_comp->llc_ostlist.op_array = op_array;
    } 

It seems triggered only when an SEL component with an explicit OST list (lfs setstripe -o) exhausts its extension space and is repeated into a new component.

 Found by code inspection.