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On 29 Jul 2013 at 6:23, Javier Juan Martínez Cabezón wrote: |
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> PaX tries to do this modification to rsbac git code: |
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> |
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> --- fs/namei.c 2013-03-19 01:53:21.091281869 +0100 |
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> +++ fs/namei.c 2013-03-19 01:53:31.251281326 +0100 |
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> @@ -3954,7 +3956,14 @@ |
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> len = strlen(link); |
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> if (len > (unsigned) buflen) |
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> len = buflen; |
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> - if (copy_to_user(buffer, link, len)) |
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> + |
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> + if (len < sizeof(tmpbuf)) { |
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> + memcpy(tmpbuf, link, len); |
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> + newlink = tmpbuf; |
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> + } else |
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> + newlink = link; |
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> + |
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> + if (copy_to_user(buffer, newlink, len)) |
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> len = -EFAULT; |
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> out: |
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> return len; |
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|
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this change is done for USERCOPY to prevent false positive reports when the |
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name comes from a dentry field (vs. a normal kmalloc slab) or something |
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like that. if you want to enable USERCOPY under RSBAC as well then you'll |
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have to ensure that either rsbac_name is allocated by a normal kmalloc (this |
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seems to be the case already from a quick look) or you'll have to do the |
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temporary stack copy as done in the above snippet. |
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