Messages in this thread | | | Date | Fri, 28 Nov 2008 16:58:06 +0000 | From | Alan Cox <> | Subject | Re: [PATCH 3/4] add ksm kernel shared memory driver. |
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> + r = !memcmp(old_digest, sha1_item->sha1val, SHA1_DIGEST_SIZE); > + mutex_unlock(&sha1_lock); > + if (r) { > + char *old_addr, *new_addr; > + old_addr = kmap_atomic(oldpage, KM_USER0); > + new_addr = kmap_atomic(newpage, KM_USER1); > + r = !memcmp(old_addr+PAGEHASH_LEN, new_addr+PAGEHASH_LEN, > + PAGE_SIZE-PAGEHASH_LEN);
NAK - this isn't guaranteed to be robust so you could end up merging different pages one provided by a malicious attacker.
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