From: JeffleXu <jefflexu@linux.alibaba.com> To: David Howells <dhowells@redhat.com>, linux-cachefs@redhat.com Cc: Trond Myklebust <trondmy@hammerspace.com>, Anna Schumaker <anna.schumaker@netapp.com>, Steve French <sfrench@samba.org>, Dominique Martinet <asmadeus@codewreck.org>, Jeff Layton <jlayton@kernel.org>, Matthew Wilcox <willy@infradead.org>, Alexander Viro <viro@zeniv.linux.org.uk>, Omar Sandoval <osandov@osandov.com>, Linus Torvalds <torvalds@linux-foundation.org>, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 44/64] cachefiles: Implement key to filename encoding Date: Wed, 1 Dec 2021 13:46:02 +0800 [thread overview] Message-ID: <bcefb8f2-576a-b3fc-cc29-89808ebfd7c1@linux.alibaba.com> (raw) In-Reply-To: <163819640393.215744.15212364106412961104.stgit@warthog.procyon.org.uk> On 11/29/21 10:33 PM, David Howells wrote: > +/* > + * turn the raw key into something cooked > + * - the key may be up to NAME_MAX in length (including the length word) > + * - "base64" encode the strange keys, mapping 3 bytes of raw to four of > + * cooked > + * - need to cut the cooked key into 252 char lengths (189 raw bytes) > + */ > +bool cachefiles_cook_key(struct cachefiles_object *object) > +{ > + const u8 *key = fscache_get_key(object->cookie), *kend; > + unsigned char ch; > + unsigned int acc, i, n, nle, nbe, keylen = object->cookie->key_len; > + unsigned int b64len, len, print, pad; > + char *name, sep; > + > + _enter(",%u,%*phN", keylen, keylen, key); > + > + BUG_ON(keylen > NAME_MAX - 3); > + > + print = 1; > + for (i = 0; i < keylen; i++) { > + ch = key[i]; > + print &= cachefiles_filecharmap[ch]; > + } > + > + /* If the path is usable ASCII, then we render it directly */ > + if (print) { > + len = 1 + keylen + 1; > + name = kmalloc(len, GFP_KERNEL); > + if (!name) > + return false; > + > + name[0] = 'D'; /* Data object type, string encoding */ > + name[1 + keylen] = 0; > + memcpy(name + 1, key, keylen); > + goto success; ^ If we goto success from here, > + } > + > + /* See if it makes sense to encode it as "hex,hex,hex" for each 32-bit > + * chunk. We rely on the key having been padded out to a whole number > + * of 32-bit words. > + */ > + n = round_up(keylen, 4); > + nbe = nle = 0; > + for (i = 0; i < n; i += 4) { > + u32 be = be32_to_cpu(*(__be32 *)(key + i)); > + u32 le = le32_to_cpu(*(__le32 *)(key + i)); > + > + nbe += 1 + how_many_hex_digits(be); > + nle += 1 + how_many_hex_digits(le); > + } > + > + b64len = DIV_ROUND_UP(keylen, 3); > + pad = b64len * 3 - keylen; > + b64len = 2 + b64len * 4; /* Length if we base64-encode it */ > + _debug("len=%u nbe=%u nle=%u b64=%u", keylen, nbe, nle, b64len); > + if (nbe < b64len || nle < b64len) { > + unsigned int nlen = min(nbe, nle) + 1; > + name = kmalloc(nlen, GFP_KERNEL); > + if (!name) > + return false; > + sep = (nbe <= nle) ? 'S' : 'T'; /* Encoding indicator */ > + len = 0; > + for (i = 0; i < n; i += 4) { > + u32 x; > + if (nbe <= nle) > + x = be32_to_cpu(*(__be32 *)(key + i)); > + else > + x = le32_to_cpu(*(__le32 *)(key + i)); > + name[len++] = sep; > + if (x != 0) > + len += snprintf(name + len, nlen - len, "%x", x); > + sep = ','; > + } > + goto success; > + } > + > + /* We need to base64-encode it */ > + name = kmalloc(b64len + 1, GFP_KERNEL); > + if (!name) > + return false; > + > + name[0] = 'E'; > + name[1] = '0' + pad; > + len = 2; > + kend = key + keylen; > + do { > + acc = *key++; > + if (key < kend) { > + acc |= *key++ << 8; > + if (key < kend) > + acc |= *key++ << 16; > + } > + > + name[len++] = cachefiles_charmap[acc & 63]; > + acc >>= 6; > + name[len++] = cachefiles_charmap[acc & 63]; > + acc >>= 6; > + name[len++] = cachefiles_charmap[acc & 63]; > + acc >>= 6; > + name[len++] = cachefiles_charmap[acc & 63]; > + } while (key < kend); > + > +success: > + name[len] = 0; ^ then it seems that this will cause an out-of-boundary access. > + object->d_name = name; > + object->d_name_len = len; > + _leave(" = %s", object->d_name); > + return true; > +} > -- Thanks, Jeffle
next prev parent reply other threads:[~2021-12-01 5:46 UTC|newest] Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-11-29 14:22 [PATCH 00/64] fscache, cachefiles: Rewrite David Howells 2021-11-29 14:22 ` [PATCH 01/64] fscache, cachefiles: Disable configuration David Howells 2021-11-29 14:22 ` [PATCH 02/64] cachefiles: Delete the cachefiles driver pending rewrite David Howells 2021-11-29 14:23 ` [PATCH 03/64] fscache: Remove the contents of the fscache driver, " David Howells 2021-11-29 14:23 ` [PATCH 04/64] netfs: Display the netfs inode number in the netfs_read tracepoint David Howells 2021-11-29 14:23 ` [PATCH 05/64] netfs: Pass a flag to ->prepare_write() to say if there's no alloc'd space David Howells 2021-11-29 14:24 ` [PATCH 06/64] fscache: Introduce new driver David Howells 2021-11-29 14:24 ` [PATCH 07/64] fscache: Implement a hash function David Howells 2021-11-29 14:24 ` [PATCH 08/64] fscache: Implement cache registration David Howells 2021-11-29 14:24 ` [PATCH 09/64] fscache: Implement volume registration David Howells 2021-11-29 14:25 ` [PATCH 10/64] fscache: Implement cookie registration David Howells 2021-11-29 14:25 ` [PATCH 11/64] fscache: Implement cache-level access helpers David Howells 2021-11-29 14:25 ` [PATCH 12/64] fscache: Implement volume-level " David Howells 2021-11-29 14:25 ` [PATCH 13/64] fscache: Implement cookie-level " David Howells 2021-11-29 14:26 ` [PATCH 14/64] fscache: Implement functions add/remove a cache David Howells 2021-11-29 14:26 ` [PATCH 15/64] fscache: Provide and use cache methods to lookup/create/free a volume David Howells 2021-11-29 14:26 ` [PATCH 16/64] fscache: Add a function for a cache backend to note an I/O error David Howells 2021-11-29 14:26 ` [PATCH 17/64] fscache: Implement simple cookie state machine David Howells 2021-11-29 14:26 ` [PATCH 18/64] fscache: Implement cookie user counting and resource pinning David Howells 2021-11-29 14:27 ` [PATCH 19/64] fscache: Implement cookie invalidation David Howells 2021-11-29 14:27 ` [PATCH 20/64] fscache: Provide a means to begin an operation David Howells 2021-11-29 14:28 ` [PATCH 21/64] fscache: Count data storage objects in a cache David Howells 2021-11-29 14:28 ` [PATCH 22/64] fscache: Provide read/write stat counters for the cache David Howells 2021-11-29 14:28 ` [PATCH 23/64] fscache: Provide a function to let the netfs update its coherency data David Howells 2021-11-29 14:28 ` [PATCH 24/64] netfs: Pass more information on how to deal with a hole in the cache David Howells 2021-12-06 11:42 ` JeffleXu 2021-12-09 16:49 ` David Howells 2021-11-29 14:28 ` [PATCH 25/64] fscache: Implement raw I/O interface David Howells 2021-11-29 14:29 ` [PATCH 26/64] fscache: Implement higher-level write " David Howells 2021-11-29 14:29 ` [PATCH 27/64] vfs, fscache: Implement pinning of cache usage for writeback David Howells 2021-11-29 14:29 ` [PATCH 28/64] fscache: Provide a function to note the release of a page David Howells 2021-11-29 14:30 ` [PATCH 29/64] fscache: Provide a function to resize a cookie David Howells 2021-11-29 14:30 ` [PATCH 30/64] cachefiles: Introduce rewritten driver David Howells 2021-11-29 14:30 ` [PATCH 31/64] cachefiles: Define structs David Howells 2021-11-29 14:30 ` [PATCH 32/64] cachefiles: Add some error injection support David Howells 2021-11-29 14:30 ` [PATCH 33/64] cachefiles: Add a couple of tracepoints for logging errors David Howells 2021-11-29 14:31 ` [PATCH 34/64] cachefiles: Add cache error reporting macro David Howells 2021-11-29 14:31 ` [PATCH 35/64] cachefiles: Add security derivation David Howells 2021-11-29 14:31 ` [PATCH 36/64] cachefiles: Register a miscdev and parse commands over it David Howells 2021-11-29 14:31 ` [PATCH 37/64] cachefiles: Provide a function to check how much space there is David Howells 2021-11-29 14:31 ` [PATCH 38/64] vfs, cachefiles: Mark a backing file in use with an inode flag David Howells 2021-11-29 14:31 ` [PATCH 39/64] cachefiles: Implement a function to get/create a directory in the cache David Howells 2021-11-29 14:32 ` [PATCH 40/64] cachefiles: Implement cache registration and withdrawal David Howells 2021-11-29 14:32 ` [PATCH 41/64] cachefiles: Implement volume support David Howells 2021-11-29 14:33 ` [PATCH 42/64] cachefiles: Add tracepoints for calls to the VFS David Howells 2021-11-29 14:33 ` [PATCH 43/64] cachefiles: Implement object lifecycle funcs David Howells 2021-11-29 14:33 ` [PATCH 44/64] cachefiles: Implement key to filename encoding David Howells 2021-12-01 5:46 ` JeffleXu [this message] 2021-12-01 8:29 ` David Howells 2021-11-29 14:33 ` [PATCH 45/64] cachefiles: Implement metadata/coherency data storage in xattrs David Howells 2021-11-29 14:33 ` [PATCH 46/64] cachefiles: Mark a backing file in use with an inode flag David Howells 2021-11-29 14:33 ` [PATCH 47/64] cachefiles: Implement culling daemon commands David Howells 2021-11-29 14:34 ` [PATCH 48/64] cachefiles: Implement backing file wrangling David Howells 2021-11-29 14:34 ` [PATCH 49/64] cachefiles: Implement begin and end I/O operation David Howells 2021-11-29 14:34 ` [PATCH 50/64] cachefiles: Implement cookie resize for truncate David Howells 2021-11-29 14:34 ` [PATCH 51/64] cachefiles: Implement the I/O routines David Howells 2021-11-30 16:15 ` Nathan Chancellor 2021-11-30 21:05 ` David Howells 2021-11-29 14:34 ` [PATCH 52/64] cachefiles: Allow cachefiles to actually function David Howells 2021-11-29 14:35 ` [PATCH 53/64] fscache, cachefiles: Display stats of no-space events David Howells 2021-11-29 14:35 ` [PATCH 54/64] fscache, cachefiles: Display stat of culling events David Howells 2021-11-29 14:36 ` [PATCH 55/64] afs: Handle len being extending over page end in write_begin/write_end David Howells 2021-11-29 14:36 ` [PATCH 56/64] afs: Fix afs_write_end() to handle len > page size David Howells 2021-11-29 14:36 ` [PATCH 57/64] afs: Convert afs to use the new fscache API David Howells 2021-11-29 14:37 ` [PATCH 58/64] afs: Copy local writes to the cache when writing to the server David Howells 2021-11-29 14:37 ` [PATCH 59/64] afs: Skip truncation on the server of data we haven't written yet David Howells 2021-11-29 14:37 ` [PATCH 60/64] 9p: Use fscache indexing rewrite and reenable caching David Howells 2021-11-29 14:37 ` [PATCH 61/64] 9p: Copy local writes to the cache when writing to the server David Howells 2021-11-29 14:38 ` [PATCH 62/64] nfs: Convert to new fscache volume/cookie API David Howells 2021-11-29 14:38 ` [PATCH 63/64] cifs: Support fscache indexing rewrite (untested) David Howells 2021-11-29 14:38 ` [PATCH 64/64] fscache: Rewrite documentation David Howells 2021-11-29 18:12 ` [PATCH 00/64] fscache, cachefiles: Rewrite Linus Torvalds 2021-11-29 21:40 ` [PATCH 35/64] cachefiles: Add security derivation David Howells
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bcefb8f2-576a-b3fc-cc29-89808ebfd7c1@linux.alibaba.com \ --to=jefflexu@linux.alibaba.com \ --cc=anna.schumaker@netapp.com \ --cc=asmadeus@codewreck.org \ --cc=ceph-devel@vger.kernel.org \ --cc=dhowells@redhat.com \ --cc=jlayton@kernel.org \ --cc=linux-afs@lists.infradead.org \ --cc=linux-cachefs@redhat.com \ --cc=linux-cifs@vger.kernel.org \ --cc=linux-fsdevel@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-nfs@vger.kernel.org \ --cc=osandov@osandov.com \ --cc=sfrench@samba.org \ --cc=torvalds@linux-foundation.org \ --cc=trondmy@hammerspace.com \ --cc=v9fs-developer@lists.sourceforge.net \ --cc=viro@zeniv.linux.org.uk \ --cc=willy@infradead.org \ --subject='Re: [PATCH 44/64] cachefiles: Implement key to filename encoding' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.