From: Zooko O'Whielacronx Date: Tue, 30 Dec 2008 07:52:26 +0000 (-0700) Subject: docs: split historical/historical_known_issues.txt out of known_issues.txt X-Git-Url: https://git.rkrishnan.org/pf/content/en/service/rgr-080307.php?a=commitdiff_plain;h=698dbfa78a7e5a8b2d9d750ee5ce08e2b84a86b8;p=tahoe-lafs%2Ftahoe-lafs.git docs: split historical/historical_known_issues.txt out of known_issues.txt All issues which are relevant to users of v1.1, v1.2, or v1.3 go in known_issues.txt. All issues which are relevant to users of v1.0 go in historical/historical_known_issues.txt. --- diff --git a/docs/historical/historical_known_issues.txt b/docs/historical/historical_known_issues.txt new file mode 100644 index 00000000..88d76c06 --- /dev/null +++ b/docs/historical/historical_known_issues.txt @@ -0,0 +1,136 @@ += Known Issues = + +Below is a list of known issues in older releases of Tahoe-LAFS, and how to +manage them. The current version of this file can be found at + +http://allmydata.org/source/tahoe/trunk/docs/historical/historical_known_issues.txt + +Newer versions of this document describing issues in newer releases of +Tahoe-LAFS can be found at: + +http://allmydata.org/source/tahoe/trunk/docs/known_issues.txt + +== issues in Tahoe v1.0.0, released 2008-03-25 == + +(Tahoe v1.0 was superceded by v1.1 which was released 2008-06-11.) + +=== issue 6: server out of space when writing mutable file === + +In addition to the problems caused by insufficient disk space +described above, v1.0 clients which are writing mutable files when the +servers fail to write to their filesystem are likely to think the +write succeeded, when it in fact failed. This can cause data loss. + +==== how to manage it ==== + +Upgrade client to v1.1, or make sure that servers are always able to +write to their local filesystem (including that there is space +available) as described in "issue 1" above. + + +=== issue 5: server out of space when writing immutable file === + +Tahoe v1.0 clients are using v1.0 servers which are unable to write to +their filesystem during an immutable upload will correctly detect the +first failure, but if they retry the upload without restarting the +client, or if another client attempts to upload the same file, the +second upload may appear to succeed when it hasn't, which can lead to +data loss. + +==== how to manage it ==== + +Upgrading either or both of the client and the server to v1.1 will fix +this issue. Also it can be avoided by ensuring that the servers are +always able to write to their local filesystem (including that there +is space available) as described in "issue 1" above. + + +=== issue 4: large directories or mutable files of certain sizes === + +If a client attempts to upload a large mutable file with a size +greater than about 3,139,000 and less than or equal to 3,500,000 bytes +then it will fail but appear to succeed, which can lead to data loss. + +(Mutable files larger than 3,500,000 are refused outright). The +symptom of the failure is very high memory usage (3 GB of memory) and +100% CPU for about 5 minutes, before it appears to succeed, although +it hasn't. + +Directories are stored in mutable files, and a directory of +approximately 9000 entries may fall into this range of mutable file +sizes (depending on the size of the filenames or other metadata +associated with the entries). + +==== how to manage it ==== + +This was fixed in v1.1, under ticket #379. If the client is upgraded +to v1.1, then it will fail cleanly instead of falsely appearing to +succeed when it tries to write a file whose size is in this range. If +the server is also upgraded to v1.1, then writes of mutable files +whose size is in this range will succeed. (If the server is upgraded +to v1.1 but the client is still v1.0 then the client will still suffer +this failure.) + + +=== issue 3: uploading files greater than 12 GiB === + +If a Tahoe v1.0 client uploads a file greater than 12 GiB in size, the file will +be silently corrupted so that it is not retrievable, but the client will think +that it succeeded. This is a "data loss" failure. + +==== how to manage it ==== + +Don't upload files larger than 12 GiB. If you have previously uploaded files of +that size, assume that they have been corrupted and are not retrievable from the +Tahoe storage grid. Tahoe v1.1 clients will refuse to upload files larger than +12 GiB with a clean failure. A future release of Tahoe will remove this +limitation so that larger files can be uploaded. + + +=== issue 2: pycryptopp defect resulting in data corruption === + +Versions of pycryptopp earlier than pycryptopp-0.5.0 had a defect +which, when compiled with some compilers, would cause AES-256 +encryption and decryption to be computed incorrectly. This could +cause data corruption. Tahoe v1.0 required, and came with a bundled +copy of, pycryptopp v0.3. + +==== how to manage it ==== + +You can detect whether pycryptopp-0.3 has this failure when it is +compiled by your compiler. Run the unit tests that come with +pycryptopp-0.3: unpack the "pycryptopp-0.3.tar" file that comes in the +Tahoe v1.0 {{{misc/dependencies}}} directory, cd into the resulting +{{{pycryptopp-0.3.0}}} directory, and execute {{{python ./setup.py +test}}}. If the tests pass, then your compiler does not trigger this +failure. + + +=== issue 1: potential disclosure of a file through embedded +hyperlinks or JavaScript in that file === + +If there is a file stored on a Tahoe storage grid, and that file gets +downloaded and displayed in a web browser, then JavaScript or +hyperlinks within that file can leak the capability to that file to a +third party, which means that third party gets access to the file. + +If there is JavaScript in the file, then it could deliberately leak +the capability to the file out to some remote listener. + +If there are hyperlinks in the file, and they get followed, then +whichever server they point to receives the capability to the +file. Note that IMG tags are typically followed automatically by web +browsers, so being careful which hyperlinks you click on is not +sufficient to prevent this from happening. + +==== how to manage it ==== + +For future versions of Tahoe, we are considering ways to close off +this leakage of authority while preserving ease of use -- the +discussion of this issue is ticket #127. + +For the present, a good work-around is that if you want to store and +view a file on Tahoe and you want that file to remain private, then +remove from that file any hyperlinks pointing to other people's +servers and remove any JavaScript unless you are sure that the +JavaScript is not written to maliciously leak access. diff --git a/docs/known_issues.txt b/docs/known_issues.txt index 1382c66f..6afd264b 100644 --- a/docs/known_issues.txt +++ b/docs/known_issues.txt @@ -1,11 +1,14 @@ = Known Issues = -Below is a list of known issues in recent releases of allmydata.org -Tahoe, the Least-Authority Filesystem, and how to manage them. The -current version of this file can be found at +Below is a list of known issues in recent releases of Tahoe-LAFS, and how to +manage them. The current version of this file can be found at http://allmydata.org/source/tahoe/trunk/docs/known_issues.txt +Older versions of this document describing issues in older versions of +Tahoe-LAFS can be found at + +http://allmydata.org/source/tahoe/trunk/docs/historical/historical_known_issues.txt == issues in Tahoe v1.2.0, released 2008-06-21 == @@ -29,7 +32,8 @@ bypassed, and other users will not be able to see them. Once you've added the alias, no other secrets are passed through the command line, so this vulnerability becomes less significant: they can still see your filenames and other arguments you type there, but not the caps that Tahoe uses to permit -access to your files and directories. +access to your files and directories. In Tahoe v1.3.0, there is a new +"tahoe create-aliase" command that does this for you. == issues in Tahoe v1.1.0, released 2008-06-11 == @@ -129,104 +133,9 @@ being tested is correct. If you are using Twisted v8 and pyOpenSSL v0.7, then please ignore ERROR "Reactor was unclean" in test_system and test_introducer. -Downgrading to an older version of Twisted or pyOpenSSL will cause -those false alarms to stop happening. - - -== issues in Tahoe v1.0.0, released 2008-03-25 == - -(Tahoe v1.0 was superceded by v1.1 which was released 2008-06-11.) - -=== issue 6: server out of space when writing mutable file === - -In addition to the problems caused by insufficient disk space -described above, v1.0 clients which are writing mutable files when the -servers fail to write to their filesystem are likely to think the -write succeeded, when it in fact failed. This can cause data loss. - -==== how to manage it ==== - -Upgrade client to v1.1, or make sure that servers are always able to -write to their local filesystem (including that there is space -available) as described in "issue 1" above. - - -=== issue 5: server out of space when writing immutable file === - -Tahoe v1.0 clients are using v1.0 servers which are unable to write to -their filesystem during an immutable upload will correctly detect the -first failure, but if they retry the upload without restarting the -client, or if another client attempts to upload the same file, the -second upload may appear to succeed when it hasn't, which can lead to -data loss. - -==== how to manage it ==== - -Upgrading either or both of the client and the server to v1.1 will fix -this issue. Also it can be avoided by ensuring that the servers are -always able to write to their local filesystem (including that there -is space available) as described in "issue 1" above. - - -=== issue 4: large directories or mutable files of certain sizes === - -If a client attempts to upload a large mutable file with a size -greater than about 3,139,000 and less than or equal to 3,500,000 bytes -then it will fail but appear to succeed, which can lead to data loss. - -(Mutable files larger than 3,500,000 are refused outright). The -symptom of the failure is very high memory usage (3 GB of memory) and -100% CPU for about 5 minutes, before it appears to succeed, although -it hasn't. - -Directories are stored in mutable files, and a directory of -approximately 9000 entries may fall into this range of mutable file -sizes (depending on the size of the filenames or other metadata -associated with the entries). - -==== how to manage it ==== - -This was fixed in v1.1, under ticket #379. If the client is upgraded -to v1.1, then it will fail cleanly instead of falsely appearing to -succeed when it tries to write a file whose size is in this range. If -the server is also upgraded to v1.1, then writes of mutable files -whose size is in this range will succeed. (If the server is upgraded -to v1.1 but the client is still v1.0 then the client will still suffer -this failure.) - - -=== issue 3: uploading files greater than 12 GiB === - -If a Tahoe v1.0 client uploads a file greater than 12 GiB in size, the file will -be silently corrupted so that it is not retrievable, but the client will think -that it succeeded. This is a "data loss" failure. - -==== how to manage it ==== - -Don't upload files larger than 12 GiB. If you have previously uploaded files of -that size, assume that they have been corrupted and are not retrievable from the -Tahoe storage grid. Tahoe v1.1 clients will refuse to upload files larger than -12 GiB with a clean failure. A future release of Tahoe will remove this -limitation so that larger files can be uploaded. - - -=== issue 2: pycryptopp defect resulting in data corruption === - -Versions of pycryptopp earlier than pycryptopp-0.5.0 had a defect -which, when compiled with some compilers, would cause AES-256 -encryption and decryption to be computed incorrectly. This could -cause data corruption. Tahoe v1.0 required, and came with a bundled -copy of, pycryptopp v0.3. - -==== how to manage it ==== - -You can detect whether pycryptopp-0.3 has this failure when it is -compiled by your compiler. Run the unit tests that come with -pycryptopp-0.3: unpack the "pycryptopp-0.3.tar" file that comes in the -Tahoe v1.0 {{{misc/dependencies}}} directory, cd into the resulting -{{{pycryptopp-0.3.0}}} directory, and execute {{{python ./setup.py -test}}}. If the tests pass, then your compiler does not trigger this -failure. +Upgrading to a newer version of Twisted or pyOpenSSL will cause those +false alarms to stop happening (as will downgrading to an older +version of either of those packages). === issue 1: potential disclosure of a file through embedded