linux-stable.git/fs, branch v4.11.2 Linux kernel stable tree pstore: Shut down worker when unregistering 2017-05-20T12:49:51+00:00 Kees Cook keescook@chromium.org 2017-03-06T20:42:12+00:00 bbc105f3878b9e69479bfc0a758b4fec64c71cd0 commit 6330d5534786d5315d56d558aa6d20740f97d80a upstream. When built as a module and running with update_ms >= 0, pstore will Oops during module unload since the work timer is still running. This makes sure the worker is stopped before unloading. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6330d5534786d5315d56d558aa6d20740f97d80a upstream.

When built as a module and running with update_ms >= 0, pstore will Oops
during module unload since the work timer is still running. This makes sure
the worker is stopped before unloading.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pstore: Use dynamic spinlock initializer 2017-05-20T12:49:51+00:00 Kees Cook keescook@chromium.org 2017-03-06T06:08:58+00:00 ed8834ea4f43cf7854de62f8985b01c088ba8a75 commit e9a330c4289f2ba1ca4bf98c2b430ab165a8931b upstream. The per-prz spinlock should be using the dynamic initializer so that lockdep can correctly track it. Without this, under lockdep, we get a warning at boot that the lock is in non-static memory. Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Fixes: 76d5692a5803 ("pstore: Correctly initialize spinlock and flags") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e9a330c4289f2ba1ca4bf98c2b430ab165a8931b upstream.

The per-prz spinlock should be using the dynamic initializer so that
lockdep can correctly track it. Without this, under lockdep, we get a
warning at boot that the lock is in non-static memory.

Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global")
Fixes: 76d5692a5803 ("pstore: Correctly initialize spinlock and flags")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fscrypt: avoid collisions when presenting long encrypted filenames 2017-05-20T12:49:49+00:00 Eric Biggers ebiggers@google.com 2017-04-24T17:00:09+00:00 ab62f4118ba1d010a994d79f55ea8bd0b48f5b98 commit 6b06cdee81d68a8a829ad8e8d0f31d6836744af9 upstream. When accessing an encrypted directory without the key, userspace must operate on filenames derived from the ciphertext names, which contain arbitrary bytes. Since we must support filenames as long as NAME_MAX, we can't always just base64-encode the ciphertext, since that may make it too long. Currently, this is solved by presenting long names in an abbreviated form containing any needed filesystem-specific hashes (e.g. to identify a directory block), then the last 16 bytes of ciphertext. This needs to be sufficient to identify the actual name on lookup. However, there is a bug. It seems to have been assumed that due to the use of a CBC (ciphertext block chaining)-based encryption mode, the last 16 bytes (i.e. the AES block size) of ciphertext would depend on the full plaintext, preventing collisions. However, we actually use CBC with ciphertext stealing (CTS), which handles the last two blocks specially, causing them to appear "flipped". Thus, it's actually the second-to-last block which depends on the full plaintext. This caused long filenames that differ only near the end of their plaintexts to, when observed without the key, point to the wrong inode and be undeletable. For example, with ext4: # echo pass | e4crypt add_key -p 16 edir/ # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch # find edir/ -type f | xargs stat -c %i | sort | uniq | wc -l 100000 # sync # echo 3 > /proc/sys/vm/drop_caches # keyctl new_session # find edir/ -type f | xargs stat -c %i | sort | uniq | wc -l 2004 # rm -rf edir/ rm: cannot remove 'edir/_A7nNFi3rhkEQlJ6P,hdzluhODKOeWx5V': Structure needs cleaning ... To fix this, when presenting long encrypted filenames, encode the second-to-last block of ciphertext rather than the last 16 bytes. Although it would be nice to solve this without depending on a specific encryption mode, that would mean doing a cryptographic hash like SHA-256 which would be much less efficient. This way is sufficient for now, and it's still compatible with encryption modes like HEH which are strong pseudorandom permutations. Also, changing the presented names is still allowed at any time because they are only provided to allow applications to do things like delete encrypted directories. They're not designed to be used to persistently identify files --- which would be hard to do anyway, given that they're encrypted after all. For ease of backports, this patch only makes the minimal fix to both ext4 and f2fs. It leaves ubifs as-is, since ubifs doesn't compare the ciphertext block yet. Follow-on patches will clean things up properly and make the filesystems use a shared helper function. Fixes: 5de0b4d0cd15 ("ext4 crypto: simplify and speed up filename encryption") Reported-by: Gwendal Grignou <gwendal@chromium.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6b06cdee81d68a8a829ad8e8d0f31d6836744af9 upstream.

When accessing an encrypted directory without the key, userspace must
operate on filenames derived from the ciphertext names, which contain
arbitrary bytes.  Since we must support filenames as long as NAME_MAX,
we can't always just base64-encode the ciphertext, since that may make
it too long.  Currently, this is solved by presenting long names in an
abbreviated form containing any needed filesystem-specific hashes (e.g.
to identify a directory block), then the last 16 bytes of ciphertext.
This needs to be sufficient to identify the actual name on lookup.

However, there is a bug.  It seems to have been assumed that due to the
use of a CBC (ciphertext block chaining)-based encryption mode, the last
16 bytes (i.e. the AES block size) of ciphertext would depend on the
full plaintext, preventing collisions.  However, we actually use CBC
with ciphertext stealing (CTS), which handles the last two blocks
specially, causing them to appear "flipped".  Thus, it's actually the
second-to-last block which depends on the full plaintext.

This caused long filenames that differ only near the end of their
plaintexts to, when observed without the key, point to the wrong inode
and be undeletable.  For example, with ext4:

    # echo pass | e4crypt add_key -p 16 edir/
    # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch
    # find edir/ -type f | xargs stat -c %i | sort | uniq | wc -l
    100000
    # sync
    # echo 3 > /proc/sys/vm/drop_caches
    # keyctl new_session
    # find edir/ -type f | xargs stat -c %i | sort | uniq | wc -l
    2004
    # rm -rf edir/
    rm: cannot remove 'edir/_A7nNFi3rhkEQlJ6P,hdzluhODKOeWx5V': Structure needs cleaning
    ...

To fix this, when presenting long encrypted filenames, encode the
second-to-last block of ciphertext rather than the last 16 bytes.

Although it would be nice to solve this without depending on a specific
encryption mode, that would mean doing a cryptographic hash like SHA-256
which would be much less efficient.  This way is sufficient for now, and
it's still compatible with encryption modes like HEH which are strong
pseudorandom permutations.  Also, changing the presented names is still
allowed at any time because they are only provided to allow applications
to do things like delete encrypted directories.  They're not designed to
be used to persistently identify files --- which would be hard to do
anyway, given that they're encrypted after all.

For ease of backports, this patch only makes the minimal fix to both
ext4 and f2fs.  It leaves ubifs as-is, since ubifs doesn't compare the
ciphertext block yet.  Follow-on patches will clean things up properly
and make the filesystems use a shared helper function.

Fixes: 5de0b4d0cd15 ("ext4 crypto: simplify and speed up filename encryption")
Reported-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fscrypt: fix context consistency check when key(s) unavailable 2017-05-20T12:49:49+00:00 Eric Biggers ebiggers@google.com 2017-04-07T17:58:37+00:00 eb86b4c68b8c59eec5e44fa7e1ea98c0a63eaa24 commit 272f98f6846277378e1758a49a49d7bf39343c02 upstream. To mitigate some types of offline attacks, filesystem encryption is designed to enforce that all files in an encrypted directory tree use the same encryption policy (i.e. the same encryption context excluding the nonce). However, the fscrypt_has_permitted_context() function which enforces this relies on comparing struct fscrypt_info's, which are only available when we have the encryption keys. This can cause two incorrect behaviors: 1. If we have the parent directory's key but not the child's key, or vice versa, then fscrypt_has_permitted_context() returned false, causing applications to see EPERM or ENOKEY. This is incorrect if the encryption contexts are in fact consistent. Although we'd normally have either both keys or neither key in that case since the master_key_descriptors would be the same, this is not guaranteed because keys can be added or removed from keyrings at any time. 2. If we have neither the parent's key nor the child's key, then fscrypt_has_permitted_context() returned true, causing applications to see no error (or else an error for some other reason). This is incorrect if the encryption contexts are in fact inconsistent, since in that case we should deny access. To fix this, retrieve and compare the fscrypt_contexts if we are unable to set up both fscrypt_infos. While this slightly hurts performance when accessing an encrypted directory tree without the key, this isn't a case we really need to be optimizing for; access *with* the key is much more important. Furthermore, the performance hit is barely noticeable given that we are already retrieving the fscrypt_context and doing two keyring searches in fscrypt_get_encryption_info(). If we ever actually wanted to optimize this case we might start by caching the fscrypt_contexts. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 272f98f6846277378e1758a49a49d7bf39343c02 upstream.

To mitigate some types of offline attacks, filesystem encryption is
designed to enforce that all files in an encrypted directory tree use
the same encryption policy (i.e. the same encryption context excluding
the nonce).  However, the fscrypt_has_permitted_context() function which
enforces this relies on comparing struct fscrypt_info's, which are only
available when we have the encryption keys.  This can cause two
incorrect behaviors:

1. If we have the parent directory's key but not the child's key, or
   vice versa, then fscrypt_has_permitted_context() returned false,
   causing applications to see EPERM or ENOKEY.  This is incorrect if
   the encryption contexts are in fact consistent.  Although we'd
   normally have either both keys or neither key in that case since the
   master_key_descriptors would be the same, this is not guaranteed
   because keys can be added or removed from keyrings at any time.

2. If we have neither the parent's key nor the child's key, then
   fscrypt_has_permitted_context() returned true, causing applications
   to see no error (or else an error for some other reason).  This is
   incorrect if the encryption contexts are in fact inconsistent, since
   in that case we should deny access.

To fix this, retrieve and compare the fscrypt_contexts if we are unable
to set up both fscrypt_infos.

While this slightly hurts performance when accessing an encrypted
directory tree without the key, this isn't a case we really need to be
optimizing for; access *with* the key is much more important.
Furthermore, the performance hit is barely noticeable given that we are
already retrieving the fscrypt_context and doing two keyring searches in
fscrypt_get_encryption_info().  If we ever actually wanted to optimize
this case we might start by caching the fscrypt_contexts.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: Make flush bios explicitely sync 2017-05-20T12:49:49+00:00 Jan Kara jack@suse.cz 2017-05-02T15:03:47+00:00 9b3be66cb479de75baafbf8ae2d3fcf979c109c2 commit 3adc5fcb7edf5f8dfe8d37dcb50ba6b30077c905 upstream. Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...} definitions. generic_make_request_checks() however strips REQ_FUA and REQ_PREFLUSH flags from a bio when the storage doesn't report volatile write cache and thus write effectively becomes asynchronous which can lead to performance regressions. Fix the problem by making sure all bios which are synchronous are properly marked with REQ_SYNC. Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3 CC: Jaegeuk Kim <jaegeuk@kernel.org> CC: linux-f2fs-devel@lists.sourceforge.net Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3adc5fcb7edf5f8dfe8d37dcb50ba6b30077c905 upstream.

Commit b685d3d65ac7 "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions.

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

Fixes: b685d3d65ac791406e0dfd8779cc9b3707fea5a3
CC: Jaegeuk Kim <jaegeuk@kernel.org>
CC: linux-f2fs-devel@lists.sourceforge.net
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: check entire encrypted bigname when finding a dentry 2017-05-20T12:49:49+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-04-24T17:00:08+00:00 bd3dfe5049498ee72c54341a12c5e84a6d61796a commit 6332cd32c8290a80e929fc044dc5bdba77396e33 upstream. If user has no key under an encrypted dir, fscrypt gives digested dentries. Previously, when looking up a dentry, f2fs only checks its hash value with first 4 bytes of the digested dentry, which didn't handle hash collisions fully. This patch enhances to check entire dentry bytes likewise ext4. Eric reported how to reproduce this issue by: # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch # find edir -type f | xargs stat -c %i | sort | uniq | wc -l 100000 # sync # echo 3 > /proc/sys/vm/drop_caches # keyctl new_session # find edir -type f | xargs stat -c %i | sort | uniq | wc -l 99999 Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> (fixed f2fs_dentry_hash() to work even when the hash is 0) Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6332cd32c8290a80e929fc044dc5bdba77396e33 upstream.

If user has no key under an encrypted dir, fscrypt gives digested dentries.
Previously, when looking up a dentry, f2fs only checks its hash value with
first 4 bytes of the digested dentry, which didn't handle hash collisions fully.
This patch enhances to check entire dentry bytes likewise ext4.

Eric reported how to reproduce this issue by:

 # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch
 # find edir -type f | xargs stat -c %i | sort | uniq | wc -l
100000
 # sync
 # echo 3 > /proc/sys/vm/drop_caches
 # keyctl new_session
 # find edir -type f | xargs stat -c %i | sort | uniq | wc -l
99999

Reported-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(fixed f2fs_dentry_hash() to work even when the hash is 0)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: fix multiple f2fs_add_link() having same name for inline dentry 2017-05-20T12:49:49+00:00 Sheng Yong shengyong1@huawei.com 2017-04-22T02:39:20+00:00 3a625468bd9e6a53d1078ba0a2e9c17117147183 commit d3bb910c15d75ee3340311c64a1c05985bb663a3 upstream. Commit 88c5c13a5027 (f2fs: fix multiple f2fs_add_link() calls having same name) does not cover the scenario where inline dentry is enabled. In that case, F2FS_I(dir)->task will be NULL, and __f2fs_add_link will lookup dentries one more time. This patch fixes it by moving the assigment of current task to a upper level to cover both normal and inline dentry. Fixes: 88c5c13a5027 (f2fs: fix multiple f2fs_add_link() calls having same name) Signed-off-by: Sheng Yong <shengyong1@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d3bb910c15d75ee3340311c64a1c05985bb663a3 upstream.

Commit 88c5c13a5027 (f2fs: fix multiple f2fs_add_link() calls having
same name) does not cover the scenario where inline dentry is enabled.
In that case, F2FS_I(dir)->task will be NULL, and __f2fs_add_link will
lookup dentries one more time.

This patch fixes it by moving the assigment of current task to a upper
level to cover both normal and inline dentry.

Fixes: 88c5c13a5027 (f2fs: fix multiple f2fs_add_link() calls having same name)
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: fix fs corruption due to zero inode page 2017-05-20T12:49:49+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-04-12T02:01:26+00:00 e71f099677c18c7c7d9363dc9e89d27fe4a33b06 commit 9bb02c3627f46e50246bf7ab957b56ffbef623cb upstream. This patch fixes the following scenario. - f2fs_create/f2fs_mkdir - write_checkpoint - f2fs_mark_inode_dirty_sync - block_operations - f2fs_lock_all - f2fs_sync_inode_meta - f2fs_unlock_all - sync_inode_metadata - f2fs_lock_op - f2fs_write_inode - update_inode_page - get_node_page return -ENOENT - new_inode_page - fill_node_footer - f2fs_mark_inode_dirty_sync - ... - f2fs_unlock_op - f2fs_inode_synced - f2fs_lock_all - do_checkpoint In this checkpoint, we can get an inode page which contains zeros having valid node footer only. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9bb02c3627f46e50246bf7ab957b56ffbef623cb upstream.

This patch fixes the following scenario.

- f2fs_create/f2fs_mkdir             - write_checkpoint
 - f2fs_mark_inode_dirty_sync         - block_operations
                                       - f2fs_lock_all
                                       - f2fs_sync_inode_meta
                                        - f2fs_unlock_all
                                        - sync_inode_metadata
 - f2fs_lock_op
                                         - f2fs_write_inode
                                          - update_inode_page
                                           - get_node_page
                                             return -ENOENT
 - new_inode_page
  - fill_node_footer
 - f2fs_mark_inode_dirty_sync
 - ...
 - f2fs_unlock_op
                                          - f2fs_inode_synced
                                       - f2fs_lock_all
                                       - do_checkpoint

In this checkpoint, we can get an inode page which contains zeros having valid
node footer only.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "f2fs: put allocate_segment after refresh_sit_entry" 2017-05-20T12:49:48+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-04-04T23:45:30+00:00 ed4d26a1e45b1cd0d2290cb50e9ab38ef74e0579 commit c6f82fe90d7458e5fa190a6820bfc24f96b0de4e upstream. This reverts commit 3436c4bdb30de421d46f58c9174669fbcfd40ce0. This makes a leak to register dirty segments. I reproduced the issue by modified postmark which injects a lot of file create/delete/update and finally triggers huge number of SSR allocations. [Jaegeuk Kim: Change missing incorrect comment] Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c6f82fe90d7458e5fa190a6820bfc24f96b0de4e upstream.

This reverts commit 3436c4bdb30de421d46f58c9174669fbcfd40ce0.

This makes a leak to register dirty segments. I reproduced the issue by
modified postmark which injects a lot of file create/delete/update and
finally triggers huge number of SSR allocations.

[Jaegeuk Kim: Change missing incorrect comment]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: fix wrong max cost initialization 2017-05-20T12:49:48+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-03-25T07:03:02+00:00 33cbcc2556b36a94b7387a995756e7c5f07e05d9 commit c541a51b8ce81d003b02ed67ad3604a2e6220e3e upstream. This patch fixes missing increased max cost caused by a patch that we increased cose of data segments in greedy algorithm. Fixes: b9cd20619 "f2fs: node segment is prior to data segment selected victim" Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c541a51b8ce81d003b02ed67ad3604a2e6220e3e upstream.

This patch fixes missing increased max cost caused by a patch that we increased
cose of data segments in greedy algorithm.

Fixes: b9cd20619 "f2fs: node segment is prior to data segment selected victim"
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>