linux-toradex.git/fs/f2fs, branch v4.9.34 Linux kernel for Apalis and Colibri modules crypto: Work around deallocated stack frame reference gcc bug on sparc. 2017-06-24T05:11:17+00:00 David Miller davem@davemloft.net 2017-06-02T15:28:54+00:00 b355b899c74a11c06e1edd4812d4c8809ec36c5e commit d41519a69b35b10af7fda867fb9100df24fdf403 upstream. On sparc, if we have an alloca() like situation, as is the case with SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack memory. The result can be that the value is clobbered if a trap or interrupt arrives at just the right instruction. It only occurs if the function ends returning a value from that alloca() area and that value can be placed into the return value register using a single instruction. For example, in lib/libcrc32c.c:crc32c() we end up with a return sequence like: return %i7+8 lduw [%o5+16], %o0 ! MEM[(u32 *)__shash_desc.1_10 + 16B], %o5 holds the base of the on-stack area allocated for the shash descriptor. But the return released the stack frame and the register window. So if an intererupt arrives between 'return' and 'lduw', then the value read at %o5+16 can be corrupted. Add a data compiler barrier to work around this problem. This is exactly what the gcc fix will end up doing as well, and it absolutely should not change the code generated for other cpus (unless gcc on them has the same bug :-) With crucial insight from Eric Sandeen. Reported-by: Anatoly Pugachev <matorola@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d41519a69b35b10af7fda867fb9100df24fdf403 upstream.

On sparc, if we have an alloca() like situation, as is the case with
SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack
memory.  The result can be that the value is clobbered if a trap
or interrupt arrives at just the right instruction.

It only occurs if the function ends returning a value from that
alloca() area and that value can be placed into the return value
register using a single instruction.

For example, in lib/libcrc32c.c:crc32c() we end up with a return
sequence like:

        return  %i7+8
         lduw   [%o5+16], %o0   ! MEM[(u32 *)__shash_desc.1_10 + 16B],

%o5 holds the base of the on-stack area allocated for the shash
descriptor.  But the return released the stack frame and the
register window.

So if an intererupt arrives between 'return' and 'lduw', then
the value read at %o5+16 can be corrupted.

Add a data compiler barrier to work around this problem.  This is
exactly what the gcc fix will end up doing as well, and it absolutely
should not change the code generated for other cpus (unless gcc
on them has the same bug :-)

With crucial insight from Eric Sandeen.

Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fscrypt: avoid collisions when presenting long encrypted filenames 2017-05-25T13:44:38+00:00 Eric Biggers ebiggers@google.com 2017-04-24T17:00:09+00:00 af9bd521885569799475fefcf3333a9ace5ce51f 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>
f2fs: check entire encrypted bigname when finding a dentry 2017-05-25T13:44:38+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-04-24T17:00:08+00:00 8daed21dbce1d28fd082ef6f2faf8990ccebfd6f 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 Cc: <stable@vger.kernel.org> 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

Cc: <stable@vger.kernel.org>
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: sanity check segment count 2017-05-14T12:00:22+00:00 Jin Qian jinqian@google.com 2017-04-25T23:28:48+00:00 93862955cbf485215f0677229292d0f358af55fc commit b9dd46188edc2f0d1f37328637860bb65a771124 upstream. F2FS uses 4 bytes to represent block address. As a result, supported size of disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments. Signed-off-by: Jin Qian <jinqian@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b9dd46188edc2f0d1f37328637860bb65a771124 upstream.

F2FS uses 4 bytes to represent block address. As a result, supported
size of disk is 16 TB and it equals to 16 * 1024 * 1024 / 2 segments.

Signed-off-by: Jin Qian <jinqian@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: avoid to issue redundant discard commands 2017-03-12T05:41:51+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-02-27T19:57:11+00:00 8c53efc399565ef4be8945c9bf45c94153699221 commit 8b107f5b97772c7c0c218302e9a4d15b4edf50b4 upstream. If segs_per_sec is over 1 like under SMR, previously f2fs issues discard commands redundantly on the same section, since we didn't move end position for the previous discard command. E.g., start end | | prefree_bitmap = [01111100111100] And, after issue discard for this section, end start | | prefree_bitmap = [01111100111100] Select this section again by searching from (end + 1), start end | | prefree_bitmap = [01111100111100] Fixes: 36abef4e796d38 ("f2fs: introduce mode=lfs mount option") Cc: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8b107f5b97772c7c0c218302e9a4d15b4edf50b4 upstream.

If segs_per_sec is over 1 like under SMR, previously f2fs issues discard
commands redundantly on the same section, since we didn't move end position
for the previous discard command.

E.g.,

                       start  end
                         |    |
      prefree_bitmap = [01111100111100]

And, after issue discard for this section,
                             end      start
                              |        |
      prefree_bitmap = [01111100111100]

Select this section again by searching from (end + 1),
                             start  end
                                |   |
      prefree_bitmap = [01111100111100]

Fixes: 36abef4e796d38 ("f2fs: introduce mode=lfs mount option")
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: add ovp valid_blocks check for bg gc victim to fg_gc 2017-03-12T05:41:51+00:00 Hou Pengyang houpengyang@huawei.com 2017-02-16T12:34:31+00:00 4992ba2840bd40a85887a1a0e5d69f688f58f9dd commit e93b9865251a0503d83fd570e7d5a7c8bc351715 upstream. For foreground gc, greedy algorithm should be adapted, which makes this formula work well: (2 * (100 / config.overprovision + 1) + 6) But currently, we fg_gc have a prior to select bg_gc victim segments to gc first, these victims are selected by cost-benefit algorithm, we can't guarantee such segments have the small valid blocks, which may destroy the f2fs rule, on the worstest case, would consume all the free segments. This patch fix this by add a filter in check_bg_victims, if segment's has # of valid blocks over overprovision ratio, skip such segments. Signed-off-by: Hou Pengyang <houpengyang@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 e93b9865251a0503d83fd570e7d5a7c8bc351715 upstream.

For foreground gc, greedy algorithm should be adapted, which makes
this formula work well:

	(2 * (100 / config.overprovision + 1) + 6)

But currently, we fg_gc have a prior to select bg_gc victim segments to gc
first, these victims are selected by cost-benefit algorithm, we can't guarantee
such segments have the small valid blocks, which may destroy the f2fs rule, on
the worstest case, would consume all the free segments.

This patch fix this by add a filter in check_bg_victims, if segment's has # of
valid blocks over overprovision ratio, skip such segments.

Signed-off-by: Hou Pengyang <houpengyang@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 multiple f2fs_add_link() calls having same name 2017-03-12T05:41:51+00:00 Jaegeuk Kim jaegeuk@kernel.org 2017-02-14T17:54:37+00:00 d00d1b71d98468ad6fbee590705c27fc1241f96e commit 88c5c13a5027b36d914536fdba23f069d7067204 upstream. It turns out a stakable filesystem like sdcardfs in AOSP can trigger multiple vfs_create() to lower filesystem. In that case, f2fs will add multiple dentries having same name which breaks filesystem consistency. Until upper layer fixes, let's work around by f2fs, which shows actually not much performance regression. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 88c5c13a5027b36d914536fdba23f069d7067204 upstream.

It turns out a stakable filesystem like sdcardfs in AOSP can trigger multiple
vfs_create() to lower filesystem. In that case, f2fs will add multiple dentries
having same name which breaks filesystem consistency.

Until upper layer fixes, let's work around by f2fs, which shows actually not
much performance regression.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: fix a problem of using memory after free 2017-03-12T05:41:51+00:00 Yunlei He heyunlei@huawei.com 2016-12-19T12:10:48+00:00 ec160ad2acaad4a7de6eab7338ef5e3b2b19f907 commit 7855eba4d6102f811b6dd142d6c749f53b591fa3 upstream. This patch fix a problem of using memory after free in function __try_merge_extent_node. Fixes: 0f825ee6e873 ("f2fs: add new interfaces for extent tree") Signed-off-by: Yunlei He <heyunlei@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 7855eba4d6102f811b6dd142d6c749f53b591fa3 upstream.

This patch fix a problem of using memory after free
in function __try_merge_extent_node.

Fixes: 0f825ee6e873 ("f2fs: add new interfaces for extent tree")
Signed-off-by: Yunlei He <heyunlei@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: hide a maybe-uninitialized warning 2017-01-12T10:39:35+00:00 Arnd Bergmann arnd@arndb.de 2016-11-02T13:52:15+00:00 a299abd230818ceb4e68520ba2f442194267cc50 commit 230436b3ef3fd7d4a1da19edf5e87bb2d74e0fc2 upstream. gcc is unsure about the use of last_ofs_in_node, which might happen without a prior initialization: fs/f2fs//git/arm-soc/fs/f2fs/data.c: In function ‘f2fs_map_blocks’: fs/f2fs/data.c:799:54: warning: ‘last_ofs_in_node’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) { As pointed out by Chao Yu, the code is actually correct as 'prealloc' is only set if the last_ofs_in_node has been set, the two always get updated together. This initializes last_ofs_in_node to dn.ofs_in_node for each new dnode at the start of the 'next_block' loop, which at that point is a correct initialization as well. I assume that compilers that correctly track the contents of the variables and do not warn about the condition also figure out that they can eliminate the extra assignment here. Fixes: 46008c6d4232 ("f2fs: support in batch multi blocks preallocation") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 230436b3ef3fd7d4a1da19edf5e87bb2d74e0fc2 upstream.

gcc is unsure about the use of last_ofs_in_node, which might happen
without a prior initialization:

fs/f2fs//git/arm-soc/fs/f2fs/data.c: In function ‘f2fs_map_blocks’:
fs/f2fs/data.c:799:54: warning: ‘last_ofs_in_node’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {

As pointed out by Chao Yu, the code is actually correct as 'prealloc'
is only set if the last_ofs_in_node has been set, the two always
get updated together.

This initializes last_ofs_in_node to dn.ofs_in_node for each
new dnode at the start of the 'next_block' loop, which at that
point is a correct initialization as well. I assume that compilers
that correctly track the contents of the variables and do not
warn about the condition also figure out that they can eliminate
the extra assignment here.

Fixes: 46008c6d4232 ("f2fs: support in batch multi blocks preallocation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: remove percpu_count due to performance regression 2017-01-12T10:39:35+00:00 Jaegeuk Kim jaegeuk@kernel.org 2016-10-21T02:09:57+00:00 725ba1a3ebc49478f76dea369563a79c86546fbd commit 35782b233f37e48ecc469d9c7232f3f6a7fad41a upstream. This patch removes percpu_count usage due to performance regression in iozone. Fixes: 523be8a6b3 ("f2fs: use percpu_counter for page counters") Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 35782b233f37e48ecc469d9c7232f3f6a7fad41a upstream.

This patch removes percpu_count usage due to performance regression in iozone.

Fixes: 523be8a6b3 ("f2fs: use percpu_counter for page counters")
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>