linux-stable.git/fs/squashfs, branch v4.4.263

squashfs: add more sanity checks in xattr id lookup

2021-02-23T12:58:13+00:00

commit 506220d2ba21791314af569211ffd8870b8208fa upstream.

Sysbot has reported a warning where a kmalloc() attempt exceeds the
maximum limit.  This has been identified as corruption of the xattr_ids
count when reading the xattr id lookup table.

This patch adds a number of additional sanity checks to detect this
corruption and others.

1. It checks for a corrupted xattr index read from the inode.  This could
   be because the metadata block is uncompressed, or because the
   "compression" bit has been corrupted (turning a compressed block
   into an uncompressed block).  This would cause an out of bounds read.

2. It checks against corruption of the xattr_ids count.  This can either
   lead to the above kmalloc failure, or a smaller than expected
   table to be read.

3. It checks the contents of the index table for corruption.

[phillip@squashfs.org.uk: fix checkpatch issue]
  Link: https://lkml.kernel.org/r/270245655.754655.1612770082682@webmail.123-reg.co.uk

Link: https://lkml.kernel.org/r/20210204130249.4495-5-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher 
Reported-by: syzbot+2ccea6339d368360800d@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

squashfs: add more sanity checks in inode lookup

2021-02-23T12:58:12+00:00

commit eabac19e40c095543def79cb6ffeb3a8588aaff4 upstream.

Sysbot has reported an "slab-out-of-bounds read" error which has been
identified as being caused by a corrupted "ino_num" value read from the
inode.  This could be because the metadata block is uncompressed, or
because the "compression" bit has been corrupted (turning a compressed
block into an uncompressed block).

This patch adds additional sanity checks to detect this, and the
following corruption.

1. It checks against corruption of the inodes count.  This can either
   lead to a larger table to be read, or a smaller than expected
   table to be read.

   In the case of a too large inodes count, this would often have been
   trapped by the existing sanity checks, but this patch introduces
   a more exact check, which can identify too small values.

2. It checks the contents of the index table for corruption.

[phillip@squashfs.org.uk: fix checkpatch issue]
  Link: https://lkml.kernel.org/r/527909353.754618.1612769948607@webmail.123-reg.co.uk

Link: https://lkml.kernel.org/r/20210204130249.4495-4-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher 
Reported-by: syzbot+04419e3ff19d2970ea28@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

squashfs: add more sanity checks in id lookup

2021-02-23T12:58:12+00:00

commit f37aa4c7366e23f91b81d00bafd6a7ab54e4a381 upstream.

Sysbot has reported a number of "slab-out-of-bounds reads" and
"use-after-free read" errors which has been identified as being caused
by a corrupted index value read from the inode.  This could be because
the metadata block is uncompressed, or because the "compression" bit has
been corrupted (turning a compressed block into an uncompressed block).

This patch adds additional sanity checks to detect this, and the
following corruption.

1. It checks against corruption of the ids count.  This can either
   lead to a larger table to be read, or a smaller than expected
   table to be read.

   In the case of a too large ids count, this would often have been
   trapped by the existing sanity checks, but this patch introduces
   a more exact check, which can identify too small values.

2. It checks the contents of the index table for corruption.

Link: https://lkml.kernel.org/r/20210204130249.4495-3-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher 
Reported-by: syzbot+b06d57ba83f604522af2@syzkaller.appspotmail.com
Reported-by: syzbot+c021ba012da41ee9807c@syzkaller.appspotmail.com
Reported-by: syzbot+5024636e8b5fd19f0f19@syzkaller.appspotmail.com
Reported-by: syzbot+bcbc661df46657d0fa4f@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

squashfs: more metadata hardenings

2018-08-06T14:24:42+00:00

commit 71755ee5350b63fb1f283de8561cdb61b47f4d1d upstream.

The squashfs fragment reading code doesn't actually verify that the
fragment is inside the fragment table.  The end result _is_ verified to
be inside the image when actually reading the fragment data, but before
that is done, we may end up taking a page fault because the fragment
table itself might not even exist.

Another report from Anatoly and his endless squashfs image fuzzing.

Reported-by: Анатолий Тросиненко 
Acked-by:: Phillip Lougher ,
Cc: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

squashfs: more metadata hardening

2018-08-06T14:24:42+00:00

commit d512584780d3e6a7cacb2f482834849453d444a1 upstream.

Anatoly reports another squashfs fuzzing issue, where the decompression
parameters themselves are in a compressed block.

This causes squashfs_read_data() to be called in order to read the
decompression options before the decompression stream having been set
up, making squashfs go sideways.

Reported-by: Anatoly Trosinenko 
Acked-by: Phillip Lougher 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

squashfs: be more careful about metadata corruption

2018-08-06T14:24:40+00:00

commit 01cfb7937a9af2abb1136c7e89fbf3fd92952956 upstream.

Anatoly Trosinenko reports that a corrupted squashfs image can cause a
kernel oops.  It turns out that squashfs can end up being confused about
negative fragment lengths.

The regular squashfs_read_data() does check for negative lengths, but
squashfs_read_metadata() did not, and the fragment size code just
blindly trusted the on-disk value.  Fix both the fragment parsing and
the metadata reading code.

Reported-by: Anatoly Trosinenko 
Cc: Al Viro 
Cc: Phillip Lougher 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

squashfs: xattr simplifications

2015-11-14T01:34:33+00:00

Now that the xattr handler is passed to the xattr handler operations, we
have access to the attribute name prefix, so simplify the squashfs xattr
handlers a bit.

Signed-off-by: Andreas Gruenbacher 
Cc: Phillip Lougher 
Signed-off-by: Al Viro

xattr handlers: Pass handler to operations instead of flags

2015-11-14T01:34:32+00:00

The xattr_handler operations are currently all passed a file system
specific flags value which the operations can use to disambiguate between
different handlers; some file systems use that to distinguish the xattr
namespace, for example.  In some oprations, it would be useful to also have
access to the handler prefix.  To allow that, pass a pointer to the handler
to operations instead of the flags value alone.

Signed-off-by: Andreas Gruenbacher 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Al Viro

fs: cleanup slight list_entry abuse

2015-06-23T22:01:59+00:00

list_entry is just a wrapper for container_of, but it is arguably
wrong (and slightly confusing) to use it when the pointed-to struct
member is not a struct list_head. Use container_of directly instead.

Signed-off-by: Rasmus Villemoes 
Signed-off-by: Al Viro

VFS: normal filesystems (and lustre): d_inode() annotations

2015-04-15T19:06:57+00:00

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells 
Signed-off-by: Al Viro