kernel/linux.git/fs/squashfs, branch linux-4.4.y

squashfs: fix divide error in calculate_skip()

2021-05-22T08:38:29+00:00

commit d6e621de1fceb3b098ebf435ef7ea91ec4838a1a upstream. Sysbot has reported a "divide error" which has been identified as being caused by a corrupted file_size value within the file inode. This value has been corrupted to a much larger value than expected. Calculate_skip() is passed i_size_read(inode) >> msblk->block_log. Due to the file_size value corruption this overflows the int argument/variable in that function, leading to the divide error. This patch changes the function to use u64. This will accommodate any unexpectedly large values due to corruption. The value returned from calculate_skip() is clamped to be never more than SQUASHFS_CACHED_BLKS - 1, or 7. So file_size corruption does not lead to an unexpectedly large return result here. Link: https://lkml.kernel.org/r/20210507152618.9447-1-phillip@squashfs.org.uk Signed-off-by: Phillip Lougher Reported-by: Reported-by: Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

squashfs: fix xattr id and id lookup sanity checks

2021-03-30T12:45:00+00:00

commit 8b44ca2b634527151af07447a8090a5f3a043321 upstream. The checks for maximum metadata block size is missing SQUASHFS_BLOCK_OFFSET (the two byte length count). Link: https://lkml.kernel.org/r/2069685113.2081245.1614583677427@webmail.123-reg.co.uk Fixes: f37aa4c7366e23f ("squashfs: add more sanity checks in id lookup") Signed-off-by: Phillip Lougher Cc: Sean Nyekjaer Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

squashfs: fix inode lookup sanity checks

2021-03-30T12:44:59+00:00

commit c1b2028315c6b15e8d6725e0d5884b15887d3daa upstream. When mouting a squashfs image created without inode compression it fails with: "unable to read inode lookup table" It turns out that the BLOCK_OFFSET is missing when checking the SQUASHFS_METADATA_SIZE agaist the actual size. Link: https://lkml.kernel.org/r/20210226092903.1473545-1-sean@geanix.com Fixes: eabac19e40c0 ("squashfs: add more sanity checks in inode lookup") Signed-off-by: Sean Nyekjaer Acked-by: Phillip Lougher Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

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