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| author | Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com> | 2021-06-28 19:33:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-29 10:53:45 -0700 |
| commit | d98e4d95411bbde2220a7afa38dcc9c14d71acbe (patch) | |
| tree | 687751da151621e051978d74da3841722ee01f6f /fs/ntfs | |
| parent | c1c9142004e7e21d6d3d2cd6a339845771ce6a27 (diff) | |
| download | linux-d98e4d95411bbde2220a7afa38dcc9c14d71acbe.tar.gz linux-d98e4d95411bbde2220a7afa38dcc9c14d71acbe.tar.bz2 linux-d98e4d95411bbde2220a7afa38dcc9c14d71acbe.zip | |
ntfs: fix validity check for file name attribute
When checking the file name attribute, we want to ensure that it fits
within the bounds of ATTR_RECORD. To do this, we should check that (attr
record + file name offset + file name length) < (attr record + attr record
length).
However, the original check did not include the file name offset in the
calculation. This means that corrupted on-disk metadata might not caught
by the incorrect file name check, and lead to an invalid memory access.
An example can be seen in the crash report of a memory corruption error
found by Syzbot:
https://syzkaller.appspot.com/bug?id=a1a1e379b225812688566745c3e2f7242bffc246
Adding the file name offset to the validity check fixes this error and
passes the Syzbot reproducer test.
Link: https://lkml.kernel.org/r/20210614050540.289494-1-desmondcheongzx@gmail.com
Signed-off-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reported-by: syzbot+213ac8bb98f7f4420840@syzkaller.appspotmail.com
Tested-by: syzbot+213ac8bb98f7f4420840@syzkaller.appspotmail.com
Acked-by: Anton Altaparmakov <anton@tuxera.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ntfs')
| -rw-r--r-- | fs/ntfs/inode.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c index f5c058b3192c..4474adb393ca 100644 --- a/fs/ntfs/inode.c +++ b/fs/ntfs/inode.c @@ -477,7 +477,7 @@ err_corrupt_attr: } file_name_attr = (FILE_NAME_ATTR*)((u8*)attr + le16_to_cpu(attr->data.resident.value_offset)); - p2 = (u8*)attr + le32_to_cpu(attr->data.resident.value_length); + p2 = (u8 *)file_name_attr + le32_to_cpu(attr->data.resident.value_length); if (p2 < (u8*)attr || p2 > p) goto err_corrupt_attr; /* This attribute is ok, but is it in the $Extend directory? */ |