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authorDesmond Cheong Zhi Xi <desmondcheongzx@gmail.com>2021-06-28 19:33:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-29 10:53:45 -0700
commitd98e4d95411bbde2220a7afa38dcc9c14d71acbe (patch)
tree687751da151621e051978d74da3841722ee01f6f /fs/ntfs
parentscripts/spelling.txt: add more spellings to spelling.txt (diff)
downloadlinux-dev-d98e4d95411bbde2220a7afa38dcc9c14d71acbe.tar.xz
linux-dev-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.c2
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? */