[PATCH 4.9 003/134] ntfs: check for valid standard information attribute
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-03-01 17:18:33
Also in:
lkml
From: Rustam Kovhaev <redacted> commit 4dfe6bd94959222e18d512bdf15f6bf9edb9c27c upstream. Mounting a corrupted filesystem with NTFS resulted in a kernel crash. We should check for valid STANDARD_INFORMATION attribute offset and length before trying to access it Link: https://lkml.kernel.org/r/20210217155930.1506815-1-rkovhaev@gmail.com Link: https://syzkaller.appspot.com/bug?extid=c584225dabdea2f71969 Signed-off-by: Rustam Kovhaev <redacted> Reported-by: syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com Tested-by: syzbot+c584225dabdea2f71969@syzkaller.appspotmail.com Acked-by: Anton Altaparmakov <redacted> Cc: <redacted> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/ntfs/inode.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c@@ -661,6 +661,12 @@ static int ntfs_read_locked_inode(struct } a = ctx->attr; /* Get the standard information attribute value. */ + if ((u8 *)a + le16_to_cpu(a->data.resident.value_offset) + + le32_to_cpu(a->data.resident.value_length) > + (u8 *)ctx->mrec + vol->mft_record_size) { + ntfs_error(vi->i_sb, "Corrupt standard information attribute in inode."); + goto unm_err_out; + } si = (STANDARD_INFORMATION*)((u8*)a + le16_to_cpu(a->data.resident.value_offset));