From 32e5a2a2be6b085febaac36efff495ad65a55e6c Mon Sep 17 00:00:00 2001 From: Joseph Qi Date: Thu, 6 Aug 2015 15:46:48 -0700 Subject: [PATCH] ocfs2: fix shift left overflow When using a large volume, for example 9T volume with 2T already used, frequent creation of small files with O_DIRECT when the IO is not cluster aligned may clear sectors in the wrong place. This will cause filesystem corruption. This is because p_cpos is a u32. When calculating the corresponding sector it should be converted to u64 first, otherwise it may overflow. Signed-off-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: [4.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/aops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 1a35c6139656..0f5fd9db8194 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -685,7 +685,7 @@ static int ocfs2_direct_IO_zero_extend(struct ocfs2_super *osb, if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN)) { u64 s = i_size_read(inode); - sector_t sector = (p_cpos << (osb->s_clustersize_bits - 9)) + + sector_t sector = ((u64)p_cpos << (osb->s_clustersize_bits - 9)) + (do_div(s, osb->s_clustersize) >> 9); ret = blkdev_issue_zeroout(osb->sb->s_bdev, sector, @@ -910,7 +910,7 @@ static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb, BUG_ON(!p_cpos || (ext_flags & OCFS2_EXT_UNWRITTEN)); ret = blkdev_issue_zeroout(osb->sb->s_bdev, - p_cpos << (osb->s_clustersize_bits - 9), + (u64)p_cpos << (osb->s_clustersize_bits - 9), zero_len_head >> 9, GFP_NOFS, false); if (ret < 0) mlog_errno(ret); -- 2.20.1