Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 65/84] ocfs2: fix shift left overflow | Date | Fri, 14 Aug 2015 10:42:33 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Joseph Qi <joseph.qi@huawei.com>
commit 32e5a2a2be6b085febaac36efff495ad65a55e6c upstream.
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 <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> 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/ocfs2/aops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -686,7 +686,7 @@ static int ocfs2_direct_IO_zero_extend(s 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, @@ -911,7 +911,7 @@ static ssize_t ocfs2_direct_IO_write(str 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);
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