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[08/35] ocfs2: no need try to truncate file beyond i_size

Message ID 20200410213238.KttQSeJuw%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/35] hfsplus: fix crash and filesystem corruption when deleting files | expand

Commit Message

Andrew Morton April 10, 2020, 9:32 p.m. UTC 
From: Changwei Ge <chge@linux.alibaba.com>
Subject: ocfs2: no need try to truncate file beyond i_size

Linux fallocate(2) with FALLOC_FL_PUNCH_HOLE mode set, its offset can
exceed inode size.  Ocfs2 now does't allow that offset beyond inode size. 
This restriction is not necessary and voilates fallocate(2) semantics.

If fallocate(2) offset is beyond inode size, just return success and do
nothing further.

Otherwise, ocfs2 will crash the kernel.

kernel BUG at fs/ocfs2//alloc.c:7264!
 ocfs2_truncate_inline+0x20f/0x360 [ocfs2]
 ? ocfs2_read_blocks+0x2f3/0x5f0 [ocfs2]
 ocfs2_remove_inode_range+0x23c/0xcb0 [ocfs2]
 ? ocfs2_read_inode_block+0x10/0x20 [ocfs2]
 ? ocfs2_allocate_extend_trans+0x1a0/0x1a0 [ocfs2]
 __ocfs2_change_file_space+0x4a5/0x650 [ocfs2]
 ocfs2_fallocate+0x83/0xa0 [ocfs2]
 ? __audit_syscall_entry+0xb8/0x100
 ? __sb_start_write+0x3b/0x70
 vfs_fallocate+0x148/0x230
 SyS_fallocate+0x48/0x80
 do_syscall_64+0x79/0x170

Link: http://lkml.kernel.org/r/20200407082754.17565-1-chge@linux.alibaba.com
Signed-off-by: Changwei Ge <chge@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ocfs2/alloc.c |    4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

--- a/fs/ocfs2/alloc.c~ocfs2-no-need-try-to-truncate-file-beyond-i_size
+++ a/fs/ocfs2/alloc.c
@@ -7402,6 +7402,10 @@  int ocfs2_truncate_inline(struct inode *
 	struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
 	struct ocfs2_inline_data *idata = &di->id2.i_data;
 
+	/* No need to punch hole beyond i_size. */
+	if (start >= i_size_read(inode))
+		return 0;
+
 	if (end > i_size_read(inode))
 		end = i_size_read(inode);