From: Su Yue glass.su@suse.com

mainline inclusion from mainline-v6.10-rc1 commit 952b023f06a24b2ad6ba67304c4c84d45bea2f18 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAD0L1 CVE: CVE-2024-40943

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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After commit "ocfs2: return real error code in ocfs2_dio_wr_get_block", fstests/generic/300 become from always failed to sometimes failed:

======================================================================== [ 473.293420 ] run fstests generic/300

[ 475.296983 ] JBD2: Ignoring recovery information on journal [ 475.302473 ] ocfs2: Mounting device (253,1) on (node local, slot 0) with ordered data mode. [ 494.290998 ] OCFS2: ERROR (device dm-1): ocfs2_change_extent_flag: Owner 5668 has an extent at cpos 78723 which can no longer be found [ 494.291609 ] On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted. [ 494.292018 ] OCFS2: File system is now read-only. [ 494.292224 ] (kworker/19:11,2628,19):ocfs2_mark_extent_written:5272 ERROR: status = -30 [ 494.292602 ] (kworker/19:11,2628,19):ocfs2_dio_end_io_write:2374 ERROR: status = -3 fio: io_u error on file /mnt/scratch/racer: Read-only file system: write offset=460849152, buflen=131072 =========================================================================

In __blockdev_direct_IO, ocfs2_dio_wr_get_block is called to add unwritten extents to a list. extents are also inserted into extent tree in ocfs2_write_begin_nolock. Then another thread call fallocate to puch a hole at one of the unwritten extent. The extent at cpos was removed by ocfs2_remove_extent(). At end io worker thread, ocfs2_search_extent_list found there is no such extent at the cpos.

T1 T2 T3 inode lock ... insert extents ... inode unlock ocfs2_fallocate __ocfs2_change_file_space inode lock lock ip_alloc_sem ocfs2_remove_inode_range inode ocfs2_remove_btree_range ocfs2_remove_extent ^---remove the extent at cpos 78723 ... unlock ip_alloc_sem inode unlock ocfs2_dio_end_io ocfs2_dio_end_io_write lock ip_alloc_sem ocfs2_mark_extent_written ocfs2_change_extent_flag ocfs2_search_extent_list ^---failed to find extent ... unlock ip_alloc_sem

In most filesystems, fallocate is not compatible with racing with AIO+DIO, so fix it by adding to wait for all dio before fallocate/punch_hole like ext4.

Link: https://lkml.kernel.org/r/20240408082041.20925-3-glass.su@suse.com Fixes: b25801038da5 ("ocfs2: Support xfs style space reservation ioctls") Signed-off-by: Su Yue glass.su@suse.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Joel Becker jlbec@evilplan.org Cc: Jun Piao piaojun@huawei.com Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Mark Fasheh mark@fasheh.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Ye Bin yebin10@huawei.com --- fs/ocfs2/file.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 318b73d791d5..ec0e67e9a3ec 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1940,6 +1940,8 @@ static int __ocfs2_change_file_space(struct file *file, struct inode *inode,

inode_lock(inode);

+ /* Wait all existing dio workers, newcomers will block on i_rwsem */ + inode_dio_wait(inode); /* * This prevents concurrent writes on other nodes */