[PATCH 5.11 314/601] afs: Fix updating of i_mode due to 3rd party change

Greg Kroah-Hartman
2021-05-12T17:31:07Z

From: David Howells <dhowells@redhat.com>

[ Upstream commit 6e1eb04a87f954eb06a89ee6034c166351dfff6e ]

Fix afs_apply_status() to mask off the irrelevant bits from status->mode
when OR'ing them into i_mode. This can happen when a 3rd party chmod
occurs.

Also fix afs_inode_init_from_status() to mask off the mode bits when
initialising i_mode.

Fixes: 260a980317da ("[AFS]: Add "directory write" support.")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/afs/inode.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 1d03eb1920ec..bf44e245d7dc 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -102,13 +102,13 @@ static int afs_inode_init_from_status(struct afs_operation *op,

switch (status->type) {
case AFS_FTYPE_FILE:
- inode->i_mode = S_IFREG | status->mode;
+ inode->i_mode = S_IFREG | (status->mode & S_IALLUGO);
inode->i_op = &afs_file_inode_operations;
inode->i_fop = &afs_file_operations;
inode->i_mapping->a_ops = &afs_fs_aops;
break;
case AFS_FTYPE_DIR:
- inode->i_mode = S_IFDIR | status->mode;
+ inode->i_mode = S_IFDIR | (status->mode & S_IALLUGO);
inode->i_op = &afs_dir_inode_operations;
inode->i_fop = &afs_dir_file_operations;
inode->i_mapping->a_ops = &afs_dir_aops;
@@ -198,7 +198,7 @@ static void afs_apply_status(struct afs_operation *op,
if (status->mode != vnode->status.mode) {
mode = inode->i_mode;
mode &= ~S_IALLUGO;
- mode |= status->mode;
+ mode |= status->mode & S_IALLUGO;
WRITE_ONCE(inode->i_mode, mode);
}

--
2.30.2