Many filesystems lock inodes before calling vfs_getattr, so there is no
data-race for inodes. However, some functions in fs/stat.c that call
vfs_getattr do not lock inodes, so the data-race occurs.
Therefore, we need to apply a patch to remove the long-standing data-race
for inodes in some functions that do not lock inodes.
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: da9aa5d96bfe ("fs: remove vfs_statx_fd")
Fixes: 0ef625bba6fb ("vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)")
Signed-off-by: Jeongjun Park <aha310510@xxxxxxxxx>
---
fs/stat.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/fs/stat.c b/fs/stat.c
index 41e598376d7e..da532b611aa3 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -220,13 +220,21 @@ EXPORT_SYMBOL(vfs_getattr);
*/
int vfs_fstat(int fd, struct kstat *stat)
{
+ const struct path *path;
+ struct inode *inode;
struct fd f;
int error;
f = fdget_raw(fd);
if (!fd_file(f))
return -EBADF;
- error = vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
+
+ path = &fd_file(f)->f_path;
+ inode = d_backing_inode(path->dentry);
+
+ inode_lock_shared(inode);
+ error = vfs_getattr(path, stat, STATX_BASIC_STATS, 0);
+ inode_unlock_shared(inode);
fdput(f);
return error;
}
@@ -248,7 +256,11 @@ int getname_statx_lookup_flags(int flags)
static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
u32 request_mask)
{
+ struct inode *inode = d_backing_inode(path->dentry);
+
+ inode_lock_shared(inode);
int error = vfs_getattr(path, stat, request_mask, flags);
+ inode_unlock_shared(inode);
if (request_mask & STATX_MNT_ID_UNIQUE) {
stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
--
