This is a note to let you know that I've just added the patch titled
cachefiles: propagate errors from vfs_getxattr() to avoid infinite loop
to the 6.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cachefiles-propagate-errors-from-vfs_getxattr-to-avo.patch
and it can be found in the queue-6.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d47a352fe8600270cf3da4df70547c44fd45364a
Author: Baokun Li <libaokun1@xxxxxxxxxx>
Date: Fri Jun 28 14:29:25 2024 +0800
cachefiles: propagate errors from vfs_getxattr() to avoid infinite loop
[ Upstream commit 0ece614a52bc9d219b839a6a29282b30d10e0c48 ]
In cachefiles_check_volume_xattr(), the error returned by vfs_getxattr()
is not passed to ret, so it ends up returning -ESTALE, which leads to an
endless loop as follows:
cachefiles_acquire_volume
retry:
ret = cachefiles_check_volume_xattr
ret = -ESTALE
xlen = vfs_getxattr // return -EIO
// The ret is not updated when xlen < 0, so -ESTALE is returned.
return ret
// Supposed to jump out of the loop at this judgement.
if (ret != -ESTALE)
goto error_dir;
cachefiles_bury_object
// EIO causes rename failure
goto retry;
Hence propagate the error returned by vfs_getxattr() to avoid the above
issue. Do the same in cachefiles_check_auxdata().
Fixes: 32e150037dce ("fscache, cachefiles: Store the volume coherency data")
Fixes: 72b957856b0c ("cachefiles: Implement metadata/coherency data storage in xattrs")
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240628062930.2467993-5-libaokun@xxxxxxxxxxxxxxx
Reviewed-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index bcb6173943ee4..4dd8a993c60a8 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -110,9 +110,11 @@ int cachefiles_check_auxdata(struct cachefiles_object *object, struct file *file
if (xlen == 0)
xlen = vfs_getxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache, buf, tlen);
if (xlen != tlen) {
- if (xlen < 0)
+ if (xlen < 0) {
+ ret = xlen;
trace_cachefiles_vfs_error(object, file_inode(file), xlen,
cachefiles_trace_getxattr_error);
+ }
if (xlen == -EIO)
cachefiles_io_error_obj(
object,
@@ -252,6 +254,7 @@ int cachefiles_check_volume_xattr(struct cachefiles_volume *volume)
xlen = vfs_getxattr(&nop_mnt_idmap, dentry, cachefiles_xattr_cache, buf, len);
if (xlen != len) {
if (xlen < 0) {
+ ret = xlen;
trace_cachefiles_vfs_error(NULL, d_inode(dentry), xlen,
cachefiles_trace_getxattr_error);
if (xlen == -EIO)
