The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 47a1db8e797da01a1309bf42e0c0d771d4e4d4f3 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@xxxxxxxxxx>
Date: Wed, 1 Dec 2021 14:25:26 +0100
Subject: [PATCH] firmware: qemu_fw_cfg: fix kobject leak in probe error path
An initialised kobject must be freed using kobject_put() to avoid
leaking associated resources (e.g. the object name).
Commit fe3c60684377 ("firmware: Fix a reference count leak.") "fixed"
the leak in the first error path of the file registration helper but
left the second one unchanged. This "fix" would however result in a NULL
pointer dereference due to the release function also removing the never
added entry from the fw_cfg_entry_cache list. This has now been
addressed.
Fix the remaining kobject leak by restoring the common error path and
adding the missing kobject_put().
Fixes: 75f3e8e47f38 ("firmware: introduce sysfs driver for QEMU's fw_cfg device")
Cc: stable@xxxxxxxxxxxxxxx # 4.6
Cc: Gabriel Somlo <somlo@xxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211201132528.30025-3-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
index a9c64ebfc49a..ccb7ed62452f 100644
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -603,15 +603,13 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f)
/* register entry under "/sys/firmware/qemu_fw_cfg/by_key/" */
err = kobject_init_and_add(&entry->kobj, &fw_cfg_sysfs_entry_ktype,
fw_cfg_sel_ko, "%d", entry->select);
- if (err) {
- kobject_put(&entry->kobj);
- return err;
- }
+ if (err)
+ goto err_put_entry;
/* add raw binary content access */
err = sysfs_create_bin_file(&entry->kobj, &fw_cfg_sysfs_attr_raw);
if (err)
- goto err_add_raw;
+ goto err_del_entry;
/* try adding "/sys/firmware/qemu_fw_cfg/by_name/" symlink */
fw_cfg_build_symlink(fw_cfg_fname_kset, &entry->kobj, entry->name);
@@ -620,9 +618,10 @@ static int fw_cfg_register_file(const struct fw_cfg_file *f)
fw_cfg_sysfs_cache_enlist(entry);
return 0;
-err_add_raw:
+err_del_entry:
kobject_del(&entry->kobj);
- kfree(entry);
+err_put_entry:
+ kobject_put(&entry->kobj);
return err;
}
