6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
[ Upstream commit 844c6fdc13cf3d9d251533631988a58f8356a8c8 ]
Commit 5580cdae05ae ("ubi: wl: Close down wear-leveling before nand is
suspended") added a reboot notification in UBI layer to shutdown the
wear-leveling subsystem, which imported an UAF problem[1]. Besides that,
the method also brings other potential UAF problems, for example:
reboot kworker
ubi_wl_reboot_notifier
ubi_wl_close
ubi_fastmap_close
kfree(ubi->fm)
update_fastmap_work_fn
ubi_update_fastmap
old_fm = ubi->fm
if (old_fm && old_fm->e[i]) // UAF!
Actually, the problem fixed by commit 5580cdae05ae ("ubi: wl: Close down
wear-leveling before nand is suspended") has been solved by commit
8cba323437a4 ("mtd: rawnand: protect access to rawnand devices while in
suspend"), which was discussed in [2]. So we can revert the commit
5580cdae05ae ("ubi: wl: Close down wear-leveling before nand is
suspended") directly.
[1] https://lore.kernel.org/linux-mtd/20241208175211.9406-2-dennis.lamerice@xxxxxxxxx/
[2] https://lore.kernel.org/all/9bf76f5d-12a4-46ff-90d4-4a7f0f47c381@xxxxxxxx/
Fixes: 5580cdae05ae ("ubi: wl: Close down wear-leveling before nand is suspended")
Reported-by: Dennis Lam <dennis.lamerice@xxxxxxxxx>
Closes: https://lore.kernel.org/linux-mtd/20241208175211.9406-2-dennis.lamerice@xxxxxxxxx/
Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
Acked-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/mtd/ubi/ubi.h | 2 --
drivers/mtd/ubi/wl.c | 21 ---------------------
2 files changed, 23 deletions(-)
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 26cc53ad34ec7..c792b9bcab9bc 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -549,7 +549,6 @@ struct ubi_debug_info {
* @peb_buf: a buffer of PEB size used for different purposes
* @buf_mutex: protects @peb_buf
* @ckvol_mutex: serializes static volume checking when opening
- * @wl_reboot_notifier: close all wear-leveling work before reboot
*
* @dbg: debugging information for this UBI device
*/
@@ -652,7 +651,6 @@ struct ubi_device {
void *peb_buf;
struct mutex buf_mutex;
struct mutex ckvol_mutex;
- struct notifier_block wl_reboot_notifier;
struct ubi_debug_info dbg;
};
diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
index 4f6f339d8fb8a..fbd399cf65033 100644
--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -89,7 +89,6 @@
#include <linux/crc32.h>
#include <linux/freezer.h>
#include <linux/kthread.h>
-#include <linux/reboot.h>
#include "ubi.h"
#include "wl.h"
@@ -128,8 +127,6 @@ static int self_check_in_wl_tree(const struct ubi_device *ubi,
struct ubi_wl_entry *e, struct rb_root *root);
static int self_check_in_pq(const struct ubi_device *ubi,
struct ubi_wl_entry *e);
-static int ubi_wl_reboot_notifier(struct notifier_block *n,
- unsigned long state, void *cmd);
/**
* wl_tree_add - add a wear-leveling entry to a WL RB-tree.
@@ -1953,13 +1950,6 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
if (!ubi->ro_mode && !ubi->fm_disabled)
ubi_ensure_anchor_pebs(ubi);
#endif
-
- if (!ubi->wl_reboot_notifier.notifier_call) {
- ubi->wl_reboot_notifier.notifier_call = ubi_wl_reboot_notifier;
- ubi->wl_reboot_notifier.priority = 1; /* Higher than MTD */
- register_reboot_notifier(&ubi->wl_reboot_notifier);
- }
-
return 0;
out_free:
@@ -2005,17 +1995,6 @@ void ubi_wl_close(struct ubi_device *ubi)
kfree(ubi->lookuptbl);
}
-static int ubi_wl_reboot_notifier(struct notifier_block *n,
- unsigned long state, void *cmd)
-{
- struct ubi_device *ubi;
-
- ubi = container_of(n, struct ubi_device, wl_reboot_notifier);
- ubi_wl_close(ubi);
-
- return NOTIFY_DONE;
-}
-
/**
* self_check_ec - make sure that the erase counter of a PEB is correct.
* @ubi: UBI device description object
--
2.39.5
