This is a note to let you know that I've just added the patch titled
ksmbd: fix race condition from parallel smb2 lock requests
to the 6.5-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:
ksmbd-fix-race-condition-from-parallel-smb2-lock-requests.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 75ac9a3dd65f7eab4d12b0a0f744234b5300a491 Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Date: Wed, 4 Oct 2023 18:31:03 +0900
Subject: ksmbd: fix race condition from parallel smb2 lock requests
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
commit 75ac9a3dd65f7eab4d12b0a0f744234b5300a491 upstream.
There is a race condition issue between parallel smb2 lock request.
Time
+
Thread A | Thread A
smb2_lock | smb2_lock
|
insert smb_lock to lock_list |
spin_unlock(&work->conn->llist_lock) |
|
| spin_lock(&conn->llist_lock);
| kfree(cmp_lock);
|
// UAF! |
list_add(&smb_lock->llist, &rollback_list) +
This patch swaps the line for adding the smb lock to the rollback list and
adding the lock list of connection to fix the race issue.
Reported-by: luosili <rootlab@xxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/smb/server/smb2pdu.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -7029,10 +7029,6 @@ skip:
ksmbd_debug(SMB,
"would have to wait for getting lock\n");
- spin_lock(&work->conn->llist_lock);
- list_add_tail(&smb_lock->clist,
- &work->conn->lock_list);
- spin_unlock(&work->conn->llist_lock);
list_add(&smb_lock->llist, &rollback_list);
argv = kmalloc(sizeof(void *), GFP_KERNEL);
@@ -7063,9 +7059,6 @@ skip:
if (work->state != KSMBD_WORK_ACTIVE) {
list_del(&smb_lock->llist);
- spin_lock(&work->conn->llist_lock);
- list_del(&smb_lock->clist);
- spin_unlock(&work->conn->llist_lock);
locks_free_lock(flock);
if (work->state == KSMBD_WORK_CANCELLED) {
@@ -7087,19 +7080,16 @@ skip:
}
list_del(&smb_lock->llist);
- spin_lock(&work->conn->llist_lock);
- list_del(&smb_lock->clist);
- spin_unlock(&work->conn->llist_lock);
release_async_work(work);
goto retry;
} else if (!rc) {
+ list_add(&smb_lock->llist, &rollback_list);
spin_lock(&work->conn->llist_lock);
list_add_tail(&smb_lock->clist,
&work->conn->lock_list);
list_add_tail(&smb_lock->flist,
&fp->lock_list);
spin_unlock(&work->conn->llist_lock);
- list_add(&smb_lock->llist, &rollback_list);
ksmbd_debug(SMB, "successful in taking lock\n");
} else {
goto out;
Patches currently in stable-queue which might be from linkinjeon@xxxxxxxxxx are
queue-6.5/ksmbd-fix-uaf-in-smb20_oplock_break_ack.patch
queue-6.5/ksmbd-fix-race-condition-from-parallel-smb2-lock-requests.patch
queue-6.5/ksmbd-fix-race-condition-between-session-lookup-and-expire.patch
