From 300b072df72694ea330c4c673c035253e07827b8 Mon Sep 17 00:00:00 2001 From: Shaurya Rane Date: Mon, 25 Aug 2025 01:43:32 +0530 Subject: [PATCH] jfs: fix uninitialized waitqueue in transaction manager The transaction manager initialization in txInit() was not properly initializing TxBlock[0].waitor waitqueue, causing a crash when txEnd(0) is called on read-only filesystems. When a filesystem is mounted read-only, txBegin() returns tid=0 to indicate no transaction. However, txEnd(0) still gets called and tries to access TxBlock[0].waitor via tid_to_tblock(0), but this waitqueue was never initialized because the initialization loop started at index 1 instead of 0. This causes a 'non-static key' lockdep warning and system crash: INFO: trying to register non-static key in txEnd Fix by ensuring all transaction blocks including TxBlock[0] have their waitqueues properly initialized during txInit(). Reported-by: syzbot+c4f3462d8b2ad7977bea@syzkaller.appspotmail.com Signed-off-by: Shaurya Rane Signed-off-by: Dave Kleikamp --- fs/jfs/jfs_txnmgr.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c index be17e3c43582f..7840a03e5bcb7 100644 --- a/fs/jfs/jfs_txnmgr.c +++ b/fs/jfs/jfs_txnmgr.c @@ -272,14 +272,15 @@ int txInit(void) if (TxBlock == NULL) return -ENOMEM; - for (k = 1; k < nTxBlock - 1; k++) { - TxBlock[k].next = k + 1; + for (k = 0; k < nTxBlock; k++) { init_waitqueue_head(&TxBlock[k].gcwait); init_waitqueue_head(&TxBlock[k].waitor); } + + for (k = 1; k < nTxBlock - 1; k++) { + TxBlock[k].next = k + 1; + } TxBlock[k].next = 0; - init_waitqueue_head(&TxBlock[k].gcwait); - init_waitqueue_head(&TxBlock[k].waitor); TxAnchor.freetid = 1; init_waitqueue_head(&TxAnchor.freewait); -- 2.47.3