This is a note to let you know that I've just added the patch titled
FS: JFS: Check for read-only mounted filesystem in txBegin
to the 5.4-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:
fs-jfs-check-for-read-only-mounted-filesystem-in-txb.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit bc22fdbbae03d7a4ecf10c426b62662ac8f747bf
Author: Immad Mir <mirimmad17@xxxxxxxxx>
Date: Fri Jun 23 19:17:08 2023 +0530
FS: JFS: Check for read-only mounted filesystem in txBegin
[ Upstream commit 95e2b352c03b0a86c5717ba1d24ea20969abcacc ]
This patch adds a check for read-only mounted filesystem
in txBegin before starting a transaction potentially saving
from NULL pointer deref.
Signed-off-by: Immad Mir <mirimmad17@xxxxxxxxx>
Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index c8ce7f1bc5942..6f6a5b9203d3f 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -354,6 +354,11 @@ tid_t txBegin(struct super_block *sb, int flag)
jfs_info("txBegin: flag = 0x%x", flag);
log = JFS_SBI(sb)->log;
+ if (!log) {
+ jfs_error(sb, "read-only filesystem\n");
+ return 0;
+ }
+
TXN_LOCK();
INCREMENT(TxStat.txBegin);
