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authorImmad Mir <mirimmad17@gmail.com>2023-06-23 15:44:01 +0200
committerDave Kleikamp <dave.kleikamp@oracle.com>2023-06-23 16:00:13 +0200
commit47cfdc338d674d38f4b2f22b7612cc6a2763ba27 (patch)
tree5c6d4b0ab2b5eaddcaf170a8d2a450d1bd3ad29f /fs/jfs
parentfs: jfs: Fix UBSAN: array-index-out-of-bounds in dbAllocDmapLev (diff)
downloadlinux-47cfdc338d674d38f4b2f22b7612cc6a2763ba27.tar.xz
linux-47cfdc338d674d38f4b2f22b7612cc6a2763ba27.zip
FS: JFS: Fix null-ptr-deref Read in txBegin
Syzkaller reported an issue where txBegin may be called on a superblock in a read-only mounted filesystem which leads to NULL pointer deref. This could be solved by checking if the filesystem is read-only before calling txBegin, and returning with appropiate error code. Reported-By: syzbot+f1faa20eec55e0c8644c@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=be7e52c50c5182cc09a09ea6fc456446b2039de3 Signed-off-by: Immad Mir <mirimmad17@gmail.com> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Diffstat (limited to 'fs/jfs')
-rw-r--r--fs/jfs/namei.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index b29d68b5eec5..f370c7605120 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -799,6 +799,11 @@ static int jfs_link(struct dentry *old_dentry,
if (rc)
goto out;
+ if (isReadOnly(ip)) {
+ jfs_error(ip->i_sb, "read-only filesystem\n");
+ return -EROFS;
+ }
+
tid = txBegin(ip->i_sb, 0);
mutex_lock_nested(&JFS_IP(dir)->commit_mutex, COMMIT_MUTEX_PARENT);