CVE-2023-53457

In the Linux kernel, the following vulnerability has been resolved:

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.