CVE-2024-49900

jfs: Fix uninit-value access of new_ea in ea_buffer

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uninit-value access of new_ea in ea_buffer syzbot reports that lzo1x_1_do_compress is using uninit-value: ===================================================== BUG: KMSAN: uninit-value in lzo1x_1_do_compress+0x19f9/0x2510 lib/lzo/lzo1x_compress.c:178 ... Uninit was stored to memory at: ea_put fs/jfs/xattr.c:639 [inline] ... Local variable ea_buf created at: __jfs_setxattr+0x5d/0x1ae0 fs/jfs/xattr.c:662 __jfs_xattr_set+0xe6/0x1f0 fs/jfs/xattr.c:934 ===================================================== The reason is ea_buf->new_ea is not initialized properly. Fix this by using memset to empty its content at the beginning in ea_get().