jfs: fix uaf in jfs_evict_inode
When the execution of diMount(ipimap) fails, the object ipimap that has been
released may be accessed in diFreeSpecial(). Asynchronous ipimap release occurs
when rcu_core() calls jfs_free_node().
Therefore, when diMount(ipimap) fails, sbi->ipimap should not be initialized as
ipimap.
Reported-and-tested-by: syzbot+01cf2dbcbe2022454388@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
diff --git a/fs/jfs/jfs_mount.c b/fs/jfs/jfs_mount.c
index 415eb65..9b5c6a2 100644
--- a/fs/jfs/jfs_mount.c
+++ b/fs/jfs/jfs_mount.c
@@ -172,15 +172,15 @@ int jfs_mount(struct super_block *sb)
}
jfs_info("jfs_mount: ipimap:0x%p", ipimap);
- /* map further access of per fileset inodes by the fileset inode */
- sbi->ipimap = ipimap;
-
/* initialize fileset inode allocation map */
if ((rc = diMount(ipimap))) {
jfs_err("jfs_mount: diMount failed w/rc = %d", rc);
goto err_ipimap;
}
+ /* map further access of per fileset inodes by the fileset inode */
+ sbi->ipimap = ipimap;
+
return rc;
/*
