In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix infinite loop in nilfs_clean_segments() syzbot reported a hung task in nilfs_transaction_begin(). This occurs because the cleaner ioctl falls into an infinite loop if nilfs_segctor_construct() repeatedly returns -EROFS (e.g. the device is remounted as read-only after an I/O error). Currently in nilfs_clean_segments(), if err is non-zero, it logs the error and sleeps but doesn't abort when it encounters a terminal error like -EROFS. This causes the thread to loop forever. Fix this by breaking out of the loop if nilfs_segctor_construct() returns -EROFS. This matches the behaviour in nilfs_segctor_write_out(), which also handles -EROFS.
nilfs2: fix infinite loop in nilfs_clean_segments()