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.
