In the Linux kernel, the following vulnerability has been resolved: f2fs: fix kernel crash due to null io->bio We should return when io->bio is null before doing anything. Otherwise, panic. BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: 0010:__submit_merged_write_cond+0x164/0x240 [f2fs] Call Trace: <TASK> f2fs_submit_merged_write+0x1d/0x30 [f2fs] commit_checkpoint+0x110/0x1e0 [f2fs] f2fs_write_checkpoint+0x9f7/0xf00 [f2fs] ? __pfx_issue_checkpoint_thread+0x10/0x10 [f2fs] __checkpoint_and_complete_reqs+0x84/0x190 [f2fs] ? preempt_count_add+0x82/0xc0 ? __pfx_issue_checkpoint_thread+0x10/0x10 [f2fs] issue_checkpoint_thread+0x4c/0xf0 [f2fs] ? __pfx_autoremove_wake_function+0x10/0x10 kthread+0xff/0x130 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK>