Re: [f2fs-dev] [PATCH] f2fs: fix kernel crash due to null io->bio

From: Chao Yu
Date: Tue Feb 07 2023 - 07:35:45 EST


On 2023/2/6 11:43, Jaegeuk Kim wrote:
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>

Cc: stable@xxxxxxxxxxxxxxx # v5.18+
Fixes: 64bf0eef0171 ("f2fs: pass the bio operation to bio_alloc_bioset")
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,