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| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2020-10-02 14:17:35 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-05 11:43:14 +0100 |
| commit | df5b07f2172a159a4d9f0c280e6ecddba992ba35 (patch) | |
| tree | 71ec8d2cdc36ace8f9998f1c180f50ac9a8f60de /fs/f2fs/checkpoint.c | |
| parent | 15c7ec03ddb8ec7990d9d903cf29c0afa33403be (diff) | |
f2fs: handle errors of f2fs_get_meta_page_nofail
[ Upstream commit 86f33603f8c51537265ff7ac0320638fd2cbdb1b ]
First problem is we hit BUG_ON() in f2fs_get_sum_page given EIO on
f2fs_get_meta_page_nofail().
Quick fix was not to give any error with infinite loop, but syzbot caught
a case where it goes to that loop from fuzzed image. In turned out we abused
f2fs_get_meta_page_nofail() like in the below call stack.
- f2fs_fill_super
- f2fs_build_segment_manager
- build_sit_entries
- get_current_sit_page
INFO: task syz-executor178:6870 can't die for more than 143 seconds.
task:syz-executor178 state:R
stack:26960 pid: 6870 ppid: 6869 flags:0x00004006
Call Trace:
Showing all locks held in the system:
1 lock held by khungtaskd/1179:
#0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6242
1 lock held by systemd-journal/3920:
1 lock held by in:imklog/6769:
#0: ffff88809eebc130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
1 lock held by syz-executor178/6870:
#0: ffff8880925120e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229
Actually, we didn't have to use _nofail in this case, since we could return
error to mount(2) already with the error handler.
As a result, this patch tries to 1) remove _nofail callers as much as possible,
2) deal with error case in last remaining caller, f2fs_get_sum_page().
Reported-by: syzbot+ee250ac8137be41d7b13@syzkaller.appspotmail.com
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/f2fs/checkpoint.c')
| -rw-r--r-- | fs/f2fs/checkpoint.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 6d9be7783d25..c966ccc44c15 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -108,7 +108,7 @@ struct page *f2fs_get_meta_page(struct f2fs_sb_info *sbi, pgoff_t index) return __get_meta_page(sbi, index, true); } -struct page *f2fs_get_meta_page_nofail(struct f2fs_sb_info *sbi, pgoff_t index) +struct page *f2fs_get_meta_page_retry(struct f2fs_sb_info *sbi, pgoff_t index) { struct page *page; int count = 0; |