From 4801672fb076d546c67504ec9810a3a467e91768 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 23 Nov 2022 09:10:42 +0100 Subject: [PATCH] fuse: lock inode unconditionally in fuse_fallocate() commit 44361e8cf9ddb23f17bdcc40ca944abf32e83e79 upstream. file_modified() must be called with inode lock held. fuse_fallocate() didn't lock the inode in case of just FALLOC_KEEP_SIZE flags value, which resulted in a kernel Warning in notify_change(). Lock the inode unconditionally, like all other fallocate implementations do. Reported-by: Pengfei Xu Reported-and-tested-by: syzbot+462da39f0667b357c4b6@syzkaller.appspotmail.com Fixes: 4a6f278d4827 ("fuse: add file_modified() to fallocate") Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/fuse/file.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 253308fcb047..504389568dac 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -3275,10 +3275,9 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, .mode = mode }; int err; - bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) || - (mode & FALLOC_FL_PUNCH_HOLE); - - bool block_faults = FUSE_IS_DAX(inode) && lock_inode; + bool block_faults = FUSE_IS_DAX(inode) && + (!(mode & FALLOC_FL_KEEP_SIZE) || + (mode & FALLOC_FL_PUNCH_HOLE)); if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) return -EOPNOTSUPP; @@ -3286,22 +3285,20 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, if (fm->fc->no_fallocate) return -EOPNOTSUPP; - if (lock_inode) { - inode_lock(inode); - if (block_faults) { - down_write(&fi->i_mmap_sem); - err = fuse_dax_break_layouts(inode, 0, 0); - if (err) - goto out; - } + inode_lock(inode); + if (block_faults) { + down_write(&fi->i_mmap_sem); + err = fuse_dax_break_layouts(inode, 0, 0); + if (err) + goto out; + } - if (mode & FALLOC_FL_PUNCH_HOLE) { - loff_t endbyte = offset + length - 1; + if (mode & FALLOC_FL_PUNCH_HOLE) { + loff_t endbyte = offset + length - 1; - err = fuse_writeback_range(inode, offset, endbyte); - if (err) - goto out; - } + err = fuse_writeback_range(inode, offset, endbyte); + if (err) + goto out; } if (!(mode & FALLOC_FL_KEEP_SIZE) && @@ -3351,8 +3348,7 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset, if (block_faults) up_write(&fi->i_mmap_sem); - if (lock_inode) - inode_unlock(inode); + inode_unlock(inode); fuse_flush_time_update(inode);