This is a note to let you know that I've just added the patch titled fs/ntfs3: don't hold ni_lock when calling truncate_setsize() to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fs-ntfs3-don-t-hold-ni_lock-when-calling-truncate_se.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 528377551f17f7fdea681861daac24e0c32acbb9 Author: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Date: Mon Jan 2 23:05:33 2023 +0900 fs/ntfs3: don't hold ni_lock when calling truncate_setsize() [ Upstream commit 0226635c304cfd5c9db9b78c259cb713819b057e ] syzbot is reporting hung task at do_user_addr_fault() [1], for there is a silent deadlock between PG_locked bit and ni_lock lock. Since filemap_update_page() calls filemap_read_folio() after calling folio_trylock() which will set PG_locked bit, ntfs_truncate() must not call truncate_setsize() which will wait for PG_locked bit to be cleared when holding ni_lock lock. Link: https://lore.kernel.org/all/00000000000060d41f05f139aa44@xxxxxxxxxx/ Link: https://syzkaller.appspot.com/bug?extid=bed15dbf10294aa4f2ae [1] Reported-by: syzbot <syzbot+bed15dbf10294aa4f2ae@xxxxxxxxxxxxxxxxxxxxxxxxx> Debugged-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Co-developed-by: Hillf Danton <hdanton@xxxxxxxx> Signed-off-by: Hillf Danton <hdanton@xxxxxxxx> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c index 4f2ffc7ef296..f31c0389a2e7 100644 --- a/fs/ntfs3/file.c +++ b/fs/ntfs3/file.c @@ -486,10 +486,10 @@ static int ntfs_truncate(struct inode *inode, loff_t new_size) new_valid = ntfs_up_block(sb, min_t(u64, ni->i_valid, new_size)); - ni_lock(ni); - truncate_setsize(inode, new_size); + ni_lock(ni); + down_write(&ni->file.run_lock); err = attr_set_size(ni, ATTR_DATA, NULL, 0, &ni->file.run, new_size, &new_valid, ni->mi.sbi->options->prealloc, NULL);