]> git.ipfire.org Git - thirdparty/linux.git/commit
Revert "fsnotify: generate pre-content permission event on page fault"
authorAmir Goldstein <amir73il@gmail.com>
Wed, 12 Mar 2025 07:38:50 +0000 (08:38 +0100)
committerJan Kara <jack@suse.cz>
Thu, 13 Mar 2025 15:30:55 +0000 (16:30 +0100)
commit955fbe0ef19df4197595a98d0906c94025c4beef
treed4861dcd0c0359816ec8e520cd2ba0ea3832b2ed
parent27773ce1776279ed3220a34d2e6bfcecaee7fc66
Revert "fsnotify: generate pre-content permission event on page fault"

This reverts commit 8392bc2ff8c8bf7c4c5e6dfa71ccd893a3c046f6.

In the use case of buffered write whose input buffer is mmapped file on a
filesystem with a pre-content mark, the prefaulting of the buffer can
happen under the filesystem freeze protection (obtained in vfs_write())
which breaks assumptions of pre-content hook and introduces potential
deadlock of HSM handler in userspace with filesystem freezing.

Now that we have pre-content hooks at file mmap() time, disable the
pre-content event hooks on page fault to avoid the potential deadlock.

Reported-by: syzbot+7229071b47908b19d5b7@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-fsdevel/7ehxrhbvehlrjwvrduoxsao5k3x4aw275patsb3krkwuq573yv@o2hskrfawbnc/
Fixes: 8392bc2ff8c8 ("fsnotify: generate pre-content permission event on page fault")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250312073852.2123409-5-amir73il@gmail.com
include/linux/mm.h
mm/filemap.c
mm/nommu.c