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| author | Christian Brauner <brauner@kernel.org> | 2024-09-25 12:05:16 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-14 21:51:34 +0300 |
| commit | ac98b8c1034686ea6dd803b46fc0ad687430c712 (patch) | |
| tree | fb97e2a285e9d4336b177ee5fdab148c330c3c89 /include/linux | |
| parent | dc02407ea952e20c544a078a6be2e6f008327973 (diff) | |
| download | linux-ac98b8c1034686ea6dd803b46fc0ad687430c712.tar.xz | |
epoll: annotate racy check
[ Upstream commit 6474353a5e3d0b2cf610153cea0c61f576a36d0a ]
Epoll relies on a racy fastpath check during __fput() in
eventpoll_release() to avoid the hit of pointlessly acquiring a
semaphore. Annotate that race by using WRITE_ONCE() and READ_ONCE().
Link: https://lore.kernel.org/r/66edfb3c.050a0220.3195df.001a.GAE@google.com
Link: https://lore.kernel.org/r/20240925-fungieren-anbauen-79b334b00542@brauner
Reviewed-by: Jan Kara <jack@suse.cz>
Reported-by: syzbot+3b6b32dc50537a49bb4a@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/eventpoll.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h index 3337745d81bd..0c0d00fcd131 100644 --- a/include/linux/eventpoll.h +++ b/include/linux/eventpoll.h @@ -42,7 +42,7 @@ static inline void eventpoll_release(struct file *file) * because the file in on the way to be removed and nobody ( but * eventpoll ) has still a reference to this file. */ - if (likely(!file->f_ep)) + if (likely(!READ_ONCE(file->f_ep))) return; /* |