From b6512519496e29270bca6b2df9baa3cc2d9d5356 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 22 Nov 2024 13:29:24 +0100 Subject: [PATCH] fs: require inode_owner_or_capable for F_SET_RW_HINT F_SET_RW_HINT controls data placement in the file system and / or device and should not be available to everyone who can read a given file. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20241122122931.90408-2-hch@lst.de Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/fcntl.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/fcntl.c b/fs/fcntl.c index ac77dd912412..49884fa3c81d 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -374,6 +374,9 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd, u64 __user *argp = (u64 __user *)arg; u64 hint; + if (!inode_owner_or_capable(file_mnt_idmap(file), inode)) + return -EPERM; + if (copy_from_user(&hint, argp, sizeof(hint))) return -EFAULT; if (!rw_hint_valid(hint))