Commit 3f61631d47f1 for kernel

commit 3f61631d47f115b83c935d0039f95cb68b0c8ab7
Author: Al Viro <viro@zeniv.linux.org.uk>
Date:   Sun Aug 14 15:16:18 2022 -0400

    take care to handle NULL ->proc_lseek()

    Easily done now, just by clearing FMODE_LSEEK in ->f_mode
    during proc_reg_open() for such entries.

    Fixes: 868941b14441 "fs: remove no_llseek"
    Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index f130499ad843..f495fdb39151 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -494,6 +494,9 @@ static int proc_reg_open(struct inode *inode, struct file *file)
 	typeof_member(struct proc_ops, proc_release) release;
 	struct pde_opener *pdeo;

+	if (!pde->proc_ops->proc_lseek)
+		file->f_mode &= ~FMODE_LSEEK;
+
 	if (pde_is_permanent(pde)) {
 		open = pde->proc_ops->proc_open;
 		if (open)