[PATCH] proc: clear FMODE_LSEEK flag correctly for permanent pde

[wangzijie <wangzijie1@xxxxxxxxx>]

Clearing FMODE_LSEEK flag should not rely on whether proc_open ops exists, fix it.

Fixed: ad7f4ea6e36e ("proc: avoid use-after-free in proc_reg_open()")
Signed-off-by: wangzijie <wangzijie1@xxxxxxxxx>
---
Based on mm-nonmm-unstable
---
 fs/proc/inode.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 8de0af8c3..10a8481cc 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -474,12 +474,11 @@ static int proc_reg_open(struct inode *inode, struct file *file)
 	struct pde_opener *pdeo;
 
 	if (pde_is_permanent(pde)) {
+		if (!pde->proc_ops->proc_lseek)
+			file->f_mode &= ~FMODE_LSEEK;
 		open = pde->proc_ops->proc_open;
-		if (open) {
-			if (!pde->proc_ops->proc_lseek)
-				file->f_mode &= ~FMODE_LSEEK;
+		if (open)
 			rv = open(inode, file);
-		}
 		return rv;
 	}
 
-- 
2.25.1