+ proc-clear-fmode_lseek-flag-correctly-for-permanent-pde.patch added to mm-nonmm-unstable branch

+ proc-clear-fmode_lseek-flag-correctly-for-permanent-pde.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: proc: clear FMODE_LSEEK flag correctly for permanent pde
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     proc-clear-fmode_lseek-flag-correctly-for-permanent-pde.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/proc-clear-fmode_lseek-flag-correctly-for-permanent-pde.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: wangzijie <wangzijie1@honor.com>
Subject: proc: clear FMODE_LSEEK flag correctly for permanent pde
Date: Thu, 5 Jun 2025 14:52:52 +0800

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

Link: https://lkml.kernel.org/r/20250605065252.900317-1-wangzijie1@honor.com
Fixes: ad7f4ea6e36e ("proc: avoid use-after-free in proc_reg_open()")
Signed-off-by: wangzijie <wangzijie1@honor.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/inode.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/fs/proc/inode.c~proc-clear-fmode_lseek-flag-correctly-for-permanent-pde
+++ a/fs/proc/inode.c
@@ -474,12 +474,11 @@ static int proc_reg_open(struct inode *i
 	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;
 	}
 
_

Patches currently in -mm which might be from wangzijie1@honor.com are

proc-avoid-use-after-free-in-proc_reg_open.patch
proc-clear-fmode_lseek-flag-correctly-for-permanent-pde.patch