lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Sat,  5 Dec 2020 21:09:04 +0800
From:   Chengguang Xu <cgxu519@...ernel.net>
To:     ericvh@...il.com, lucho@...kov.net, asmadeus@...ewreck.org
Cc:     v9fs-developer@...ts.sourceforge.net, linux-kernel@...r.kernel.org,
        Chengguang Xu <cgxu519@...ernel.net>
Subject: [RFC PATCH] 9p: create writeback fid on shared mmap

If vma is shared and the file was opened for writing,
we should also create writeback fid because vma may be
mprotected writable even if now readonly.

Signed-off-by: Chengguang Xu <cgxu519@...ernel.net>
---
Caveat: Only compile tested.

 fs/9p/vfs_file.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index b177fd3b1eb3..791839c2dd5c 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -516,8 +516,7 @@ v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
 	v9inode = V9FS_I(inode);
 	mutex_lock(&v9inode->v_mutex);
 	if (!v9inode->writeback_fid &&
-	    (vma->vm_flags & VM_SHARED) &&
-	    (vma->vm_flags & VM_WRITE)) {
+	    mapping_writably_mapped(filp->f_mapping)) {
 		/*
 		 * clone a fid and add it to writeback_fid
 		 * we do it during mmap instead of
-- 
2.26.2


Powered by blists - more mailing lists