From c87a37ebd40b889178664c2c09cc187334146292 Mon Sep 17 00:00:00 2001 From: Chengguang Xu Date: Tue, 20 Aug 2019 18:03:25 +0800 Subject: 9p: avoid attaching writeback_fid on mmap with type PRIVATE Currently on mmap cache policy, we always attach writeback_fid whether mmap type is SHARED or PRIVATE. However, in the use case of kata-container which combines 9p(Guest OS) with overlayfs(Host OS), this behavior will trigger overlayfs' copy-up when excute command inside container. Link: http://lkml.kernel.org/r/20190820100325.10313-1-cgxu519@zoho.com.cn Signed-off-by: Chengguang Xu Signed-off-by: Dominique Martinet --- fs/9p/vfs_file.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/9p') diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 4cc966a31cb3..fe7f0bd2048e 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -513,6 +513,7 @@ 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)) { /* * clone a fid and add it to writeback_fid @@ -614,6 +615,8 @@ static void v9fs_mmap_vm_close(struct vm_area_struct *vma) (vma->vm_end - vma->vm_start - 1), }; + if (!(vma->vm_flags & VM_SHARED)) + return; p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma); -- cgit v1.2.3 From 962a991c5de18452d6c429d99f3039387cf5cbb0 Mon Sep 17 00:00:00 2001 From: Bharath Vedartham Date: Thu, 23 May 2019 01:15:19 +0530 Subject: 9p/cache.c: Fix memory leak in v9fs_cache_session_get_cookie v9fs_cache_session_get_cookie assigns a random cachetag to v9ses->cachetag, if the cachetag is not assigned previously. v9fs_random_cachetag allocates memory to v9ses->cachetag with kmalloc and uses scnprintf to fill it up with a cachetag. But if scnprintf fails, v9ses->cachetag is not freed in the current code causing a memory leak. Fix this by freeing v9ses->cachetag it v9fs_random_cachetag fails. This was reported by syzbot, the link to the report is below: https://syzkaller.appspot.com/bug?id=f012bdf297a7a4c860c38a88b44fbee43fd9bbf3 Link: http://lkml.kernel.org/r/20190522194519.GA5313@bharath12345-Inspiron-5559 Reported-by: syzbot+3a030a73b6c1e9833815@syzkaller.appspotmail.com Signed-off-by: Bharath Vedartham Signed-off-by: Dominique Martinet --- fs/9p/cache.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/9p') diff --git a/fs/9p/cache.c b/fs/9p/cache.c index 995e332eee5c..eb2151fb6049 100644 --- a/fs/9p/cache.c +++ b/fs/9p/cache.c @@ -51,6 +51,8 @@ void v9fs_cache_session_get_cookie(struct v9fs_session_info *v9ses) if (!v9ses->cachetag) { if (v9fs_random_cachetag(v9ses) < 0) { v9ses->fscache = NULL; + kfree(v9ses->cachetag); + v9ses->cachetag = NULL; return; } } -- cgit v1.2.3 From aafee43b72863f1f70aeaf1332d049916e8df239 Mon Sep 17 00:00:00 2001 From: Bharath Vedartham Date: Thu, 23 May 2019 22:26:20 +0530 Subject: 9p/vfs_super.c: Remove unused parameter data in v9fs_fill_super v9fs_fill_super has a param 'void *data' which is unused in the function. This patch removes the 'void *data' param in v9fs_fill_super and changes the parameters in all function calls of v9fs_fill_super. Link: http://lkml.kernel.org/r/20190523165619.GA4209@bharath12345-Inspiron-5559 Signed-off-by: Bharath Vedartham Signed-off-by: Dominique Martinet --- fs/9p/vfs_super.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/9p') diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 08112fbcaece..6c5ac0a5e539 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -58,7 +58,7 @@ static int v9fs_set_super(struct super_block *s, void *data) static int v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, - int flags, void *data) + int flags) { int ret; @@ -128,7 +128,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, retval = PTR_ERR(sb); goto clunk_fid; } - retval = v9fs_fill_super(sb, v9ses, flags, data); + retval = v9fs_fill_super(sb, v9ses, flags); if (retval) goto release_sb; -- cgit v1.2.3