From: ChenXiaoSong <chenxiaosong2@huawei.com> mainline inclusion from mainline-v5.18-rc2 commit ab0fc21bc7105b54bafd85bd8b82742f9e68898a category: bugfix bugzilla: 186890, https://gitee.com/openeuler/kernel/issues/I5BZTX CVE: NA -------------------------------- This reverts commit 44942b4e457beda00981f616402a1a791e8c616e. After secondly opening a file with O_ACCMODE|O_DIRECT flags, nfs4_valid_open_stateid() will dereference NULL nfs4_state when lseek(). Reproducer: 1. mount -t nfs -o vers=4.2 $server_ip:/ /mnt/ 2. fd = open("/mnt/file", O_ACCMODE|O_DIRECT|O_CREAT) 3. close(fd) 4. fd = open("/mnt/file", O_ACCMODE|O_DIRECT) 5. lseek(fd) Reported-by: Lyu Tao <tao.lyu@epfl.ch> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com> Reviewed-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- fs/nfs/inode.c | 1 - fs/nfs/nfs4file.c | 2 +- 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index db52430dfbd7..053e78d777f1 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1103,7 +1103,6 @@ int nfs_open(struct inode *inode, struct file *filp) nfs_fscache_open_file(inode, filp); return 0; } -EXPORT_SYMBOL_GPL(nfs_open); /* * This function is called whenever some part of NFS notices that diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c index e053a883d08d..09d65a654c2b 100644 --- a/fs/nfs/nfs4file.c +++ b/fs/nfs/nfs4file.c @@ -49,7 +49,7 @@ nfs4_file_open(struct inode *inode, struct file *filp) return err; if ((openflags & O_ACCMODE) == 3) - return nfs_open(inode, filp); + openflags--; /* We can't create new files here */ openflags &= ~(O_CREAT|O_EXCL); -- 2.25.1