From: ChenXiaoSong chenxiaosong2@huawei.com
stable inclusion from stable-v5.10.111 commit c688705a3978dd637389684bc5244927aeb8a67d category: bugfix bugzilla: 186205, https://gitee.com/openeuler/kernel/issues/I5BZTX CVE:NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit ab0fc21bc7105b54bafd85bd8b82742f9e68898a ]
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: Sasha Levin sashal@kernel.org Signed-off-by: ChenXiaoSong chenxiaosong2@huawei.com Reviewed-by: Zhang Xiaoxu zhangxiaoxu5@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@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 f27ecc2e490f..1adece1cff3e 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1139,7 +1139,6 @@ 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 079ec1947c24..1fe2f612c5c9 100644 --- a/fs/nfs/nfs4file.c +++ b/fs/nfs/nfs4file.c @@ -51,7 +51,7 @@ 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);