On 2021/5/31 13:38, Hyunchul Lee wrote:
2021년 5월 31일 (월) 오후 12:01, Yang Yingliang <yangyingliang@xxxxxxxxxx>님이 작성:If ksmbd_vfs_getcasexattr() returns -ENOMEM, stream_buf is NULL, it will cause null-ptr-deref when using it to copy memory. So we need check the return value of ksmbd_vfs_getcasexattr() by comparing with 0. Fixes: f44158485826 ("cifsd: add file operations") Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> --- v2: Handle the case ksmbd_vfs_getcasexattr() returns 0. --- fs/cifsd/vfs.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/fs/cifsd/vfs.c b/fs/cifsd/vfs.c index 97d5584ec870..2a9cc0bc7726 100644 --- a/fs/cifsd/vfs.c +++ b/fs/cifsd/vfs.c @@ -274,7 +274,6 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos, { ssize_t v_len; char *stream_buf = NULL; - int err; ksmbd_debug(VFS, "read stream data pos : %llu, count : %zd\n", *pos, count); @@ -283,10 +282,9 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos, fp->stream.name, fp->stream.size, &stream_buf); - if (v_len == -ENOENT) { + if ((int)v_len <= 0) { ksmbd_err("not found stream in xattr : %zd\n", v_len); - err = -ENOENT; - return err; + return v_len == 0 ? -ENOENT : (int)v_len;How about making ksmbd_vfs_getcasexattr return -ENONENT instead of returning 0 to remove duplicate error handling code?
Yes, I think it's ok, I will send a v3 later. Thanks, Yang
Thanks, Hyunchul} memcpy(buf, &stream_buf[*pos], count); @@ -415,9 +413,9 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos, fp->stream.name, fp->stream.size, &stream_buf); - if (v_len == -ENOENT) { + if ((int)v_len <= 0) { ksmbd_err("not found stream in xattr : %zd\n", v_len); - err = -ENOENT; + err = v_len == 0 ? -ENOENT : (int)v_len; goto out; } -- 2.25.1.
