| Message ID | 20210529082058.3012233-3-yangyingliang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [-next,1/3] cifsd: fix memleak in ksmbd_vfs_stream_write() | expand |
Hi Yang, 2021년 5월 29일 (토) 오후 5:16, Yang Yingliang <yangyingliang@huawei.com>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@huawei.com> > --- > 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..45ba30f1f2d2 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) { because ksmbd_vfs_getcasexattr can return 0, 0 has to be handled. Thanks, Hyunchul > ksmbd_err("not found stream in xattr : %zd\n", v_len); > - err = -ENOENT; > - return err; > + return (int)v_len; > } > > 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 = (int)v_len; > goto out; > } > > -- > 2.25.1 >
diff --git a/fs/cifsd/vfs.c b/fs/cifsd/vfs.c index 97d5584ec870..45ba30f1f2d2 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 (int)v_len; } 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 = (int)v_len; goto out; }
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@huawei.com> --- fs/cifsd/vfs.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)