Messages in this thread | | | Subject | Re: [PATCH -next v2] cifsd: check return value of ksmbd_vfs_getcasexattr() correctly | From | Yang Yingliang <> | Date | Mon, 31 May 2021 14:09:40 +0800 |
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On 2021/5/31 13:38, Hyunchul Lee wrote: > 2021년 5월 31일 (월) 오후 12:01, 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> >> --- >> 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 >> > .
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