| Message ID | 20210531030550.1708816-1-yangyingliang@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [-next,v2] cifsd: check return value of ksmbd_vfs_getcasexattr() correctly | expand |
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? 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 >
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 >> > .
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; } 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; }
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(-)