| Message ID | 20210423151919.195033-1-ckuehl@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fuse: Send FUSE_WRITE_KILL_SUIDGID for killpriv v1 | expand |
On Fri, 23 Apr 2021 at 17:19, Connor Kuehl <ckuehl@redhat.com> wrote: > > FUSE doesn't seem to be adding the FUSE_WRITE_KILL_SUIDGID flag on write > requests for FUSE connections that support FUSE_HANDLE_KILLPRIV but not > FUSE_HANDLE_KILLPRIV_V2. > > However, the FUSE userspace header states: > > FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on > write/chown/trunc > ^^^^^ > > To improve backwards compatibility with file servers that don't support > FUSE_HANDLE_KILLPRIV_V2, add the FUSE_WRITE_KILL_SUIDGID flag to write > requests if FUSE_HANDLE_KILLPRIV has been negotiated -OR- if the > conditions for FUSE_HANDLE_KILLPRIV_V2 support are met. If server does not support FUSE_HANDLE_KILLPRIV_V2, then it does not support FUSE_WRITE_KILL_SUIDGID either. The two were introduced together and the latter is only meaningful if the FUSE_HANDLE_KILLPRIV_V2 feature was negotiated. What am I missing? Thanks, Miklos
On 6/21/21 3:26 AM, Miklos Szeredi wrote: > On Fri, 23 Apr 2021 at 17:19, Connor Kuehl <ckuehl@redhat.com> wrote: >> >> FUSE doesn't seem to be adding the FUSE_WRITE_KILL_SUIDGID flag on write >> requests for FUSE connections that support FUSE_HANDLE_KILLPRIV but not >> FUSE_HANDLE_KILLPRIV_V2. >> >> However, the FUSE userspace header states: >> >> FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on >> write/chown/trunc >> ^^^^^ >> >> To improve backwards compatibility with file servers that don't support >> FUSE_HANDLE_KILLPRIV_V2, add the FUSE_WRITE_KILL_SUIDGID flag to write >> requests if FUSE_HANDLE_KILLPRIV has been negotiated -OR- if the >> conditions for FUSE_HANDLE_KILLPRIV_V2 support are met. > > > If server does not support FUSE_HANDLE_KILLPRIV_V2, then it does not > support FUSE_WRITE_KILL_SUIDGID either. The two were introduced > together and the latter is only meaningful if the > FUSE_HANDLE_KILLPRIV_V2 feature was negotiated. > > What am I missing? You're not missing anything, this patch is wrong. Let's nack this. Thanks! Connor
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 8cccecb55fb8..7dc9182d1ece 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1106,7 +1106,7 @@ static ssize_t fuse_send_write_pages(struct fuse_io_args *ia, fuse_write_args_fill(ia, ff, pos, count); ia->write.in.flags = fuse_write_flags(iocb); - if (fm->fc->handle_killpriv_v2 && !capable(CAP_FSETID)) + if (fm->fc->handle_killpriv || (fm->fc->handle_killpriv_v2 && !capable(CAP_FSETID))) ia->write.in.write_flags |= FUSE_WRITE_KILL_SUIDGID; err = fuse_simple_request(fm, &ap->args);
FUSE doesn't seem to be adding the FUSE_WRITE_KILL_SUIDGID flag on write requests for FUSE connections that support FUSE_HANDLE_KILLPRIV but not FUSE_HANDLE_KILLPRIV_V2. However, the FUSE userspace header states: FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc ^^^^^ To improve backwards compatibility with file servers that don't support FUSE_HANDLE_KILLPRIV_V2, add the FUSE_WRITE_KILL_SUIDGID flag to write requests if FUSE_HANDLE_KILLPRIV has been negotiated -OR- if the conditions for FUSE_HANDLE_KILLPRIV_V2 support are met. Signed-off-by: Connor Kuehl <ckuehl@redhat.com> --- fs/fuse/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)