On Mon, Jul 08, 2013 at 05:54:06PM +0200, Sven Geggus wrote:
> J. Bruce Fields schrieb am Montag, den 08. Juli um 15:35 Uhr:
>
> > Anyway. OK, that more or less solves the mystery, though the strace
> > output might still be interesting.
>
> Not very enlightening, at least for me, but here we go:
>
> read(3, "nfsd 10.1.7.30\n", 2048) = 15
> close(13) = 0
> open("/var/lib/nfs/etab", O_RDONLY) = 13
> close(13) = 0
> close(13) = 0
> write(3, "nfsd 10.1.7.30 1373300439 * \n", 29) = 29
> read(4, "4294967295\n", 2048) = 11
> close(14) = 0
> close(13) = 0
> read(13, "\2\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\377\377\377\377\377\377\377\377\0\0\0\0\0\0\0\0\0\0\0\0", 36) = 36
> close(13) = 0
> write(4, "4294967295 1373300439 0 \n", 25) = -1 EINVAL (Invalid argument)
Thanks! Yep, 4294967295 is (u32)(-1), so it's this uid_valid check in
unix_gid_parse that we're hitting.
I'm not even sure whether it makes sense to be doing this upcall to ask
for supplemental groups in the -1 case. Going with the minimal fix for
now.
Oh, and oops, it should go to stable to--adding that Cc: to my local
copy of the patch.
--b.
commit 8efb88340e29293e05f6b498b60596884c05a8a8
Author: J. Bruce Fields <bfields@xxxxxxxxxx>
Date: Mon Jul 8 13:44:45 2013 -0400
svcrpc: fix failures to handle -1 uid's
As of f025adf191924e3a75ce80e130afcd2485b53bb8 "sunrpc: Properly decode
kuids and kgids in RPC_AUTH_UNIX credentials" any rpc containing a -1
(0xffff) uid or gid would fail with a badcred error.
Commit afe3c3fd5392b2f0066930abc5dbd3f4b14a0f13 "svcrpc: fix failures to
handle -1 uid's and gid's" fixed part of the problem, but overlooked the
gid upcall--the kernel can request supplementary gid's for the -1 uid,
but mountd's attempt write a response will get -EINVAL.
Symptoms were nfsd failing to reply to the first attempt to use a newly
negotiated krb5 context.
Reported-by: Sven Geggus <lists@xxxxxxxxxxxxxxxxxxxxx>
Tested-by: Sven Geggus <lists@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index a98853d..621ca7b 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -493,8 +493,6 @@ static int unix_gid_parse(struct cache_detail *cd,
if (rv)
return -EINVAL;
uid = make_kuid(&init_user_ns, id);
- if (!uid_valid(uid))
- return -EINVAL;
ug.uid = uid;
expiry = get_expiry(&mesg);
--
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