iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

SUNRPC: fix sign error causing rpcsec_gss drops

Browse Source 
If sd_max is unsigned, then sd_max - GSS_SEQ_WIN is a very large number
whenever sd_max is less than GSS_SEQ_WIN, and the comparison:

	seq_num <= sd->sd_max - GSS_SEQ_WIN

in gss_check_seq_num is pretty much always true, even when that's
clearly not what was intended.

This was causing pynfs to hang when using krb5, because pynfs uses zero
as the initial gss sequence number.  That's perfectly legal, but this
logic error causes knfsd to drop the rpc in that case.  Out-of-order
sequence IDs in the first GSS_SEQ_WIN (128) calls will also cause this.

Fixes: 10b9d99a3dbb ("SUNRPC: Augment server-side rpcgss tracepoints")
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
This commit is contained in:
J. Bruce Fields 2021-10-01 09:59:21 -04:00 committed by Chuck Lever
parent 19598141f4
commit 2ba5acfb34
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
net/sunrpc/auth_gss/svcauth_gss.c
View File

@ -645,7 +645,7 @@ static bool gss_check_seq_num(const struct svc_rqst *rqstp, struct rsc *rsci,
}
__set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win);
goto ok;
} else if (seq_num <= sd->sd_max - GSS_SEQ_WIN) {
} else if (seq_num + GSS_SEQ_WIN <= sd->sd_max) {
goto toolow;
}
if (__test_and_set_bit(seq_num % GSS_SEQ_WIN, sd->sd_win))