knfsd: fix resource leak resulting in module refcount leak for rpcsec_gss_krb5.ko
I have been investigating a module reference count leak on the server for rpcsec_gss_krb5.ko. It turns out the problem is a reference count leak for the security context in net/sunrpc/auth_gss/svcauth_gss.c. The problem is that gss_write_init_verf() calls gss_svc_searchbyctx() which does a rsc_lookup() but never releases the reference to the context. There is another issue that rpc.svcgssd sets an "end of time" expiration for the context By adding a cache_put() call in gss_svc_searchbyctx(), and setting an expiration timeout in the downcall, cache_clean() does clean up the context and the module reference count now goes to zero after unmount. I also verified that if the context expires and then the client makes a new request, a new context is established. Here is the patch to fix the kernel, I will start a separate thread to discuss what expiration time should be set by rpc.svcgssd. Acked-by: "J. Bruce Fields" <bfields@citi.umich.edu> Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
153e44d22f
commit
54f9247b3f
|
@ -924,6 +924,7 @@ static inline int
|
|||
gss_write_init_verf(struct svc_rqst *rqstp, struct rsi *rsip)
|
||||
{
|
||||
struct rsc *rsci;
|
||||
int rc;
|
||||
|
||||
if (rsip->major_status != GSS_S_COMPLETE)
|
||||
return gss_write_null_verf(rqstp);
|
||||
|
@ -932,7 +933,9 @@ gss_write_init_verf(struct svc_rqst *rqstp, struct rsi *rsip)
|
|||
rsip->major_status = GSS_S_NO_CONTEXT;
|
||||
return gss_write_null_verf(rqstp);
|
||||
}
|
||||
return gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
|
||||
rc = gss_write_verf(rqstp, rsci->mechctx, GSS_SEQ_WIN);
|
||||
cache_put(&rsci->h, &rsc_cache);
|
||||
return rc;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
Loading…
Reference in New Issue