[SSSD] [PATCH] PAM: close socket fd with pam_set_data
Jakub Hrozek
jhrozek at redhat.com
Thu Oct 11 18:23:19 UTC 2012
On Thu, Oct 11, 2012 at 09:30:29AM -0400, Simo Sorce wrote:
> On Thu, 2012-10-11 at 10:00 +0200, Jakub Hrozek wrote:
> > From 98c8a6b92db2872083473b4ce0761bffc919e847 Mon Sep 17 00:00:00 2001
> > From: Jakub Hrozek <jhrozek at redhat.com>
> > Date: Thu, 4 Oct 2012 19:08:08 +0200
> > Subject: [PATCH] PAM: close socket fd with pam_set_data
> >
> > https://fedorahosted.org/sssd/ticket/1569
> > ---
> > src/sss_client/common.c | 6 ++++++
> > src/sss_client/pam_sss.c | 26 ++++++++++++++++++++++++++
> > src/sss_client/sss_cli.h | 2 ++
> > 3 files changed, 34 insertions(+)
> >
> > diff --git a/src/sss_client/common.c b/src/sss_client/common.c
> > index
> > 1ef3ba15e5a86952a05de29c9db212fc829111bc..a4d523cdf45665c2e1b4984cc9b6db14c3d05340 100644
> > --- a/src/sss_client/common.c
> > +++ b/src/sss_client/common.c
> > @@ -794,6 +794,12 @@ errno_t check_server_cred(int sockfd)
> > #endif
> > return 0;
> > }
> > +
> > +int *sss_pam_get_socket(void)
> > +{
> > + return &sss_cli_sd;
> > +}
> > +
> > int sss_pam_make_request(enum sss_cli_command cmd,
> > struct sss_cli_req_data *rd,
> > uint8_t **repbuf, size_t *replen,
> > diff --git a/src/sss_client/pam_sss.c b/src/sss_client/pam_sss.c
> > index
> > efbc48b6ef0458bb79dad53f81c584611f2be22d..92c90742e1931cf063a769a13befa8ec3567969a 100644
> > --- a/src/sss_client/pam_sss.c
> > +++ b/src/sss_client/pam_sss.c
> > @@ -54,6 +54,7 @@
> > #define FLAGS_USE_AUTHTOK (1 << 2)
> >
> > #define PWEXP_FLAG "pam_sss:password_expired_flag"
> > +#define FD_DESTRUCTOR "pam_sss:fd_destructor"
> >
> > #define PW_RESET_MSG_FILENAME_TEMPLATE SSSD_CONF_DIR"/customize/%
> > s/pam_sss_pw_reset_message.%s"
> > #define PW_RESET_MSG_MAX_SIZE 4096
> > @@ -122,6 +123,24 @@ static void free_exp_data(pam_handle_t *pamh,
> > void *ptr, int err)
> > ptr = NULL;
> > }
> >
> > +static void close_fd(pam_handle_t *pamh, void *ptr, int err)
> > +{
> > + int fd = *((int *) ptr);
> > +
> > + if (err & PAM_DATA_REPLACE) {
> > + /* Nothing to do */
> > + return;
> > + }
> > +
> > + if (fd == -1) {
> > + /* fd not yet initialized */
> > + return;
> > + }
> > +
> > + D(("Closing the fd"));
> > + close(fd);
> > +}
>
> NACK, ^^^^^^^^^
I'm sorry Simo but your Nack came too late after I pushed the patch and
before I sent a pushmail, so I'll attach a fix.
As discussed off-list already I will CC you with any future client
patches.
> you are closing the fd and leaving sss_cli_sd untouched, which means it
> will still point to a random file descriptor.
>
fixed
> Also I do not understand why this whole dance in passing pointers and
> the sss_pam_get_socket() function, seem all very unnecessary.
> .
> sss_cli_sd is a global variable which means:
> a) you can access it directly
Yes and no, it's local to the sss_client/common.c module, so I moved
closing the socket there.
> b) you need mutexes to access it (see sss_pam_make_request()).
fixed
The attached fix should amend the code as you suggested.
-------------- next part --------------
>From 83593a2d3452faeb59acc229d5c102ab58b8f76e Mon Sep 17 00:00:00 2001
From: Jakub Hrozek <jhrozek at redhat.com>
Date: Thu, 11 Oct 2012 20:18:18 +0200
Subject: [PATCH] PAM: fix handling the client fd in pam destructor
* Protect the fd with a mutex when closing
* Set it to a safe value after closing
---
src/sss_client/common.c | 17 ++++++++++++-----
src/sss_client/pam_sss.c | 11 ++---------
src/sss_client/sss_cli.h | 8 ++++----
3 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/src/sss_client/common.c b/src/sss_client/common.c
index a4d523cdf45665c2e1b4984cc9b6db14c3d05340..7cfa3e0ef58e91315100e7571dff60c3bd21e9d9 100644
--- a/src/sss_client/common.c
+++ b/src/sss_client/common.c
@@ -795,11 +795,6 @@ errno_t check_server_cred(int sockfd)
return 0;
}
-int *sss_pam_get_socket(void)
-{
- return &sss_cli_sd;
-}
-
int sss_pam_make_request(enum sss_cli_command cmd,
struct sss_cli_req_data *rd,
uint8_t **repbuf, size_t *replen,
@@ -879,6 +874,18 @@ out:
return ret;
}
+void sss_pam_close_fd(void)
+{
+ sss_pam_lock();
+
+ if (sss_cli_sd != -1) {
+ close(sss_cli_sd);
+ sss_cli_sd = -1;
+ }
+
+ sss_pam_unlock();
+}
+
int sss_sudo_make_request(enum sss_cli_command cmd,
struct sss_cli_req_data *rd,
uint8_t **repbuf, size_t *replen,
diff --git a/src/sss_client/pam_sss.c b/src/sss_client/pam_sss.c
index 90d4c0a331f4bac81426d148e529b41060b19250..3734c8f083cc3093dfb15f15d5af3096df631678 100644
--- a/src/sss_client/pam_sss.c
+++ b/src/sss_client/pam_sss.c
@@ -125,20 +125,13 @@ static void free_exp_data(pam_handle_t *pamh, void *ptr, int err)
static void close_fd(pam_handle_t *pamh, void *ptr, int err)
{
- int fd = *((int *) ptr);
-
if (err & PAM_DATA_REPLACE) {
/* Nothing to do */
return;
}
- if (fd == -1) {
- /* fd not yet initialized */
- return;
- }
-
D(("Closing the fd"));
- close(fd);
+ sss_pam_close_fd();
}
static size_t add_authtok_item(enum pam_item_type type,
@@ -1098,7 +1091,7 @@ static int send_and_receive(pam_handle_t *pamh, struct pam_items *pi,
errnop = 0;
ret = sss_pam_make_request(task, &rd, &repbuf, &replen, &errnop);
- sret = pam_set_data(pamh, FD_DESTRUCTOR, sss_pam_get_socket(), close_fd);
+ sret = pam_set_data(pamh, FD_DESTRUCTOR, NULL, close_fd);
if (sret != PAM_SUCCESS) {
D(("pam_set_data failed, client might leaks fds"));
}
diff --git a/src/sss_client/sss_cli.h b/src/sss_client/sss_cli.h
index f3cb44adbcefb31c60c88c71e9251b351dc3a6c7..372bcee596a72e85d02516acdb10b775c4ddc2df 100644
--- a/src/sss_client/sss_cli.h
+++ b/src/sss_client/sss_cli.h
@@ -478,10 +478,10 @@ enum nss_status sss_nss_make_request(enum sss_cli_command cmd,
int *errnop);
int sss_pam_make_request(enum sss_cli_command cmd,
- struct sss_cli_req_data *rd,
- uint8_t **repbuf, size_t *replen,
- int *errnop);
-int *sss_pam_get_socket(void);
+ struct sss_cli_req_data *rd,
+ uint8_t **repbuf, size_t *replen,
+ int *errnop);
+void sss_pam_close_fd(void);
int sss_pac_make_request(enum sss_cli_command cmd,
struct sss_cli_req_data *rd,
--
1.7.11.4
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