Re: [stable] [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Tue, Oct 09, 2007 at 11:27:57AM -0400, Trond Myklebust wrote: > > Please see the attachment. Thanks, I've applied this to the tree. greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Tue, 2007-10-09 at 08:13 -0700, Greg KH wrote:
> On Tue, Oct 09, 2007 at 11:00:28AM -0400, Trond Myklebust wrote:
> >
> > On Mon, 2007-10-08 at 22:01 +0200, Roel Kluin wrote:
> > > Greg KH wrote:
> > >
> > > @@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
> > >
> > > if (block == NULL) {
> > > struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
> > > + struct nlm_host *host;
> > >
> > > if (conf == NULL)
> > > return nlm_granted;
> > > - block = nlmsvc_create_block(rqstp, file, lock, cookie);
> > > + /* Create host handle for callback */
> > > + host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
> > > + if (host == NULL)
> > > + return nlm_lck_denied_nolocks;
> > > + block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
> > > if (block == NULL) {
> > > kfree(conf);
> > > return nlm_granted;
> > >
> > > To be frankly I don't know what this is about, but shouldn't conf be
> > > freed if host == NULL?
> >
> > Thanks for spotting this!
> >
> > Greg, should I resend this patch, or would you prefer an incremental
> > fix?
>
> An incremental one would be best.
>
> thanks,
>
> greg k-h
Please see the attachment.
Cheers
Trond
--- Begin Message ---
The recent fix for a circular lock dependency unfortunately introduced a
potential memory leak in the event where the call to nlmsvc_lookup_host
fails for some reason.
Thanks to Roel Kluin for spotting this.
Signed-off-by: Trond Myklebust <[EMAIL PROTECTED]>
---
fs/lockd/svclock.c |4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index d098c7a..d120ec3 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -485,8 +485,10 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file
*file,
return nlm_granted;
/* Create host handle for callback */
host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
- if (host == NULL)
+ if (host == NULL) {
+ kfree(conf);
return nlm_lck_denied_nolocks;
+ }
block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
--- End Message ---
Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Tue, Oct 09, 2007 at 11:00:28AM -0400, Trond Myklebust wrote:
>
> On Mon, 2007-10-08 at 22:01 +0200, Roel Kluin wrote:
> > Greg KH wrote:
> >
> > @@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
> >
> > if (block == NULL) {
> > struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
> > + struct nlm_host *host;
> >
> > if (conf == NULL)
> > return nlm_granted;
> > - block = nlmsvc_create_block(rqstp, file, lock, cookie);
> > + /* Create host handle for callback */
> > + host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
> > + if (host == NULL)
> > + return nlm_lck_denied_nolocks;
> > + block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
> > if (block == NULL) {
> > kfree(conf);
> > return nlm_granted;
> >
> > To be frankly I don't know what this is about, but shouldn't conf be freed
> > if host == NULL?
>
> Thanks for spotting this!
>
> Greg, should I resend this patch, or would you prefer an incremental
> fix?
An incremental one would be best.
thanks,
greg k-h
-
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Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Mon, 2007-10-08 at 22:01 +0200, Roel Kluin wrote:
> Greg KH wrote:
>
> @@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
>
> if (block == NULL) {
> struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
> + struct nlm_host *host;
>
> if (conf == NULL)
> return nlm_granted;
> - block = nlmsvc_create_block(rqstp, file, lock, cookie);
> + /* Create host handle for callback */
> + host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
> + if (host == NULL)
> + return nlm_lck_denied_nolocks;
> + block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
> if (block == NULL) {
> kfree(conf);
> return nlm_granted;
>
> To be frankly I don't know what this is about, but shouldn't conf be freed if
> host == NULL?
Thanks for spotting this!
Greg, should I resend this patch, or would you prefer an incremental
fix?
Cheers
Trond
-
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Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Mon, 2007-10-08 at 22:01 +0200, Roel Kluin wrote:
Greg KH wrote:
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
To be frankly I don't know what this is about, but shouldn't conf be freed if
host == NULL?
Thanks for spotting this!
Greg, should I resend this patch, or would you prefer an incremental
fix?
Cheers
Trond
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Tue, Oct 09, 2007 at 11:00:28AM -0400, Trond Myklebust wrote:
On Mon, 2007-10-08 at 22:01 +0200, Roel Kluin wrote:
Greg KH wrote:
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
To be frankly I don't know what this is about, but shouldn't conf be freed
if host == NULL?
Thanks for spotting this!
Greg, should I resend this patch, or would you prefer an incremental
fix?
An incremental one would be best.
thanks,
greg k-h
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Tue, 2007-10-09 at 08:13 -0700, Greg KH wrote:
On Tue, Oct 09, 2007 at 11:00:28AM -0400, Trond Myklebust wrote:
On Mon, 2007-10-08 at 22:01 +0200, Roel Kluin wrote:
Greg KH wrote:
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
To be frankly I don't know what this is about, but shouldn't conf be
freed if host == NULL?
Thanks for spotting this!
Greg, should I resend this patch, or would you prefer an incremental
fix?
An incremental one would be best.
thanks,
greg k-h
Please see the attachment.
Cheers
Trond
---BeginMessage---
The recent fix for a circular lock dependency unfortunately introduced a
potential memory leak in the event where the call to nlmsvc_lookup_host
fails for some reason.
Thanks to Roel Kluin for spotting this.
Signed-off-by: Trond Myklebust [EMAIL PROTECTED]
---
fs/lockd/svclock.c |4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index d098c7a..d120ec3 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -485,8 +485,10 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file
*file,
return nlm_granted;
/* Create host handle for callback */
host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
- if (host == NULL)
+ if (host == NULL) {
+ kfree(conf);
return nlm_lck_denied_nolocks;
+ }
block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
---End Message---
Re: [stable] [patch 08/12] NLM: Fix a circular lock dependency in lockd
On Tue, Oct 09, 2007 at 11:27:57AM -0400, Trond Myklebust wrote: Please see the attachment. Thanks, I've applied this to the tree. greg k-h - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
Greg KH wrote:
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
To be frankly I don't know what this is about, but shouldn't conf be freed if
host == NULL?
-
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the body of a message to [EMAIL PROTECTED]
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Please read the FAQ at http://www.tux.org/lkml/
[patch 08/12] NLM: Fix a circular lock dependency in lockd
From: Trond Myklebust <[EMAIL PROTECTED]>
commit 255129d1e9ca0ed3d69d5517fae3e03d7ab4b806 in upstream.
The problem is that the garbage collector for the 'host' structures
nlm_gc_hosts(), holds nlm_host_mutex while calling down to
nlmsvc_mark_resources, which, eventually takes the file->f_mutex.
We cannot therefore call nlmsvc_lookup_host() from within
nlmsvc_create_block, since the caller will already hold file->f_mutex, so
the attempt to grab nlm_host_mutex may deadlock.
Fix the problem by calling nlmsvc_lookup_host() outside the file->f_mutex.
Signed-off-by: Trond Myklebust <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
fs/lockd/svclock.c | 29 ++---
1 file changed, 18 insertions(+), 11 deletions(-)
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -171,19 +171,14 @@ found:
* GRANTED_RES message by cookie, without having to rely on the client's IP
* address. --okir
*/
-static inline struct nlm_block *
-nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
- struct nlm_lock *lock, struct nlm_cookie *cookie)
+static struct nlm_block *
+nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
+ struct nlm_file *file, struct nlm_lock *lock,
+ struct nlm_cookie *cookie)
{
struct nlm_block*block;
- struct nlm_host *host;
struct nlm_rqst *call = NULL;
- /* Create host handle for callback */
- host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
- if (host == NULL)
- return NULL;
-
call = nlm_alloc_call(host);
if (call == NULL)
return NULL;
@@ -366,6 +361,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
struct nlm_lock *lock, int wait, struct nlm_cookie
*cookie)
{
struct nlm_block*block = NULL;
+ struct nlm_host *host;
int error;
__be32 ret;
@@ -377,6 +373,10 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
(long long)lock->fl.fl_end,
wait);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
/* Lock file against concurrent access */
mutex_lock(>f_mutex);
@@ -385,7 +385,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
*/
block = nlmsvc_lookup_block(file, lock);
if (block == NULL) {
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ block = nlmsvc_create_block(rqstp, nlm_get_host(host), file,
+ lock, cookie);
ret = nlm_lck_denied_nolocks;
if (block == NULL)
goto out;
@@ -449,6 +450,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
out:
mutex_unlock(>f_mutex);
nlmsvc_release_block(block);
+ nlm_release_host(host);
dprintk("lockd: nlmsvc_lock returned %u\n", ret);
return ret;
}
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
--
-
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[patch 08/12] NLM: Fix a circular lock dependency in lockd
From: Trond Myklebust [EMAIL PROTECTED]
commit 255129d1e9ca0ed3d69d5517fae3e03d7ab4b806 in upstream.
The problem is that the garbage collector for the 'host' structures
nlm_gc_hosts(), holds nlm_host_mutex while calling down to
nlmsvc_mark_resources, which, eventually takes the file-f_mutex.
We cannot therefore call nlmsvc_lookup_host() from within
nlmsvc_create_block, since the caller will already hold file-f_mutex, so
the attempt to grab nlm_host_mutex may deadlock.
Fix the problem by calling nlmsvc_lookup_host() outside the file-f_mutex.
Signed-off-by: Trond Myklebust [EMAIL PROTECTED]
Signed-off-by: Linus Torvalds [EMAIL PROTECTED]
Signed-off-by: Greg Kroah-Hartman [EMAIL PROTECTED]
---
fs/lockd/svclock.c | 29 ++---
1 file changed, 18 insertions(+), 11 deletions(-)
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -171,19 +171,14 @@ found:
* GRANTED_RES message by cookie, without having to rely on the client's IP
* address. --okir
*/
-static inline struct nlm_block *
-nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
- struct nlm_lock *lock, struct nlm_cookie *cookie)
+static struct nlm_block *
+nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
+ struct nlm_file *file, struct nlm_lock *lock,
+ struct nlm_cookie *cookie)
{
struct nlm_block*block;
- struct nlm_host *host;
struct nlm_rqst *call = NULL;
- /* Create host handle for callback */
- host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
- if (host == NULL)
- return NULL;
-
call = nlm_alloc_call(host);
if (call == NULL)
return NULL;
@@ -366,6 +361,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
struct nlm_lock *lock, int wait, struct nlm_cookie
*cookie)
{
struct nlm_block*block = NULL;
+ struct nlm_host *host;
int error;
__be32 ret;
@@ -377,6 +373,10 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
(long long)lock-fl.fl_end,
wait);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
/* Lock file against concurrent access */
mutex_lock(file-f_mutex);
@@ -385,7 +385,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
*/
block = nlmsvc_lookup_block(file, lock);
if (block == NULL) {
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ block = nlmsvc_create_block(rqstp, nlm_get_host(host), file,
+ lock, cookie);
ret = nlm_lck_denied_nolocks;
if (block == NULL)
goto out;
@@ -449,6 +450,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
out:
mutex_unlock(file-f_mutex);
nlmsvc_release_block(block);
+ nlm_release_host(host);
dprintk(lockd: nlmsvc_lock returned %u\n, ret);
return ret;
}
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
--
-
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Re: [patch 08/12] NLM: Fix a circular lock dependency in lockd
Greg KH wrote:
@@ -477,10 +479,15 @@ nlmsvc_testlock(struct svc_rqst *rqstp,
if (block == NULL) {
struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ struct nlm_host *host;
if (conf == NULL)
return nlm_granted;
- block = nlmsvc_create_block(rqstp, file, lock, cookie);
+ /* Create host handle for callback */
+ host = nlmsvc_lookup_host(rqstp, lock-caller, lock-len);
+ if (host == NULL)
+ return nlm_lck_denied_nolocks;
+ block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
if (block == NULL) {
kfree(conf);
return nlm_granted;
To be frankly I don't know what this is about, but shouldn't conf be freed if
host == NULL?
-
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the body of a message to [EMAIL PROTECTED]
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Please read the FAQ at http://www.tux.org/lkml/
