Make sure that all variables are initialized and released in correct
order.
Reported-by: [email protected]
Signed-off-by: Leon Romanovsky <[email protected]>
---
net/9p/client.c | 37 ++++++++++++-------------------------
1 file changed, 12 insertions(+), 25 deletions(-)
diff --git a/net/9p/client.c b/net/9p/client.c
index aaa37b07e30a..8277e33506e7 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -179,7 +179,6 @@ static int parse_opts(char *opts, struct p9_client *clnt)
goto free_and_return;
}
- v9fs_put_trans(clnt->trans_mod);
clnt->trans_mod = v9fs_get_trans_by_name(s);
if (!clnt->trans_mod) {
pr_info("Could not find request transport: %s\n",
@@ -187,7 +186,7 @@ static int parse_opts(char *opts, struct p9_client *clnt)
ret = -EINVAL;
}
kfree(s);
- break;
+ goto free_and_return;
case Opt_legacy:
clnt->proto_version = p9_proto_legacy;
break;
@@ -211,9 +210,14 @@ static int parse_opts(char *opts, struct p9_client *clnt)
}
}
+ clnt->trans_mod = v9fs_get_default_trans();
+ if (!clnt->trans_mod) {
+ ret = -EPROTONOSUPPORT;
+ p9_debug(P9_DEBUG_ERROR,
+ "No transport defined or default transport\n");
+ }
+
free_and_return:
- if (ret)
- v9fs_put_trans(clnt->trans_mod);
kfree(tmp_options);
return ret;
}
@@ -956,19 +960,14 @@ static int p9_client_version(struct p9_client *c)
struct p9_client *p9_client_create(const char *dev_name, char *options)
{
- int err;
struct p9_client *clnt;
char *client_id;
+ int err = 0;
- err = 0;
- clnt = kmalloc(sizeof(*clnt), GFP_KERNEL);
+ clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
if (!clnt)
return ERR_PTR(-ENOMEM);
- clnt->trans_mod = NULL;
- clnt->trans = NULL;
- clnt->fcall_cache = NULL;
-
client_id = utsname()->nodename;
memcpy(clnt->name, client_id, strlen(client_id) + 1);
@@ -980,16 +979,6 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
if (err < 0)
goto free_client;
- if (!clnt->trans_mod)
- clnt->trans_mod = v9fs_get_default_trans();
-
- if (!clnt->trans_mod) {
- err = -EPROTONOSUPPORT;
- p9_debug(P9_DEBUG_ERROR,
- "No transport defined or default transport\n");
- goto free_client;
- }
-
p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
@@ -1044,9 +1033,8 @@ void p9_client_destroy(struct p9_client *clnt)
p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
- if (clnt->trans_mod)
- clnt->trans_mod->close(clnt);
-
+ kmem_cache_destroy(clnt->fcall_cache);
+ clnt->trans_mod->close(clnt);
v9fs_put_trans(clnt->trans_mod);
idr_for_each_entry(&clnt->fids, fid, id) {
@@ -1056,7 +1044,6 @@ void p9_client_destroy(struct p9_client *clnt)
p9_tag_cleanup(clnt);
- kmem_cache_destroy(clnt->fcall_cache);
kfree(clnt);
}
EXPORT_SYMBOL(p9_client_destroy);
--
2.37.3
Leon Romanovsky wrote on Thu, Sep 29, 2022 at 12:37:56PM +0300:
> Make sure that all variables are initialized and released in correct
> order.
Haven't tried running or compiling, comments out of my head that might
be wrong below
>
> Reported-by: [email protected]
You're adding this report tag but I don't see how you fix that failure.
What you need is p9_tag_cleanup(clnt) from p9_client_destroy -- I assume
this isn't possible for any fid to be allocated at this point so the fid
destroying loop is -probably- optional.
I would assume it is needed from p9_client_version failures.
> Signed-off-by: Leon Romanovsky <[email protected]>
> ---
> net/9p/client.c | 37 ++++++++++++-------------------------
> 1 file changed, 12 insertions(+), 25 deletions(-)
>
> diff --git a/net/9p/client.c b/net/9p/client.c
> index aaa37b07e30a..8277e33506e7 100644
> --- a/net/9p/client.c
> +++ b/net/9p/client.c
> @@ -179,7 +179,6 @@ static int parse_opts(char *opts, struct p9_client *clnt)
> goto free_and_return;
> }
>
> - v9fs_put_trans(clnt->trans_mod);
Pretty sure you'll be "leaking transports" if someone tries to pass
trans=foo multiple times; this can't be removed...(continues below)...
> clnt->trans_mod = v9fs_get_trans_by_name(s);
> if (!clnt->trans_mod) {
> pr_info("Could not find request transport: %s\n",
> @@ -187,7 +186,7 @@ static int parse_opts(char *opts, struct p9_client *clnt)
> ret = -EINVAL;
> }
> kfree(s);
> - break;
> + goto free_and_return;
... unless you also break the whole parsing, with this asking for -o
trans=virtio,msize=1M will just ignore the msize argument.
(or anything else that follows)
I appreciate that you're trying to avoid the get_default_trans below,
but unless you just remember the last string and try to get it get/put
trans is the most straight forward way to go.
(Note you just got me to try weird parsing and my old version was
double-puting these modules because of the put_trans below in this
function echoes with the client destroy. That'd just require removing
the put here though (or nulling after put), yet another invariant I had
wrongly assumed... Anyway.)
> case Opt_legacy:
> clnt->proto_version = p9_proto_legacy;
> break;
> @@ -211,9 +210,14 @@ static int parse_opts(char *opts, struct p9_client *clnt)
> }
> }
>
> + clnt->trans_mod = v9fs_get_default_trans();
> + if (!clnt->trans_mod) {
> + ret = -EPROTONOSUPPORT;
> + p9_debug(P9_DEBUG_ERROR,
> + "No transport defined or default transport\n");
> + }
> +
> free_and_return:
> - if (ret)
> - v9fs_put_trans(clnt->trans_mod);
(oh, and if you parse options after trans= you'll need some sort of
escape hatch here...)
> kfree(tmp_options);
> return ret;
> }
> @@ -956,19 +960,14 @@ static int p9_client_version(struct p9_client *c)
>
> struct p9_client *p9_client_create(const char *dev_name, char *options)
> {
> - int err;
> struct p9_client *clnt;
> char *client_id;
> + int err = 0;
>
> - err = 0;
> - clnt = kmalloc(sizeof(*clnt), GFP_KERNEL);
> + clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
> if (!clnt)
> return ERR_PTR(-ENOMEM);
>
> - clnt->trans_mod = NULL;
> - clnt->trans = NULL;
> - clnt->fcall_cache = NULL;
> -
> client_id = utsname()->nodename;
> memcpy(clnt->name, client_id, strlen(client_id) + 1);
>
> @@ -980,16 +979,6 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
> if (err < 0)
> goto free_client;
>
> - if (!clnt->trans_mod)
> - clnt->trans_mod = v9fs_get_default_trans();
> -
> - if (!clnt->trans_mod) {
> - err = -EPROTONOSUPPORT;
> - p9_debug(P9_DEBUG_ERROR,
> - "No transport defined or default transport\n");
> - goto free_client;
> - }
> -
> p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",
> clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);
>
> @@ -1044,9 +1033,8 @@ void p9_client_destroy(struct p9_client *clnt)
>
> p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
>
> - if (clnt->trans_mod)
> - clnt->trans_mod->close(clnt);
> -
> + kmem_cache_destroy(clnt->fcall_cache);
Pretty sure kmem_cache used to issue a warning when we did that (hence
me trying to move it up on allocation) -- at this point there can still
be in flight requests we need to finish freeing before we can destroy
the cache.
> + clnt->trans_mod->close(clnt);
> v9fs_put_trans(clnt->trans_mod);
>
> idr_for_each_entry(&clnt->fids, fid, id) {
> @@ -1056,7 +1044,6 @@ void p9_client_destroy(struct p9_client *clnt)
>
> p9_tag_cleanup(clnt);
>
> - kmem_cache_destroy(clnt->fcall_cache);
> kfree(clnt);
> }
> EXPORT_SYMBOL(p9_client_destroy);
--
Dominique
On Thu, Sep 29, 2022 at 07:29:33PM +0900, Dominique Martinet wrote:
> Leon Romanovsky wrote on Thu, Sep 29, 2022 at 12:37:56PM +0300:
> > Make sure that all variables are initialized and released in correct
> > order.
>
> Haven't tried running or compiling, comments out of my head that might
> be wrong below
>
> >
> > Reported-by: [email protected]
>
> You're adding this report tag but I don't see how you fix that failure.
> What you need is p9_tag_cleanup(clnt) from p9_client_destroy -- I assume
> this isn't possible for any fid to be allocated at this point so the fid
> destroying loop is -probably- optional.
>
> I would assume it is needed from p9_client_version failures.
>
>
> > Signed-off-by: Leon Romanovsky <[email protected]>
> > ---
> > net/9p/client.c | 37 ++++++++++++-------------------------
> > 1 file changed, 12 insertions(+), 25 deletions(-)
> >
> > diff --git a/net/9p/client.c b/net/9p/client.c
> > index aaa37b07e30a..8277e33506e7 100644
> > --- a/net/9p/client.c
> > +++ b/net/9p/client.c
> > @@ -179,7 +179,6 @@ static int parse_opts(char *opts, struct p9_client *clnt)
> > goto free_and_return;
> > }
> >
> > - v9fs_put_trans(clnt->trans_mod);
>
> Pretty sure you'll be "leaking transports" if someone tries to pass
> trans=foo multiple times; this can't be removed...(continues below)...
It is pity, you are right.
Thanks
On Donnerstag, 29. September 2022 12:53:27 CEST Leon Romanovsky wrote:
> On Thu, Sep 29, 2022 at 07:29:33PM +0900, Dominique Martinet wrote:
> > Leon Romanovsky wrote on Thu, Sep 29, 2022 at 12:37:56PM +0300:
> > > Make sure that all variables are initialized and released in correct
> > > order.
> >
> > Haven't tried running or compiling, comments out of my head that might
> > be wrong below
> >
> > > Reported-by: [email protected]
> >
> > You're adding this report tag but I don't see how you fix that failure.
> > What you need is p9_tag_cleanup(clnt) from p9_client_destroy -- I assume
> > this isn't possible for any fid to be allocated at this point so the fid
> > destroying loop is -probably- optional.
> >
> > I would assume it is needed from p9_client_version failures.
> >
> > > Signed-off-by: Leon Romanovsky <[email protected]>
> > > ---
> > >
> > > net/9p/client.c | 37 ++++++++++++-------------------------
> > > 1 file changed, 12 insertions(+), 25 deletions(-)
> > >
> > > diff --git a/net/9p/client.c b/net/9p/client.c
> > > index aaa37b07e30a..8277e33506e7 100644
> > > --- a/net/9p/client.c
> > > +++ b/net/9p/client.c
> > > @@ -179,7 +179,6 @@ static int parse_opts(char *opts, struct p9_client
> > > *clnt)> >
> > > goto free_and_return;
> > >
> > > }
> > >
> > > - v9fs_put_trans(clnt->trans_mod);
> >
> > Pretty sure you'll be "leaking transports" if someone tries to pass
> > trans=foo multiple times; this can't be removed...(continues below)...
>
> It is pity, you are right.
>
> Thanks
Hi Leon,
have you planned a v2 on this? Just asking, so that we know whether to go
forward.
Best regards,
Christian Schoenebeck