diff options
| author | piaojun <piaojun@huawei.com> | 2018-07-13 16:59:06 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-24 13:07:10 +0200 |
| commit | 41b5285e24173c0d20aab129111acccff9dbcb9f (patch) | |
| tree | 95635c5cd22768671bf92d3bd5ee26230c09708d | |
| parent | 4a6a2cba9276854f985d977fea149051d2e9ab4b (diff) | |
net/9p/client.c: put refcount of trans_mod in error case in parse_opts()
[ Upstream commit c290fba8c4ce6530cd941ea14db5a4ac2f77183f ]
In my testing, the second mount will fail after umounting successfully.
The reason is that we put refcount of trans_mod in the correct case
rather than the error case in parse_opts() at last. That will cause the
refcount decrease to -1, and when we try to get trans_mod again in
try_module_get(), we could only increase refcount to 0 which will cause
failure as follows:
parse_opts
v9fs_get_trans_by_name
try_module_get : return NULL to caller which cause error
So we should put refcount of trans_mod in error case.
Link: http://lkml.kernel.org/r/5B3F39A0.2030509@huawei.com
Fixes: 9421c3e64137ec ("net/9p/client.c: fix potential refcnt problem of trans module")
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Dominique Martinet <dominique.martinet@cea.fr>
Tested-by: Dominique Martinet <dominique.martinet@cea.fr>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/9p/client.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/9p/client.c b/net/9p/client.c index 21e6df1cc70f..0ad6993aaa9b 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -228,7 +228,8 @@ static int parse_opts(char *opts, struct p9_client *clnt) } free_and_return: - v9fs_put_trans(clnt->trans_mod); + if (ret) + v9fs_put_trans(clnt->trans_mod); kfree(tmp_options); return ret; } |