| Message ID | 1543302127-14435-1-git-send-email-bianpan2016@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | libceph: fix use after free | expand |
Hello! On 27.11.2018 10:02, Pan Bian wrote: > The function ceph_monc_handle_map calls kfree(old) to free the old > monitor map, old points to monc->monmap. However, after that, it reads > monc->monmap->epoch and passes it to __ceph_monc_got_map. This result in > a use-after-free bug. The patch moves the free operation after the call > to __ceph_monc_got_map. > > Fixes: 82dcabad750("libceph: revamp subs code, switch to SUBSCRIBE2 Space needed before (. > protocol") Never break up the commit summary in this tag. > Signed-off-by: Pan Bian <bianpan2016@163.com> [...] MBR, Sergei
On Tue, Nov 27, 2018 at 11:47:56AM +0300, Sergei Shtylyov wrote: > Hello! > > On 27.11.2018 10:02, Pan Bian wrote: > > >The function ceph_monc_handle_map calls kfree(old) to free the old > >monitor map, old points to monc->monmap. However, after that, it reads > >monc->monmap->epoch and passes it to __ceph_monc_got_map. This result in > >a use-after-free bug. The patch moves the free operation after the call > >to __ceph_monc_got_map. > > > >Fixes: 82dcabad750("libceph: revamp subs code, switch to SUBSCRIBE2 > > Space needed before (. > > >protocol") > > Never break up the commit summary in this tag. Thanks for the guidance, I will correct it. > > >Signed-off-by: Pan Bian <bianpan2016@163.com> > [...] > > MBR, Sergei
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c index 18deb3d..05ef5aa 100644 --- a/net/ceph/mon_client.c +++ b/net/ceph/mon_client.c @@ -478,9 +478,10 @@ static void ceph_monc_handle_map(struct ceph_mon_client *monc, } client->monc.monmap = monmap; - kfree(old); __ceph_monc_got_map(monc, CEPH_SUB_MONMAP, monc->monmap->epoch); + kfree(old); + client->have_fsid = true; out:
The function ceph_monc_handle_map calls kfree(old) to free the old monitor map, old points to monc->monmap. However, after that, it reads monc->monmap->epoch and passes it to __ceph_monc_got_map. This result in a use-after-free bug. The patch moves the free operation after the call to __ceph_monc_got_map. Fixes: 82dcabad750("libceph: revamp subs code, switch to SUBSCRIBE2 protocol") Signed-off-by: Pan Bian <bianpan2016@163.com> --- net/ceph/mon_client.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)