On Fri, Apr 11, 2014 at 10:35:33AM +0200, Mateusz Guzik wrote: > On Fri, Apr 11, 2014 at 01:37:08PM -0400, Wang, Xiaoming wrote: > > There is a memory leak in ping. Current group_info had been got in > > ping_init_sock and group_info->usage increased. > > But the usage hasn't decreased anywhere in ping. > > This will make this group_info never freed and cause memory leak. > > > > Memory leak is only one of possible side-effects, thus I believe commit > message should be adjusted. > > This is a typical refcount leak exploitable by unprivileged users, so > side effects can range from nothing through memory leaks and crashes to > possibly privilege escalation. > > That said losing ' and cause memory leak' from your commit message > would be fine in my opinion. >
Huh, not sure why I wrote that last sentence, it does not make much sense. Sorry. There is a pending CVE request for this bug: http://seclists.org/oss-sec/2014/q2/97 The bug was introduced with: commit c319b4d76b9e583a5d88d6bf190e079c4e43213d Author: Vasiliy Kulikov <seg...@openwall.com> Date: Fri May 13 10:01:00 2011 +0000 net: ipv4: add IPPROTO_ICMP socket kind starting with 3.0 kernel. > See also a nit below. > > > --- > > net/ipv4/ping.c | 11 ++++++++--- > > 1 files changed, 8 insertions(+), 3 deletions(-) > > > > diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c > > index f4b19e5..2af7b1f 100644 > > --- a/net/ipv4/ping.c > > +++ b/net/ipv4/ping.c > > @@ -255,23 +255,28 @@ int ping_init_sock(struct sock *sk) > > struct group_info *group_info = get_current_groups(); > > int i, j, count = group_info->ngroups; > > kgid_t low, high; > > + int ret = 0; > > > > inet_get_ping_group_range_net(net, &low, &high); > > if (gid_lte(low, group) && gid_lte(group, high)) > > - return 0; > > + goto out_release_group; > > > > Since group_info is not even used here maybe it would be better to leave > return 0 as it is and call get_current_groups before the loop? > > > for (i = 0; i < group_info->nblocks; i++) { > > int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); > > for (j = 0; j < cp_count; j++) { > > kgid_t gid = group_info->blocks[i][j]; > > if (gid_lte(low, gid) && gid_lte(gid, high)) > > - return 0; > > + goto out_release_group; > > } > > > > count -= cp_count; > > } > > > > - return -EACCES; > > + ret = -EACCES; > > + > > +out_release_group: > > + put_group_info(group_info); > > + return ret; > > } > > EXPORT_SYMBOL_GPL(ping_init_sock); > > > > -- > Mateusz Guzik -- Mateusz Guzik -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
