| Message ID | 20241028080515.3540779-1-ruanjinjie@huawei.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] netlink: Fix off-by-one error in netlink_proto_init() | expand |
On Mon, Oct 28, 2024 at 9:05 AM Jinjie Ruan <ruanjinjie@huawei.com> wrote: > > In the error path of netlink_proto_init(), frees the already allocated > bucket table for new hash tables in a loop, but the loop condition > terminates when the index reaches zero, which fails to free the first > bucket table at index zero. > > Check for >= 0 so that nl_table[0].hash is freed as well. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> > --- > net/netlink/af_netlink.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c > index 0a9287fadb47..9601b85dda95 100644 > --- a/net/netlink/af_netlink.c > +++ b/net/netlink/af_netlink.c > @@ -2936,7 +2936,7 @@ static int __init netlink_proto_init(void) > for (i = 0; i < MAX_LINKS; i++) { > if (rhashtable_init(&nl_table[i].hash, > &netlink_rhashtable_params) < 0) { > - while (--i > 0) > + while (--i >= 0) > rhashtable_destroy(&nl_table[i].hash); > kfree(nl_table); > goto panic; > -- Note that the host is going to panic, many other pieces of memory are left behind. A Fixes: tag seems unnecessary.
From: Jinjie Ruan <ruanjinjie@huawei.com> Date: Mon, 28 Oct 2024 16:05:15 +0800 > In the error path of netlink_proto_init(), frees the already allocated > bucket table for new hash tables in a loop, but the loop condition > terminates when the index reaches zero, which fails to free the first > bucket table at index zero. > > Check for >= 0 so that nl_table[0].hash is freed as well. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> > --- > net/netlink/af_netlink.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c > index 0a9287fadb47..9601b85dda95 100644 > --- a/net/netlink/af_netlink.c > +++ b/net/netlink/af_netlink.c > @@ -2936,7 +2936,7 @@ static int __init netlink_proto_init(void) > for (i = 0; i < MAX_LINKS; i++) { > if (rhashtable_init(&nl_table[i].hash, > &netlink_rhashtable_params) < 0) { > - while (--i > 0) > + while (--i >= 0) > rhashtable_destroy(&nl_table[i].hash); > kfree(nl_table); > goto panic; I remember the same question was posted in the past. https://lore.kernel.org/netdev/ZfOalln%2FmyRNOkH6@cy-server/ As Eric alreday pointed out (and as mentioned in the thread above too), it's going to panic, and we need not clean up resources here, so let's remove rhashtable_destroy() and kfree() instead of adjusting the loop condition.
On 2024/10/29 2:24, Kuniyuki Iwashima wrote: > From: Jinjie Ruan <ruanjinjie@huawei.com> > Date: Mon, 28 Oct 2024 16:05:15 +0800 >> In the error path of netlink_proto_init(), frees the already allocated >> bucket table for new hash tables in a loop, but the loop condition >> terminates when the index reaches zero, which fails to free the first >> bucket table at index zero. >> >> Check for >= 0 so that nl_table[0].hash is freed as well. >> >> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") >> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> >> --- >> net/netlink/af_netlink.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c >> index 0a9287fadb47..9601b85dda95 100644 >> --- a/net/netlink/af_netlink.c >> +++ b/net/netlink/af_netlink.c >> @@ -2936,7 +2936,7 @@ static int __init netlink_proto_init(void) >> for (i = 0; i < MAX_LINKS; i++) { >> if (rhashtable_init(&nl_table[i].hash, >> &netlink_rhashtable_params) < 0) { >> - while (--i > 0) >> + while (--i >= 0) >> rhashtable_destroy(&nl_table[i].hash); >> kfree(nl_table); >> goto panic; > > I remember the same question was posted in the past. > https://lore.kernel.org/netdev/ZfOalln%2FmyRNOkH6@cy-server/ > > As Eric alreday pointed out (and as mentioned in the thread above too), > it's going to panic, and we need not clean up resources here, so let's > remove rhashtable_destroy() and kfree() instead of adjusting the loop > condition. Thank you very much, remove it is fine. >
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 0a9287fadb47..9601b85dda95 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2936,7 +2936,7 @@ static int __init netlink_proto_init(void) for (i = 0; i < MAX_LINKS; i++) { if (rhashtable_init(&nl_table[i].hash, &netlink_rhashtable_params) < 0) { - while (--i > 0) + while (--i >= 0) rhashtable_destroy(&nl_table[i].hash); kfree(nl_table); goto panic;
In the error path of netlink_proto_init(), frees the already allocated bucket table for new hash tables in a loop, but the loop condition terminates when the index reaches zero, which fails to free the first bucket table at index zero. Check for >= 0 so that nl_table[0].hash is freed as well. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)