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| author | Ido Schimmel <idosch@nvidia.com> | 2023-08-23 09:43:48 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-30 16:31:56 +0200 |
| commit | 42c8406432e730cb7442d97ecfdbf47084a5af4d (patch) | |
| tree | f221eb25be4fee00757b4b5b4a7b3444afe2e004 /net/core | |
| parent | 058a52e061c535a58269c57c4229eacafbdf7de1 (diff) | |
| download | linux-stable-42c8406432e730cb7442d97ecfdbf47084a5af4d.tar.gz linux-stable-42c8406432e730cb7442d97ecfdbf47084a5af4d.tar.bz2 linux-stable-42c8406432e730cb7442d97ecfdbf47084a5af4d.zip | |
rtnetlink: Reject negative ifindexes in RTM_NEWLINK
[ Upstream commit 30188bd7838c16a98a520db1fe9df01ffc6ed368 ]
Negative ifindexes are illegal, but the kernel does not validate the
ifindex in the ancillary header of RTM_NEWLINK messages, resulting in
the kernel generating a warning [1] when such an ifindex is specified.
Fix by rejecting negative ifindexes.
[1]
WARNING: CPU: 0 PID: 5031 at net/core/dev.c:9593 dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9593
[...]
Call Trace:
<TASK>
register_netdevice+0x69a/0x1490 net/core/dev.c:10081
br_dev_newlink+0x27/0x110 net/bridge/br_netlink.c:1552
rtnl_newlink_create net/core/rtnetlink.c:3471 [inline]
__rtnl_newlink+0x115e/0x18c0 net/core/rtnetlink.c:3688
rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3701
rtnetlink_rcv_msg+0x439/0xd30 net/core/rtnetlink.c:6427
netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545
netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368
netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910
sock_sendmsg_nosec net/socket.c:728 [inline]
sock_sendmsg+0xd9/0x180 net/socket.c:751
____sys_sendmsg+0x6ac/0x940 net/socket.c:2538
___sys_sendmsg+0x135/0x1d0 net/socket.c:2592
__sys_sendmsg+0x117/0x1e0 net/socket.c:2621
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: 38f7b870d4a6 ("[RTNETLINK]: Link creation API")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230823064348.2252280-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/rtnetlink.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 79f62517e24a..794db633f1c9 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2702,7 +2702,10 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, ifm = nlmsg_data(nlh); if (ifm->ifi_index > 0) dev = __dev_get_by_index(net, ifm->ifi_index); - else if (tb[IFLA_IFNAME]) + else if (ifm->ifi_index < 0) { + NL_SET_ERR_MSG(extack, "ifindex can't be negative"); + return -EINVAL; + } else if (tb[IFLA_IFNAME]) dev = __dev_get_by_name(net, ifname); else goto errout; |