| From f26c505053b8927551bedb8a758c5878495eee4b Mon Sep 17 00:00:00 2001 |
| From: Taehee Yoo <ap420073@gmail.com> |
| Date: Thu, 27 Feb 2020 12:23:52 +0000 |
| Subject: [PATCH] net: rmnet: fix NULL pointer dereference in rmnet_newlink() |
| |
| commit 93b5cbfa9636d385126f211dca9efa7e3f683202 upstream. |
| |
| rmnet registers IFLA_LINK interface as a lower interface. |
| But, IFLA_LINK could be NULL. |
| In the current code, rmnet doesn't check IFLA_LINK. |
| So, panic would occur. |
| |
| Test commands: |
| modprobe rmnet |
| ip link add rmnet0 type rmnet mux_id 1 |
| |
| Splat looks like: |
| [ 36.826109][ T1115] general protection fault, probably for non-canonical address 0xdffffc0000000000I |
| [ 36.838817][ T1115] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] |
| [ 36.839908][ T1115] CPU: 1 PID: 1115 Comm: ip Not tainted 5.6.0-rc1+ #447 |
| [ 36.840569][ T1115] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 |
| [ 36.841408][ T1115] RIP: 0010:rmnet_newlink+0x54/0x510 [rmnet] |
| [ 36.841986][ T1115] Code: 83 ec 18 48 c1 e9 03 80 3c 01 00 0f 85 d4 03 00 00 48 8b 6a 28 48 b8 00 00 00 00 00 c |
| [ 36.843923][ T1115] RSP: 0018:ffff8880b7e0f1c0 EFLAGS: 00010247 |
| [ 36.844756][ T1115] RAX: dffffc0000000000 RBX: ffff8880d14cca00 RCX: 1ffff11016fc1e99 |
| [ 36.845859][ T1115] RDX: 0000000000000000 RSI: ffff8880c3d04000 RDI: 0000000000000004 |
| [ 36.846961][ T1115] RBP: 0000000000000000 R08: ffff8880b7e0f8b0 R09: ffff8880b6ac2d90 |
| [ 36.848020][ T1115] R10: ffffffffc0589a40 R11: ffffed1016d585b7 R12: ffffffff88ceaf80 |
| [ 36.848788][ T1115] R13: ffff8880c3d04000 R14: ffff8880b7e0f8b0 R15: ffff8880c3d04000 |
| [ 36.849546][ T1115] FS: 00007f50ab3360c0(0000) GS:ffff8880da000000(0000) knlGS:0000000000000000 |
| [ 36.851784][ T1115] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| [ 36.852422][ T1115] CR2: 000055871afe5ab0 CR3: 00000000ae246001 CR4: 00000000000606e0 |
| [ 36.853181][ T1115] Call Trace: |
| [ 36.853514][ T1115] __rtnl_newlink+0xbdb/0x1270 |
| [ 36.853967][ T1115] ? lock_downgrade+0x6e0/0x6e0 |
| [ 36.854420][ T1115] ? rtnl_link_unregister+0x220/0x220 |
| [ 36.854936][ T1115] ? lock_acquire+0x164/0x3b0 |
| [ 36.855376][ T1115] ? is_bpf_image_address+0xff/0x1d0 |
| [ 36.855884][ T1115] ? rtnl_newlink+0x4c/0x90 |
| [ 36.856304][ T1115] ? kernel_text_address+0x111/0x140 |
| [ 36.856857][ T1115] ? __kernel_text_address+0xe/0x30 |
| [ 36.857440][ T1115] ? unwind_get_return_address+0x5f/0xa0 |
| [ 36.858063][ T1115] ? create_prof_cpu_mask+0x20/0x20 |
| [ 36.858644][ T1115] ? arch_stack_walk+0x83/0xb0 |
| [ 36.859171][ T1115] ? stack_trace_save+0x82/0xb0 |
| [ 36.859710][ T1115] ? stack_trace_consume_entry+0x160/0x160 |
| [ 36.860357][ T1115] ? deactivate_slab.isra.78+0x2c5/0x800 |
| [ 36.860928][ T1115] ? kasan_unpoison_shadow+0x30/0x40 |
| [ 36.861520][ T1115] ? kmem_cache_alloc_trace+0x135/0x350 |
| [ 36.862125][ T1115] ? rtnl_newlink+0x4c/0x90 |
| [ 36.864073][ T1115] rtnl_newlink+0x65/0x90 |
| [ ... ] |
| |
| Fixes: ceed73a2cf4a ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation") |
| Signed-off-by: Taehee Yoo <ap420073@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c |
| index 06de59521fc4..471e3b2a1403 100644 |
| --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c |
| +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_config.c |
| @@ -135,6 +135,11 @@ static int rmnet_newlink(struct net *src_net, struct net_device *dev, |
| int err = 0; |
| u16 mux_id; |
| |
| + if (!tb[IFLA_LINK]) { |
| + NL_SET_ERR_MSG_MOD(extack, "link not specified"); |
| + return -EINVAL; |
| + } |
| + |
| real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK])); |
| if (!real_dev || !dev) |
| return -ENODEV; |
| -- |
| 2.7.4 |
| |