CVE-2021-47099High· 7.8▾ TwilightIn the Linux kernel, the following vulnerability has been resolved: veth: ensure skb entering GRO are not cloned. After commit d3256efd8e8b ("veth: allow enabling NAPI even without XDP"), if GRO is enabled on a veth device and TSO is d…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 42.9 · likelihood 0 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Exploit-prediction probability, daily snapshots since Aug 5.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.2%
0.2% → 0.2%
In the Linux kernel, the following vulnerability has been resolved:
veth: ensure skb entering GRO are not cloned.
After commit d3256efd8e8b ("veth: allow enabling NAPI even without XDP"), if GRO is enabled on a veth device and TSO is disabled on the peer device, TCP skbs will go through the NAPI callback. If there is no XDP program attached, the veth code does not perform any share check, and shared/cloned skbs could enter the GRO engine.
Ignat reported a BUG triggered later-on due to the above condition:
[ 53.970529][ C1] kernel BUG at net/core/skbuff.c:3574! [ 53.981755][ C1] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI [ 53.982634][ C1] CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.16.0-rc5+ #25 [ 53.982634][ C1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 53.982634][ C1] RIP: 0010:skb_shift+0x13ef/0x23b0 [ 53.982634][ C1] Code: ea 03 0f b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 41 0c 00 00 41 80 7f 02 00 4d 8d b5 d0 00 00 00 0f 85 74 f5 ff ff <0f> 0b 4d 8d 77 20 be 04 00 00 00 4c 89 44 24 78 4c 89 f7 4c 89 8c [ 53.982634][ C1] RSP: 0018:ffff8881008f7008 EFLAGS: 00010246 [ 53.982634][ C1] RAX: 0000000000000000 RBX: ffff8881180b4c80 RCX: 0000000000000000 [ 53.982634][ C1] RDX: 0000000000000002 RSI: ffff8881180b4d3c RDI: ffff88810bc9cac2 [ 53.982634][ C1] RBP: ffff8881008f70b8 R08: ffff8881180b4cf4 R09: ffff8881180b4cf0 [ 53.982634][ C1] R10: ffffed1022999e5c R11: 0000000000000002 R12: 0000000000000590 [ 53.982634][ C1] R13: ffff88810f940c80 R14: ffff88810f940d50 R15: ffff88810bc9cac0 [ 53.982634][ C1] FS: 0000000000000000(0000) GS:ffff888235880000(0000) knlGS:0000000000000000 [ 53.982634][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 53.982634][ C1] CR2: 00007ff5f9b86680 CR3: 0000000108ce8004 CR4: 0000000000170ee0 [ 53.982634][ C1] Call Trace: [ 53.982634][ C1] <TASK> [ 53.982634][ C1] tcp_sacktag_walk+0xaba/0x18e0 [ 53.982634][ C1] tcp_sacktag_write_queue+0xe7b/0x3460 [ 53.982634][ C1] tcp_ack+0x2666/0x54b0 [ 53.982634][ C1] tcp_rcv_established+0x4d9/0x20f0 [ 53.982634][ C1] tcp_v4_do_rcv+0x551/0x810 [ 53.982634][ C1] tcp_v4_rcv+0x22ed/0x2ed0 [ 53.982634][ C1] ip_protocol_deliver_rcu+0x96/0xaf0 [ 53.982634][ C1] ip_local_deliver_finish+0x1e0/0x2f0 [ 53.982634][ C1] ip_sublist_rcv_finish+0x211/0x440 [ 53.982634][ C1] ip_list_rcv_finish.constprop.0+0x424/0x660 [ 53.982634][ C1] ip_list_rcv+0x2c8/0x410 [ 53.982634][ C1] __netif_receive_skb_list_core+0x65c/0x910 [ 53.982634][ C1] netif_receive_skb_list_internal+0x5f9/0xcb0 [ 53.982634][ C1] napi_complete_done+0x188/0x6e0 [ 53.982634][ C1] gro_cell_poll+0x10c/0x1d0 [ 53.982634][ C1] __napi_poll+0xa1/0x530 [ 53.982634][ C1] net_rx_action+0x567/0x1270 [ 53.982634][ C1] __do_softirq+0x28a/0x9ba [ 53.982634][ C1] run_ksoftirqd+0x32/0x60 [ 53.982634][ C1] smpboot_thread_fn+0x559/0x8c0 [ 53.982634][ C1] kthread+0x3b9/0x490 [ 53.982634][ C1] ret_from_fork+0x22/0x30 [ 53.982634][ C1] </TASK>
Address the issue by skipping the GRO stage for shared or cloned skbs. To reduce the chance of OoO, try to unclone the skbs before giving up.
v1 -> v2:
linux_kernel >= 5.13, < 5.15.12linux_kernel = 5.16Upgrade past the affected range:
linux_kernel 5.15.12Connected by shared product, vendor, weakness, or advisory.
CVE-2022-36280Medium· 6.3An out-of-bounds(OOB) memory access vulnerability was found in vmwgfx driver in drivers/gpu/vmxgfx/vmxgfx_kms.c in GPU component in the Linux kernel with device file '/dev/dri/renderD128 (or Dxxx)'
CVE-2022-36123High· 7.8The Linux kernel before 5.18.13 lacks a certain clear operation for the block starting symbol (.bss)
CVE-2022-34918High· 7.8An issue was discovered in the Linux kernel through 5.18.9
CVE-2022-32250High· 7.8net/netfilter/nf_tables_api.c in the Linux kernel through 5.18.1 allows a local user (able to create user/net namespaces) to escalate privileges to root because an incorrect NFT_STATEFUL_EXPR check leads to a use-after-free.
CVE-2022-32296Low· 3.3The Linux kernel before 5.17.9 allows TCP servers to identify clients by observing what source ports are used
CVE-2022-3104Medium· 5.5An issue was discovered in the Linux kernel through 5.16-rc6