0.0
NA
CVE-2021-47136
Openvswitch TC skb extension Uninitialized Memory Vulnerability
Description

In the Linux kernel, the following vulnerability has been resolved: net: zero-initialize tc skb extension on allocation Function skb_ext_add() doesn't initialize created skb extension with any value and leaves it up to the user. However, since extension of type TC_SKB_EXT originally contained only single value tc_skb_ext->chain its users used to just assign the chain value without setting whole extension memory to zero first. This assumption changed when TC_SKB_EXT extension was extended with additional fields but not all users were updated to initialize the new fields which leads to use of uninitialized memory afterwards. UBSAN log: [ 778.299821] UBSAN: invalid-load in net/openvswitch/flow.c:899:28 [ 778.301495] load of value 107 is not a valid value for type '_Bool' [ 778.303215] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7+ #2 [ 778.304933] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 778.307901] Call Trace: [ 778.308680] <IRQ> [ 778.309358] dump_stack+0xbb/0x107 [ 778.310307] ubsan_epilogue+0x5/0x40 [ 778.311167] __ubsan_handle_load_invalid_value.cold+0x43/0x48 [ 778.312454] ? memset+0x20/0x40 [ 778.313230] ovs_flow_key_extract.cold+0xf/0x14 [openvswitch] [ 778.314532] ovs_vport_receive+0x19e/0x2e0 [openvswitch] [ 778.315749] ? ovs_vport_find_upcall_portid+0x330/0x330 [openvswitch] [ 778.317188] ? create_prof_cpu_mask+0x20/0x20 [ 778.318220] ? arch_stack_walk+0x82/0xf0 [ 778.319153] ? secondary_startup_64_no_verify+0xb0/0xbb [ 778.320399] ? stack_trace_save+0x91/0xc0 [ 778.321362] ? stack_trace_consume_entry+0x160/0x160 [ 778.322517] ? lock_release+0x52e/0x760 [ 778.323444] netdev_frame_hook+0x323/0x610 [openvswitch] [ 778.324668] ? ovs_netdev_get_vport+0xe0/0xe0 [openvswitch] [ 778.325950] __netif_receive_skb_core+0x771/0x2db0 [ 778.327067] ? lock_downgrade+0x6e0/0x6f0 [ 778.328021] ? lock_acquire+0x565/0x720 [ 778.328940] ? generic_xdp_tx+0x4f0/0x4f0 [ 778.329902] ? inet_gro_receive+0x2a7/0x10a0 [ 778.330914] ? lock_downgrade+0x6f0/0x6f0 [ 778.331867] ? udp4_gro_receive+0x4c4/0x13e0 [ 778.332876] ? lock_release+0x52e/0x760 [ 778.333808] ? dev_gro_receive+0xcc8/0x2380 [ 778.334810] ? lock_downgrade+0x6f0/0x6f0 [ 778.335769] __netif_receive_skb_list_core+0x295/0x820 [ 778.336955] ? process_backlog+0x780/0x780 [ 778.337941] ? mlx5e_rep_tc_netdevice_event_unregister+0x20/0x20 [mlx5_core] [ 778.339613] ? seqcount_lockdep_reader_access.constprop.0+0xa7/0xc0 [ 778.341033] ? kvm_clock_get_cycles+0x14/0x20 [ 778.342072] netif_receive_skb_list_internal+0x5f5/0xcb0 [ 778.343288] ? __kasan_kmalloc+0x7a/0x90 [ 778.344234] ? mlx5e_handle_rx_cqe_mpwrq+0x9e0/0x9e0 [mlx5_core] [ 778.345676] ? mlx5e_xmit_xdp_frame_mpwqe+0x14d0/0x14d0 [mlx5_core] [ 778.347140] ? __netif_receive_skb_list_core+0x820/0x820 [ 778.348351] ? mlx5e_post_rx_mpwqes+0xa6/0x25d0 [mlx5_core] [ 778.349688] ? napi_gro_flush+0x26c/0x3c0 [ 778.350641] napi_complete_done+0x188/0x6b0 [ 778.351627] mlx5e_napi_poll+0x373/0x1b80 [mlx5_core] [ 778.352853] __napi_poll+0x9f/0x510 [ 778.353704] ? mlx5_flow_namespace_set_mode+0x260/0x260 [mlx5_core] [ 778.355158] net_rx_action+0x34c/0xa40 [ 778.356060] ? napi_threaded_poll+0x3d0/0x3d0 [ 778.357083] ? sched_clock_cpu+0x18/0x190 [ 778.358041] ? __common_interrupt+0x8e/0x1a0 [ 778.359045] __do_softirq+0x1ce/0x984 [ 778.359938] __irq_exit_rcu+0x137/0x1d0 [ 778.360865] irq_exit_rcu+0xa/0x20 [ 778.361708] common_interrupt+0x80/0xa0 [ 778.362640] </IRQ> [ 778.363212] asm_common_interrupt+0x1e/0x40 [ 778.364204] RIP: 0010:native_safe_halt+0xe/0x10 [ 778.365273] Code: 4f ff ff ff 4c 89 e7 e8 50 3f 40 fe e9 dc fe ff ff 48 89 df e8 43 3f 40 fe eb 90 cc e9 07 00 00 00 0f 00 2d 74 05 62 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 64 05 62 00 f4 c3 cc cc 0f 1f 44 00 [ 778.369355] RSP: 0018:ffffffff84407e48 EFLAGS: 00000246 [ 778.370570] RAX ---truncated---

INFO

Published Date :

March 25, 2024, 9:15 a.m.

Last Modified :

March 25, 2024, 1:47 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

Exploitability Score :

Affected Products

The following products are affected by CVE-2021-47136 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-47136.

URL Resource
https://git.kernel.org/stable/c/86ab133b695ed7ba1f8786b12f4ca43137ad8c18
https://git.kernel.org/stable/c/9453d45ecb6c2199d72e73c993e9d98677a2801b
https://git.kernel.org/stable/c/ac493452e937b8939eaf2d24cac51a4804b6c20e

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-47136 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-47136 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 28, 2024

    Action Type Old Value New Value
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Mar. 25, 2024

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: net: zero-initialize tc skb extension on allocation Function skb_ext_add() doesn't initialize created skb extension with any value and leaves it up to the user. However, since extension of type TC_SKB_EXT originally contained only single value tc_skb_ext->chain its users used to just assign the chain value without setting whole extension memory to zero first. This assumption changed when TC_SKB_EXT extension was extended with additional fields but not all users were updated to initialize the new fields which leads to use of uninitialized memory afterwards. UBSAN log: [ 778.299821] UBSAN: invalid-load in net/openvswitch/flow.c:899:28 [ 778.301495] load of value 107 is not a valid value for type '_Bool' [ 778.303215] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7+ #2 [ 778.304933] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 778.307901] Call Trace: [ 778.308680] <IRQ> [ 778.309358] dump_stack+0xbb/0x107 [ 778.310307] ubsan_epilogue+0x5/0x40 [ 778.311167] __ubsan_handle_load_invalid_value.cold+0x43/0x48 [ 778.312454] ? memset+0x20/0x40 [ 778.313230] ovs_flow_key_extract.cold+0xf/0x14 [openvswitch] [ 778.314532] ovs_vport_receive+0x19e/0x2e0 [openvswitch] [ 778.315749] ? ovs_vport_find_upcall_portid+0x330/0x330 [openvswitch] [ 778.317188] ? create_prof_cpu_mask+0x20/0x20 [ 778.318220] ? arch_stack_walk+0x82/0xf0 [ 778.319153] ? secondary_startup_64_no_verify+0xb0/0xbb [ 778.320399] ? stack_trace_save+0x91/0xc0 [ 778.321362] ? stack_trace_consume_entry+0x160/0x160 [ 778.322517] ? lock_release+0x52e/0x760 [ 778.323444] netdev_frame_hook+0x323/0x610 [openvswitch] [ 778.324668] ? ovs_netdev_get_vport+0xe0/0xe0 [openvswitch] [ 778.325950] __netif_receive_skb_core+0x771/0x2db0 [ 778.327067] ? lock_downgrade+0x6e0/0x6f0 [ 778.328021] ? lock_acquire+0x565/0x720 [ 778.328940] ? generic_xdp_tx+0x4f0/0x4f0 [ 778.329902] ? inet_gro_receive+0x2a7/0x10a0 [ 778.330914] ? lock_downgrade+0x6f0/0x6f0 [ 778.331867] ? udp4_gro_receive+0x4c4/0x13e0 [ 778.332876] ? lock_release+0x52e/0x760 [ 778.333808] ? dev_gro_receive+0xcc8/0x2380 [ 778.334810] ? lock_downgrade+0x6f0/0x6f0 [ 778.335769] __netif_receive_skb_list_core+0x295/0x820 [ 778.336955] ? process_backlog+0x780/0x780 [ 778.337941] ? mlx5e_rep_tc_netdevice_event_unregister+0x20/0x20 [mlx5_core] [ 778.339613] ? seqcount_lockdep_reader_access.constprop.0+0xa7/0xc0 [ 778.341033] ? kvm_clock_get_cycles+0x14/0x20 [ 778.342072] netif_receive_skb_list_internal+0x5f5/0xcb0 [ 778.343288] ? __kasan_kmalloc+0x7a/0x90 [ 778.344234] ? mlx5e_handle_rx_cqe_mpwrq+0x9e0/0x9e0 [mlx5_core] [ 778.345676] ? mlx5e_xmit_xdp_frame_mpwqe+0x14d0/0x14d0 [mlx5_core] [ 778.347140] ? __netif_receive_skb_list_core+0x820/0x820 [ 778.348351] ? mlx5e_post_rx_mpwqes+0xa6/0x25d0 [mlx5_core] [ 778.349688] ? napi_gro_flush+0x26c/0x3c0 [ 778.350641] napi_complete_done+0x188/0x6b0 [ 778.351627] mlx5e_napi_poll+0x373/0x1b80 [mlx5_core] [ 778.352853] __napi_poll+0x9f/0x510 [ 778.353704] ? mlx5_flow_namespace_set_mode+0x260/0x260 [mlx5_core] [ 778.355158] net_rx_action+0x34c/0xa40 [ 778.356060] ? napi_threaded_poll+0x3d0/0x3d0 [ 778.357083] ? sched_clock_cpu+0x18/0x190 [ 778.358041] ? __common_interrupt+0x8e/0x1a0 [ 778.359045] __do_softirq+0x1ce/0x984 [ 778.359938] __irq_exit_rcu+0x137/0x1d0 [ 778.360865] irq_exit_rcu+0xa/0x20 [ 778.361708] common_interrupt+0x80/0xa0 [ 778.362640] </IRQ> [ 778.363212] asm_common_interrupt+0x1e/0x40 [ 778.364204] RIP: 0010:native_safe_halt+0xe/0x10 [ 778.365273] Code: 4f ff ff ff 4c 89 e7 e8 50 3f 40 fe e9 dc fe ff ff 48 89 df e8 43 3f 40 fe eb 90 cc e9 07 00 00 00 0f 00 2d 74 05 62 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 64 05 62 00 f4 c3 cc cc 0f 1f 44 00 [ 778.369355] RSP: 0018:ffffffff84407e48 EFLAGS: 00000246 [ 778.370570] RAX ---truncated---
    Added Reference kernel.org https://git.kernel.org/stable/c/ac493452e937b8939eaf2d24cac51a4804b6c20e [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/86ab133b695ed7ba1f8786b12f4ca43137ad8c18 [No types assigned]
    Added Reference kernel.org https://git.kernel.org/stable/c/9453d45ecb6c2199d72e73c993e9d98677a2801b [No types assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-47136 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-47136 weaknesses.

NONE - Vulnerability Scoring System
: