CVE-2022-49663

Published Feb 26, 2025

Last updated 8 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume mac header is set in skb_tunnel_check_pmtu() Recently added debug in commit f9aefd6b2aa3 ("net: warn if mac header was not set") caught a bug in skb_tunnel_check_pmtu(), as shown in this syzbot report [1]. In ndo_start_xmit() paths, there is really no need to use skb->mac_header, because skb->data is supposed to point at it. [1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Modules linked in: CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline] RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413 Code: 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 80 3c 02 00 0f 84 b9 fe ff ff 4c 89 ff e8 7c 0f d7 f9 e9 ac fe ff ff e8 c2 13 8a f9 <0f> 0b e9 28 fc ff ff e8 b6 13 8a f9 48 8b 54 24 70 48 b8 00 00 00 RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212 RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000 RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003 RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000000 R12: 000000000000ffff R13: 0000000000000000 R14: 000000000000ffcd R15: 000000000000001f FS: 00007f3babba9700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000080 CR3: 0000000075319000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> geneve_xmit_skb drivers/net/geneve.c:927 [inline] geneve_xmit+0xcf8/0x35d0 drivers/net/geneve.c:1107 __netdev_start_xmit include/linux/netdevice.h:4805 [inline] netdev_start_xmit include/linux/netdevice.h:4819 [inline] __dev_direct_xmit+0x500/0x730 net/core/dev.c:4309 dev_direct_xmit include/linux/netdevice.h:3007 [inline] packet_direct_xmit+0x1b8/0x2c0 net/packet/af_packet.c:282 packet_snd net/packet/af_packet.c:3073 [inline] packet_sendmsg+0x21f4/0x55d0 net/packet/af_packet.c:3104 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x6eb/0x810 net/socket.c:2489 ___sys_sendmsg+0xf3/0x170 net/socket.c:2543 __sys_sendmsg net/socket.c:2572 [inline] __do_sys_sendmsg net/socket.c:2581 [inline] __se_sys_sendmsg net/socket.c:2579 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2579 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f3baaa89109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3babba9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3baab9bf60 RCX: 00007f3baaa89109 RDX: 0000000000000000 RSI: 0000000020000a00 RDI: 0000000000000003 RBP: 00007f3baaae305d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe74f2543f R14: 00007f3babba9300 R15: 0000000000022000 </TASK>
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: coresight: tmc-etr: Fix race condition between sysfs and perf mode When trying to run perf and sysfs mode simultaneously, the WARN_ON() in tmc_etr_enable_hw() is triggered sometimes: WARNING: CPU: 42 PID: 3911571 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1060 tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] [..snip..] Call trace: tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] (P) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] (L) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] coresight_enable_path+0x1c8/0x218 [coresight] coresight_enable_sysfs+0xa4/0x228 [coresight] enable_source_store+0x58/0xa8 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2c8/0x388 ksys_write+0x74/0x108 __arm64_sys_write+0x24/0x38 el0_svc_common.constprop.0+0x64/0x148 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x130 el0t_64_sync_handler+0xc8/0xd0 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Since the enablement of sysfs mode is separeted into two critical regions, one for sysfs buffer allocation and another for hardware enablement, it's possible to race with the perf mode. Fix this by double check whether the perf mode's been used before enabling the hardware in sysfs mode. mode: [sysfs mode] [perf mode] tmc_etr_get_sysfs_buffer() spin_lock(&drvdata->spinlock) [sysfs buffer allocation] spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() drvdata->etr_buf = etr_perf->etr_buf spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() WARN_ON(drvdata->etr_buf) // WARN sicne etr_buf initialized at the perf side spin_unlock(&drvdata->spinlock) With this fix, we retain the check for CS_MODE_PERF in get_etr_sysfs_buf. This ensures we verify whether the perf mode's already running before we actually allocate the buffer. Then we can save the time of allocating/freeing the sysfs buffer if race with the perf mode.CVE-2026-46272