CVE-2024-56636

Published Dec 27, 2024

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: geneve: do not assume mac header is set in geneve_xmit_skb() We should not assume mac header is set in output path. Use skb_eth_hdr() instead of eth_hdr() to fix the issue. sysbot reported the following : WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 skb_mac_header include/linux/skbuff.h:3052 [inline] WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 eth_hdr include/linux/if_ether.h:24 [inline] WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit_skb drivers/net/geneve.c:898 [inline] WARNING: CPU: 0 PID: 11635 at include/linux/skbuff.h:3052 geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039 Modules linked in: CPU: 0 UID: 0 PID: 11635 Comm: syz.4.1423 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:skb_mac_header include/linux/skbuff.h:3052 [inline] RIP: 0010:eth_hdr include/linux/if_ether.h:24 [inline] RIP: 0010:geneve_xmit_skb drivers/net/geneve.c:898 [inline] RIP: 0010:geneve_xmit+0x4c38/0x5730 drivers/net/geneve.c:1039 Code: 21 c6 02 e9 35 d4 ff ff e8 a5 48 4c fb 90 0f 0b 90 e9 fd f5 ff ff e8 97 48 4c fb 90 0f 0b 90 e9 d8 f5 ff ff e8 89 48 4c fb 90 <0f> 0b 90 e9 41 e4 ff ff e8 7b 48 4c fb 90 0f 0b 90 e9 cd e7 ff ff RSP: 0018:ffffc90003b2f870 EFLAGS: 00010283 RAX: 000000000000037a RBX: 000000000000ffff RCX: ffffc9000dc3d000 RDX: 0000000000080000 RSI: ffffffff86428417 RDI: 0000000000000003 RBP: ffffc90003b2f9f0 R08: 0000000000000003 R09: 000000000000ffff R10: 000000000000ffff R11: 0000000000000002 R12: ffff88806603c000 R13: 0000000000000000 R14: ffff8880685b2780 R15: 0000000000000e23 FS: 00007fdc2deed6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30a1dff8 CR3: 0000000056b8c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __netdev_start_xmit include/linux/netdevice.h:5002 [inline] netdev_start_xmit include/linux/netdevice.h:5011 [inline] __dev_direct_xmit+0x58a/0x720 net/core/dev.c:4490 dev_direct_xmit include/linux/netdevice.h:3181 [inline] packet_xmit+0x1e4/0x360 net/packet/af_packet.c:285 packet_snd net/packet/af_packet.c:3146 [inline] packet_sendmsg+0x2700/0x5660 net/packet/af_packet.c:3178 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg net/socket.c:726 [inline] __sys_sendto+0x488/0x4f0 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2200 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
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