In the Linux kernel, the following vulnerability has been resolved:
net: fix use-after-free in tw_timer_handler
A real world panic issue was found as follow in Linux 5.4.
BUG: unable to handle page fault for address: ffffde49a863de28 PGD 7e6fe62067 P4D 7e6fe62067 PUD 7e6fe63067 PMD f51e064067 PTE 0 RIP: 0010:tw_timer_handler+0x20/0x40 Call Trace: <IRQ> call_timer_fn+0x2b/0x120 run_timer_softirq+0x1ef/0x450 __do_softirq+0x10d/0x2b8 irq_exit+0xc7/0xd0 smp_apic_timer_interrupt+0x68/0x120 apic_timer_interrupt+0xf/0x20
This issue was also reported since 2017 in the thread [1], unfortunately, the issue was still can be reproduced after fixing DCCP.
The ipv4_mib_exit_net is called before tcp_sk_exit_batch when a net namespace is destroyed since tcp_sk_ops is registered befrore ipv4_mib_ops, which means tcp_sk_ops is in the front of ipv4_mib_ops in the list of pernet_list. There will be a use-after-free on net->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net if there are some inflight time-wait timers.
This bug is not introduced by commit f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH") since the net_statistics is a global variable instead of dynamic allocation and freeing. Actually, commit 61a7e26028b9 ("mib: put net statistics on struct net") introduces the bug since it put net statistics on struct net and free it when net namespace is destroyed.
Moving init_ipv4_mibs() to the front of tcp_init() to fix this bug and replace pr_crit() with panic() since continuing is meaningless when init_ipv4_mibs() fails.
[1] https://groups.google.com/g/syzkaller/c/p1tn-_Kc6l4/m/smuL_FMAAgAJ?pli=1
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-livepatch-5.10.93-87.444Upgrade kernel-tools-develUpgrade perfUpgrade kernel-debuginfo-common-aarch64Upgrade bpftoolUpgrade kernel-develUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfoUpgrade kernel-livepatch-4.14.262-200.489Upgrade kernel-headersUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-toolsUpgrade perf-debuginfoUpgrade python-perf-debuginfoUpgrade kernelUpgrade bpftool-debuginfoUpgrade python-perf | Apr 25, 2024 | Feb 27, 2024 |
| Debian | — | Upgrade linux | Jul 30, 2024 | Feb 27, 2024 |
| Huawei Euleros 2_0_sp5 | — | Upgrade python-perfUpgrade kernel-develUpgrade kernel-headersUpgrade kernel-tools-libsUpgrade perfUpgrade kernel-toolsUpgrade kernel | Oct 8, 2024 | Feb 27, 2024 |
| Huawei Euleros 2_0_sp8 | — | Upgrade kernel-toolsUpgrade perfUpgrade python3-perfUpgrade kernel-develUpgrade python-perfUpgrade bpftoolUpgrade kernel-headersUpgrade kernel-tools-libsUpgrade kernel | Jul 23, 2024 | Feb 27, 2024 |
| Huawei Euleros 2_0_sp9 | — | Upgrade kernel-toolsUpgrade python3-perfUpgrade kernel-tools-libsUpgrade kernel | Jul 17, 2024 | Feb 27, 2024 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Feb 27, 2024 |
| Suse | — | Upgrade dlm-kmp-defaultUpgrade kernel-kvmsmall-vdsoUpgrade dlm-kmp-rtUpgrade reiserfs-kmp-rtUpgrade dtb-caviumUpgrade dtb-nvidiaUpgrade kernel-obs-buildUpgrade dtb-armUpgrade kernel-default-baseUpgrade kernel-rt-extraUpgrade kernel-debug-develUpgrade gfs2-kmp-defaultUpgrade kernel-azureUpgrade reiserfs-kmp-defaultUpgrade kselftests-kmp-rtUpgrade kernel-rt_debug-livepatch-develUpgrade kernel-default-livepatch-develUpgrade kernel-rt_debug-develUpgrade dtb-xilinxUpgrade ocfs2-kmp-azureUpgrade dtb-amdUpgrade cluster-md-kmp-rtUpgrade dtb-renesasUpgrade kernel-rt-optionalUpgrade kernel-64kb-extraUpgrade kernel-default-optionalUpgrade kselftests-kmp-defaultUpgrade kernel-develUpgrade ocfs2-kmp-defaultUpgrade kernel-rt-vdsoUpgrade kernel-debug-vdsoUpgrade kernel-defaultUpgrade dtb-rockchipUpgrade kselftests-kmp-azureUpgrade kernel-default-base-rebuildUpgrade reiserfs-kmp-azureUpgrade kernel-docsUpgrade dlm-kmp-azureUpgrade cluster-md-kmp-64kbUpgrade reiserfs-kmp-64kbUpgrade dtb-allwinnerUpgrade kernel-rt_debugUpgrade kernel-source-vanillaUpgrade kernel-source-rtUpgrade gfs2-kmp-azureUpgrade dtb-socionextUpgrade dtb-sprdUpgrade kernel-rt-develUpgrade dtb-exynosUpgrade ocfs2-kmp-64kbUpgrade gfs2-kmp-rtUpgrade dtb-apmUpgrade gfs2-kmp-64kbUpgrade dtb-freescaleUpgrade kernel-default-vdsoUpgrade dtb-amlogicUpgrade kernel-debugUpgrade kernel-64kb-develUpgrade kernel-azure-extraUpgrade dtb-appleUpgrade kernel-symsUpgrade kernel-rt_debug-vdsoUpgrade cluster-md-kmp-defaultUpgrade dtb-lgUpgrade dlm-kmp-64kbUpgrade kernel-azure-vdsoUpgrade kernel-obs-qaUpgrade kernel-kvmsmall-livepatch-develUpgrade kernel-default-extraUpgrade kernel-64kb-optionalUpgrade kernel-64kbUpgrade kernel-rt-livepatch-develUpgrade cluster-md-kmp-azureUpgrade kernel-kvmsmallUpgrade kernel-devel-azureUpgrade kernel-macrosUpgrade kernel-default-develUpgrade dtb-mediatekUpgrade kernel-kvmsmall-develUpgrade kernel-zfcpdumpUpgrade kernel-docs-htmlUpgrade dtb-broadcomUpgrade kernel-source-azureUpgrade dtb-qcomUpgrade kselftests-kmp-64kbUpgrade kernel-azure-livepatch-develUpgrade kernel-sourceUpgrade kernel-devel-rtUpgrade kernel-azure-develUpgrade kernel-64kb-livepatch-develUpgrade dtb-alteraUpgrade dtb-hisiliconUpgrade kernel-syms-rtUpgrade kernel-syms-azureUpgrade kernel-default-livepatchUpgrade kernel-debug-livepatch-develUpgrade dtb-amazonUpgrade kernel-rt-livepatchUpgrade kernel-azure-optionalUpgrade dtb-marvellUpgrade kernel-rtUpgrade ocfs2-kmp-rt | Aug 9, 2024 | Feb 27, 2024 |
| Ubuntu | — | Upgrade linux-image-4.4.0-1130-awsUpgrade linux-image-4.4.0-1131-kvmUpgrade linux-image-4.4.0-253-lowlatencyUpgrade linux-image-lowlatencyUpgrade linux-image-virtual-lts-xenialUpgrade linux-image-kvmUpgrade linux-image-4.4.0-1168-awsUpgrade linux-image-generic-lts-xenialUpgrade linux-image-virtualUpgrade linux-image-awsUpgrade linux-image-genericUpgrade linux-image-lowlatency-lts-xenialUpgrade linux-image-4.4.0-253-generic | Apr 22, 2024 | Feb 27, 2024 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Jan 20, 2025 | Feb 27, 2024 |
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