In the Linux kernel, the following vulnerability has been resolved:
tracing: Correct the length check which causes memory corruption
We've suffered from severe kernel crashes due to memory corruption on our production environment, like,
Call Trace: [1640542.554277] general protection fault: 0000 [#1] SMP PTI [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190 [1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286 [1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX: 0000000006e931bf [1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI: ffff9a45ff004300 [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09: 0000000000000000 [1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9a20608d [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15: 696c662f65636976 [1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000) knlGS:0000000000000000 [1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4: 00000000003606e0 [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1640542.566742] Call Trace: [1640542.567009] anon_vma_clone+0x5d/0x170 [1640542.567417] __split_vma+0x91/0x1a0 [1640542.567777] do_munmap+0x2c6/0x320 [1640542.568128] vm_munmap+0x54/0x70 [1640542.569990] __x64_sys_munmap+0x22/0x30 [1640542.572005] do_syscall_64+0x5b/0x1b0 [1640542.573724] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [1640542.575642] RIP: 0033:0x7f45d6e61e27
James Wang has reproduced it stably on the latest 4.19 LTS. After some debugging, we finally proved that it's due to ftrace buffer out-of-bound access using a debug tool as follows: [ 86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000 [ 86.780806] no_context+0xdf/0x3c0 [ 86.784327] __do_page_fault+0x252/0x470 [ 86.788367] do_page_fault+0x32/0x140 [ 86.792145] page_fault+0x1e/0x30 [ 86.795576] strncpy_from_unsafe+0x66/0xb0 [ 86.799789] fetch_memory_string+0x25/0x40 [ 86.804002] fetch_deref_string+0x51/0x60 [ 86.808134] kprobe_trace_func+0x32d/0x3a0 [ 86.812347] kprobe_dispatcher+0x45/0x50 [ 86.816385] kprobe_ftrace_handler+0x90/0xf0 [ 86.820779] ftrace_ops_assist_func+0xa1/0x140 [ 86.825340] 0xffffffffc00750bf [ 86.828603] do_sys_open+0x5/0x1f0 [ 86.832124] do_syscall_64+0x5b/0x1b0 [ 86.835900] entry_SYSCALL_64_after_hwframe+0x44/0xa9
commit b220c049d519 ("tracing: Check length before giving out the filter buffer") adds length check to protect trace data overflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent overflow entirely, the length check should also take the sizeof entry->array[0] into account, since this array[0] is filled the length of trace data and occupy addtional space and risk overflow.
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-4.14.238-182.421Upgrade perf-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade python-perf-debuginfoUpgrade kernel-headersUpgrade perfUpgrade kernel-debuginfoUpgrade kernel-tools-develUpgrade bpftoolUpgrade kernel-tools-debuginfoUpgrade kernel-toolsUpgrade kernelUpgrade python-perfUpgrade bpftool-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-devel | Nov 12, 2024 | May 21, 2024 |
| Debian | — | Upgrade linux | Jul 30, 2024 | May 21, 2024 |
| Huawei Euleros 2_0_sp8 | — | Upgrade kernel-toolsUpgrade kernel-headersUpgrade python-perfUpgrade kernel-develUpgrade kernel-tools-libsUpgrade kernelUpgrade perfUpgrade bpftoolUpgrade python3-perf | Jan 21, 2025 | May 21, 2024 |
| Huawei Euleros 2_0_sp9 | — | Upgrade kernelUpgrade kernel-tools-libsUpgrade python3-perfUpgrade kernel-tools | Jul 17, 2024 | May 21, 2024 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | May 21, 2024 |
| Suse | — | Upgrade kernel-default-develUpgrade kernel-devel-azureUpgrade kernel-macrosUpgrade kernel-source-azureUpgrade kernel-azure-baseUpgrade kernel-obs-buildUpgrade kernel-defaultUpgrade kernel-syms-azureUpgrade kernel-azureUpgrade kernel-default-manUpgrade kernel-azure-develUpgrade kernel-preemptUpgrade kernel-default-extraUpgrade reiserfs-kmp-defaultUpgrade kernel-symsUpgrade kernel-zfcpdumpUpgrade kernel-64kbUpgrade kernel-default-baseUpgrade kernel-develUpgrade kernel-docsUpgrade kernel-64kb-develUpgrade kernel-preempt-develUpgrade kernel-source | Aug 9, 2024 | May 21, 2024 |
| Ubuntu | — | Upgrade linux-gkeopUpgrade linux-hweUpgrade linux-oracleUpgrade linux-kvmUpgrade linux-gcp-fipsUpgrade linux-hwe-5.4Upgrade linux-azure-5.4Upgrade linux-gcp-5.4Upgrade linux-gcp-4.15Upgrade linux-aws-fipsUpgrade linux-azure-4.15Upgrade linux-azure-fipsUpgrade linux-azureUpgrade linux-raspiUpgrade linux-bluefieldUpgrade linux-raspi-5.4Upgrade linux-aws-5.4Upgrade linux-oracle-5.4Upgrade linux-fipsUpgrade linuxUpgrade linux-awsUpgrade linux-gcpUpgrade linux-aws-hwe | Nov 19, 2024 | May 21, 2024 |
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