Answer in brief
CVE-2021-47274 records a High severity (CVSS 7.8) vulnerability in tracing: Correct the length check which causes memory corruption. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), linux/linux_kernel (generic), linux/linux_kernel (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), linux/linux_kernel (generic), linux/linux_kernel (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2e584b1a02eeb860e286d39bc408b25ebc5ec844 <edcce01e0e50840a9aa6a70baed21477bdd2c9f9 || >=e46d433754420b4d6513ca389403de88a0910279 <2d598902799886d67947406f26ee8e5fd2ca097f || >=0572fc6a510add9029b113239eaabf4b5bce8ec9 <31ceae385556c37e4d286cb6378696448f566883 || >=a0997a86f5c0085e183ddee5fb72091d584d3d16 <d63f00ec908b3be635ead5d6029cc94246e1f38d || >=7c93d8cff582c459350d6f8906eea6e4cd60d959 <43c32c22254b9328d7abb1c2b0f689dc67838e60 || >=b220c049d5196dd94d992dd2dc8cba1a5e6123bf <b16a249eca2230c2cd66fa1d4b94743bd9b6ef92 || >=b220c049d5196dd94d992dd2dc8cba1a5e6123bf <3e08a9f9760f4a70d633c328a76408e62d6f80a3 || >=4.9.258 <4.9.273 || >=4.14.222 <4.14.237 || >=4.19.177 <4.19.195 || >=5.4.99 <5.4.126 || >=5.10.17 <5.10.44 | edcce01e0e50840a9aa6a70baed21477bdd2c9f9, 2d598902799886d67947406f26ee8e5fd2ca097f, 31ceae385556c37e4d286cb6378696448f566883, d63f00ec908b3be635ead5d6029cc94246e1f38d, 43c32c22254b9328d7abb1c2b0f689dc67838e60, b16a249eca2230c2cd66fa1d4b94743bd9b6ef92, 3e08a9f9760f4a70d633c328a76408e62d6f80a3, 4.9.273, 4.14.237, 4.19.195, 5.4.126, 5.10.44 |
| Linux/Linuxgeneric | 5.11 | Not reported |
| linux/linux_kernelgeneric | >=b220c049d519 <3e08a9f9760f | 3e08a9f9760f |
| linux/linux_kernelgeneric | 5.11 | Not reported |
| linux/linux_kernelgeneric | >=2e584b1a02ee <edcce01e0e50 | edcce01e0e50 |
| linux/linux_kernelgeneric | >=e46d43375442 <2d5989027998 | 2d5989027998 |
| linux/linux_kernelgeneric | >=0572fc6a510a <31ceae385556 | 31ceae385556 |
| linux/linux_kernelgeneric | >=a0997a86f5c0 <d63f00ec908b | d63f00ec908b |
| linux/linux_kernelgeneric | >=7c93d8cff582 <43c32c22254b | 43c32c22254b |
| linux/linux_kernelgeneric | >=b220c049d519 <b16a249eca22 | b16a249eca22 |
Published upstream
May 21, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
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.
Quoted source text, attributed separately from HOL analysis.