ghsa-f7v2-pww5-gxcf
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
bpf: Do not include stack ptr register in precision backtracking bookkeeping
Yi Lai reported an issue ([1]) where the following warning appears in kernel dmesg: [ 60.643604] verifier backtracking bug [ 60.643635] WARNING: CPU: 10 PID: 2315 at kernel/bpf/verifier.c:4302 __mark_chain_precision+0x3a6c/0x3e10 [ 60.648428] Modules linked in: bpf_testmod(OE) [ 60.650471] CPU: 10 UID: 0 PID: 2315 Comm: test_progs Tainted: G OE 6.15.0-rc4-gef11287f8289-dirty #327 PREEMPT(full) [ 60.654385] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 60.656682] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 60.660475] RIP: 0010:__mark_chain_precision+0x3a6c/0x3e10 [ 60.662814] Code: 5a 30 84 89 ea e8 c4 d9 01 00 80 3d 3e 7d d8 04 00 0f 85 60 fa ff ff c6 05 31 7d d8 04 01 48 c7 c7 00 58 30 84 e8 c4 06 a5 ff <0f> 0b e9 46 fa ff ff 48 ... [ 60.668720] RSP: 0018:ffff888116cc7298 EFLAGS: 00010246 [ 60.671075] RAX: 54d70e82dfd31900 RBX: ffff888115b65e20 RCX: 0000000000000000 [ 60.673659] RDX: 0000000000000001 RSI: 0000000000000004 RDI: 00000000ffffffff [ 60.676241] RBP: 0000000000000400 R08: ffff8881f6f23bd3 R09: 1ffff1103ede477a [ 60.678787] R10: dffffc0000000000 R11: ffffed103ede477b R12: ffff888115b60ae8 [ 60.681420] R13: 1ffff11022b6cbc4 R14: 00000000fffffff2 R15: 0000000000000001 [ 60.684030] FS: 00007fc2aedd80c0(0000) GS:ffff88826fa8a000(0000) knlGS:0000000000000000 [ 60.686837] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 60.689027] CR2: 000056325369e000 CR3: 000000011088b002 CR4: 0000000000370ef0 [ 60.691623] Call Trace: [ 60.692821] [ 60.693960] ? __pfx_verbose+0x10/0x10 [ 60.695656] ? __pfx_disasm_kfunc_name+0x10/0x10 [ 60.697495] check_cond_jmp_op+0x16f7/0x39b0 [ 60.699237] do_check+0x58fa/0xab10 ...
Further analysis shows the warning is at line 4302 as below:
4294 / static subprog call instruction, which 4295 * means that we are exiting current subprog, 4296 * so only r1-r5 could be still requested as 4297 * precise, r0 and r6-r10 or any stack slot in 4298 * the current frame should be zero by now 4299 / 4300 if (bt_reg_mask(bt) & ~BPF_REGMASK_ARGS) { 4301 verbose(env, "BUG regs %x\n", bt_reg_mask(bt)); 4302 WARN_ONCE(1, "verifier backtracking bug"); 4303 return -EFAULT; 4304 }
With the below test (also in the next patch): __used __naked static void __bpf_jmp_r10(void) { asm volatile ( "r2 = 2314885393468386424 ll;" "goto +0;" "if r2 <= r10 goto +3;" "if r1 >= -1835016 goto +0;" "if r2 <= 8 goto +0;" "if r3 <= 0 goto +0;" "exit;" ::: __clobber_all); }
SEC("?raw_tp") __naked void bpf_jmp_r10(void) { asm volatile ( "r3 = 0 ll;" "call __bpf_jmp_r10;" "r0 = 0;" "exit;" ::: __clobber_all); }
The following is the verifier failure log: 0: (18) r3 = 0x0 ; R3_w=0 2: (85) call pc+2 caller: R10=fp0 callee: frame1: R1=ctx() R3_w=0 R10=fp0 5: frame1: R1=ctx() R3_w=0 R10=fp0 ; asm volatile (" \ @ verifier_precision.c:184 5: (18) r2 = 0x20202000256c6c78 ; frame1: R2_w=0x20202000256c6c78 7: (05) goto pc+0 8: (bd) if r2 <= r10 goto pc+3 ; frame1: R2_w=0x20202000256c6c78 R10=fp0 9: (35) if r1 >= 0xffe3fff8 goto pc+0 ; frame1: R1=ctx() 10: (b5) if r2 <= 0x8 goto pc+0 mark_precise: frame1: last_idx 10 first_idx 0 subseq_idx -1 mark_precise: frame1: regs=r2 stack= before 9: (35) if r1 >= 0xffe3fff8 goto pc+0 mark_precise: frame1: regs=r2 stack= before 8: (bd) if r2 <= r10 goto pc+3 mark_preci ---truncated---
{
"affected": [],
"aliases": [
"CVE-2025-38279"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-07-10T08:15:26Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Do not include stack ptr register in precision backtracking bookkeeping\n\nYi Lai reported an issue ([1]) where the following warning appears\nin kernel dmesg:\n [ 60.643604] verifier backtracking bug\n [ 60.643635] WARNING: CPU: 10 PID: 2315 at kernel/bpf/verifier.c:4302 __mark_chain_precision+0x3a6c/0x3e10\n [ 60.648428] Modules linked in: bpf_testmod(OE)\n [ 60.650471] CPU: 10 UID: 0 PID: 2315 Comm: test_progs Tainted: G OE 6.15.0-rc4-gef11287f8289-dirty #327 PREEMPT(full)\n [ 60.654385] Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n [ 60.656682] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014\n [ 60.660475] RIP: 0010:__mark_chain_precision+0x3a6c/0x3e10\n [ 60.662814] Code: 5a 30 84 89 ea e8 c4 d9 01 00 80 3d 3e 7d d8 04 00 0f 85 60 fa ff ff c6 05 31 7d d8 04\n 01 48 c7 c7 00 58 30 84 e8 c4 06 a5 ff \u003c0f\u003e 0b e9 46 fa ff ff 48 ...\n [ 60.668720] RSP: 0018:ffff888116cc7298 EFLAGS: 00010246\n [ 60.671075] RAX: 54d70e82dfd31900 RBX: ffff888115b65e20 RCX: 0000000000000000\n [ 60.673659] RDX: 0000000000000001 RSI: 0000000000000004 RDI: 00000000ffffffff\n [ 60.676241] RBP: 0000000000000400 R08: ffff8881f6f23bd3 R09: 1ffff1103ede477a\n [ 60.678787] R10: dffffc0000000000 R11: ffffed103ede477b R12: ffff888115b60ae8\n [ 60.681420] R13: 1ffff11022b6cbc4 R14: 00000000fffffff2 R15: 0000000000000001\n [ 60.684030] FS: 00007fc2aedd80c0(0000) GS:ffff88826fa8a000(0000) knlGS:0000000000000000\n [ 60.686837] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n [ 60.689027] CR2: 000056325369e000 CR3: 000000011088b002 CR4: 0000000000370ef0\n [ 60.691623] Call Trace:\n [ 60.692821] \u003cTASK\u003e\n [ 60.693960] ? __pfx_verbose+0x10/0x10\n [ 60.695656] ? __pfx_disasm_kfunc_name+0x10/0x10\n [ 60.697495] check_cond_jmp_op+0x16f7/0x39b0\n [ 60.699237] do_check+0x58fa/0xab10\n ...\n\nFurther analysis shows the warning is at line 4302 as below:\n\n 4294 /* static subprog call instruction, which\n 4295 * means that we are exiting current subprog,\n 4296 * so only r1-r5 could be still requested as\n 4297 * precise, r0 and r6-r10 or any stack slot in\n 4298 * the current frame should be zero by now\n 4299 */\n 4300 if (bt_reg_mask(bt) \u0026 ~BPF_REGMASK_ARGS) {\n 4301 verbose(env, \"BUG regs %x\\n\", bt_reg_mask(bt));\n 4302 WARN_ONCE(1, \"verifier backtracking bug\");\n 4303 return -EFAULT;\n 4304 }\n\nWith the below test (also in the next patch):\n __used __naked static void __bpf_jmp_r10(void)\n {\n\tasm volatile (\n\t\"r2 = 2314885393468386424 ll;\"\n\t\"goto +0;\"\n\t\"if r2 \u003c= r10 goto +3;\"\n\t\"if r1 \u003e= -1835016 goto +0;\"\n\t\"if r2 \u003c= 8 goto +0;\"\n\t\"if r3 \u003c= 0 goto +0;\"\n\t\"exit;\"\n\t::: __clobber_all);\n }\n\n SEC(\"?raw_tp\")\n __naked void bpf_jmp_r10(void)\n {\n\tasm volatile (\n\t\"r3 = 0 ll;\"\n\t\"call __bpf_jmp_r10;\"\n\t\"r0 = 0;\"\n\t\"exit;\"\n\t::: __clobber_all);\n }\n\nThe following is the verifier failure log:\n 0: (18) r3 = 0x0 ; R3_w=0\n 2: (85) call pc+2\n caller:\n R10=fp0\n callee:\n frame1: R1=ctx() R3_w=0 R10=fp0\n 5: frame1: R1=ctx() R3_w=0 R10=fp0\n ; asm volatile (\" \\ @ verifier_precision.c:184\n 5: (18) r2 = 0x20202000256c6c78 ; frame1: R2_w=0x20202000256c6c78\n 7: (05) goto pc+0\n 8: (bd) if r2 \u003c= r10 goto pc+3 ; frame1: R2_w=0x20202000256c6c78 R10=fp0\n 9: (35) if r1 \u003e= 0xffe3fff8 goto pc+0 ; frame1: R1=ctx()\n 10: (b5) if r2 \u003c= 0x8 goto pc+0\n mark_precise: frame1: last_idx 10 first_idx 0 subseq_idx -1\n mark_precise: frame1: regs=r2 stack= before 9: (35) if r1 \u003e= 0xffe3fff8 goto pc+0\n mark_precise: frame1: regs=r2 stack= before 8: (bd) if r2 \u003c= r10 goto pc+3\n mark_preci\n---truncated---",
"id": "GHSA-f7v2-pww5-gxcf",
"modified": "2025-07-10T15:31:26Z",
"published": "2025-07-10T09:32:29Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38279"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4265682c29c92f52c0da6fad5a79b5801462c8de"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ac49b7560b4b08b1e4043a29214cc7ad77644c00"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e2d2115e56c4a02377189bfc3a9a7933552a7b0f"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
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- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.