{ "threat_severity" : "Low", "public_date" : "2025-07-10T00:00:00Z", "bugzilla" : { "description" : "kernel: bpf: Do not include stack ptr register in precision backtracking bookkeeping", "id" : "2379178", "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2379178" }, "cvss3" : { "cvss3_base_score" : "3.3", "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L", "status" : "verified" }, "cwe" : "CWE-824", "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nbpf: Do not include stack ptr register in precision backtracking bookkeeping\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\n01 48 c7 c7 00 58 30 84 e8 c4 06 a5 ff <0f> 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] \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...\nFurther analysis shows the warning is at line 4302 as below:\n4294 /* static subprog call instruction, which\n4295 * means that we are exiting current subprog,\n4296 * so only r1-r5 could be still requested as\n4297 * precise, r0 and r6-r10 or any stack slot in\n4298 * the current frame should be zero by now\n4299 */\n4300 if (bt_reg_mask(bt) & ~BPF_REGMASK_ARGS) {\n4301 verbose(env, \"BUG regs %x\\n\", bt_reg_mask(bt));\n4302 WARN_ONCE(1, \"verifier backtracking bug\");\n4303 return -EFAULT;\n4304 }\nWith the below test (also in the next patch):\n__used __naked static void __bpf_jmp_r10(void)\n{\nasm volatile (\n\"r2 = 2314885393468386424 ll;\"\n\"goto +0;\"\n\"if r2 <= r10 goto +3;\"\n\"if r1 >= -1835016 goto +0;\"\n\"if r2 <= 8 goto +0;\"\n\"if r3 <= 0 goto +0;\"\n\"exit;\"\n::: __clobber_all);\n}\nSEC(\"?raw_tp\")\n__naked void bpf_jmp_r10(void)\n{\nasm volatile (\n\"r3 = 0 ll;\"\n\"call __bpf_jmp_r10;\"\n\"r0 = 0;\"\n\"exit;\"\n::: __clobber_all);\n}\nThe following is the verifier failure log:\n0: (18) r3 = 0x0 ; R3_w=0\n2: (85) call pc+2\ncaller:\nR10=fp0\ncallee:\nframe1: R1=ctx() R3_w=0 R10=fp0\n5: frame1: R1=ctx() R3_w=0 R10=fp0\n; asm volatile (\" \\ @ verifier_precision.c:184\n5: (18) r2 = 0x20202000256c6c78 ; frame1: R2_w=0x20202000256c6c78\n7: (05) goto pc+0\n8: (bd) if r2 <= r10 goto pc+3 ; frame1: R2_w=0x20202000256c6c78 R10=fp0\n9: (35) if r1 >= 0xffe3fff8 goto pc+0 ; frame1: R1=ctx()\n10: (b5) if r2 <= 0x8 goto pc+0\nmark_precise: frame1: last_idx 10 first_idx 0 subseq_idx -1\nmark_precise: frame1: regs=r2 stack= before 9: (35) if r1 >= 0xffe3fff8 goto pc+0\nmark_precise: frame1: regs=r2 stack= before 8: (bd) if r2 <= r10 goto pc+3\nmark_preci\n---truncated---" ], "affected_release" : [ { "product_name" : "Red Hat Enterprise Linux 10", "release_date" : "2026-05-19T00:00:00Z", "advisory" : "RHSA-2026:18134", "cpe" : "cpe:/o:redhat:enterprise_linux:10.2", "package" : "kernel-0:6.12.0-211.7.1.el10_2" }, { "product_name" : "Red Hat Enterprise Linux 9", "release_date" : "2026-05-19T00:00:00Z", "advisory" : "RHSA-2026:18587", "cpe" : "cpe:/a:redhat:enterprise_linux:9", "package" : "kernel-0:5.14.0-687.5.1.el9_8" }, { "product_name" : "Red Hat Enterprise Linux 9", "release_date" : "2026-05-19T00:00:00Z", "advisory" : "RHSA-2026:18587", "cpe" : "cpe:/o:redhat:enterprise_linux:9", "package" : "kernel-0:5.14.0-687.5.1.el9_8" } ], "package_state" : [ { "product_name" : "Red Hat Enterprise Linux 6", "fix_state" : "Not affected", "package_name" : "kernel", "cpe" : "cpe:/o:redhat:enterprise_linux:6" }, { "product_name" : "Red Hat Enterprise Linux 7", "fix_state" : "Not affected", "package_name" : "kernel", "cpe" : "cpe:/o:redhat:enterprise_linux:7" }, { "product_name" : "Red Hat Enterprise Linux 7", "fix_state" : "Not affected", "package_name" : "kernel-rt", "cpe" : "cpe:/o:redhat:enterprise_linux:7" }, { "product_name" : "Red Hat Enterprise Linux 8", "fix_state" : "Not affected", "package_name" : "kernel", "cpe" : "cpe:/o:redhat:enterprise_linux:8" }, { "product_name" : "Red Hat Enterprise Linux 8", "fix_state" : "Not affected", "package_name" : "kernel-rt", "cpe" : "cpe:/o:redhat:enterprise_linux:8" }, { "product_name" : "Red Hat Enterprise Linux 9", "fix_state" : "Fix deferred", "package_name" : "kernel-rt", "cpe" : "cpe:/o:redhat:enterprise_linux:9" } ], "references" : [ "https://www.cve.org/CVERecord?id=CVE-2025-38279\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-38279\nhttps://lore.kernel.org/linux-cve-announce/2025071009-CVE-2025-38279-af9f@gregkh/T" ], "name" : "CVE-2025-38279", "csaw" : false }