CVE-2025-38279
Linux BPF verifier stack ptr register vulnerability
Description
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] <TASK> [ 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---
INFO
Published Date :
July 10, 2025, 8:15 a.m.
Last Modified :
July 10, 2025, 3:15 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-38279.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-38279 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-38279 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 10, 2025
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/4265682c29c92f52c0da6fad5a79b5801462c8de -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 10, 2025
Action Type Old Value New Value Added Description 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] <TASK> [ 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--- Added Reference https://git.kernel.org/stable/c/ac49b7560b4b08b1e4043a29214cc7ad77644c00 Added Reference https://git.kernel.org/stable/c/e2d2115e56c4a02377189bfc3a9a7933552a7b0f
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-38279 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-38279
weaknesses.