| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-22069: riscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| riscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler |
| |
| Naresh Kamboju reported a "Bad frame pointer" kernel warning while |
| running LTP trace ftrace_stress_test.sh in riscv. We can reproduce the |
| same issue with the following command: |
| |
| ``` |
| $ cd /sys/kernel/debug/tracing |
| $ echo 'f:myprobe do_nanosleep%return args1=$retval' > dynamic_events |
| $ echo 1 > events/fprobes/enable |
| $ echo 1 > tracing_on |
| $ sleep 1 |
| ``` |
| |
| And we can get the following kernel warning: |
| |
| [ 127.692888] ------------[ cut here ]------------ |
| [ 127.693755] Bad frame pointer: expected ff2000000065be50, received ba34c141e9594000 |
| [ 127.693755] from func do_nanosleep return to ffffffff800ccb16 |
| [ 127.698699] WARNING: CPU: 1 PID: 129 at kernel/trace/fgraph.c:755 ftrace_return_to_handler+0x1b2/0x1be |
| [ 127.699894] Modules linked in: |
| [ 127.700908] CPU: 1 UID: 0 PID: 129 Comm: sleep Not tainted 6.14.0-rc3-g0ab191c74642 #32 |
| [ 127.701453] Hardware name: riscv-virtio,qemu (DT) |
| [ 127.701859] epc : ftrace_return_to_handler+0x1b2/0x1be |
| [ 127.702032] ra : ftrace_return_to_handler+0x1b2/0x1be |
| [ 127.702151] epc : ffffffff8013b5e0 ra : ffffffff8013b5e0 sp : ff2000000065bd10 |
| [ 127.702221] gp : ffffffff819c12f8 tp : ff60000080853100 t0 : 6e00000000000000 |
| [ 127.702284] t1 : 0000000000000020 t2 : 6e7566206d6f7266 s0 : ff2000000065bd80 |
| [ 127.702346] s1 : ff60000081262000 a0 : 000000000000007b a1 : ffffffff81894f20 |
| [ 127.702408] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : 0000000000000000 |
| [ 127.702470] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 |
| [ 127.702530] s2 : ba34c141e9594000 s3 : 0000000000000000 s4 : ff2000000065bdd0 |
| [ 127.702591] s5 : 00007fff8adcf400 s6 : 000055556dc1d8c0 s7 : 0000000000000068 |
| [ 127.702651] s8 : 00007fff8adf5d10 s9 : 000000000000006d s10: 0000000000000001 |
| [ 127.702710] s11: 00005555737377c8 t3 : ffffffff819d899e t4 : ffffffff819d899e |
| [ 127.702769] t5 : ffffffff819d89a0 t6 : ff2000000065bb18 |
| [ 127.702826] status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003 |
| [ 127.703292] [<ffffffff8013b5e0>] ftrace_return_to_handler+0x1b2/0x1be |
| [ 127.703760] [<ffffffff80017bce>] return_to_handler+0x16/0x26 |
| [ 127.704009] [<ffffffff80017bb8>] return_to_handler+0x0/0x26 |
| [ 127.704057] [<ffffffff800d3352>] common_nsleep+0x42/0x54 |
| [ 127.704117] [<ffffffff800d44a2>] __riscv_sys_clock_nanosleep+0xba/0x10a |
| [ 127.704176] [<ffffffff80901c56>] do_trap_ecall_u+0x188/0x218 |
| [ 127.704295] [<ffffffff8090cc3e>] handle_exception+0x14a/0x156 |
| [ 127.705436] ---[ end trace 0000000000000000 ]--- |
| |
| The reason is that the stack layout for constructing argument for the |
| ftrace_return_to_handler in the return_to_handler does not match the |
| __arch_ftrace_regs structure of riscv, leading to unexpected results. |
| |
| The Linux kernel CVE team has assigned CVE-2025-22069 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.14 with commit a3ed4157b7d89800a0008de0c9e46a438a5c3745 and fixed in 6.14.2 with commit 78b39c587b8f6c69140177108f9c08a75b1c7c37 |
| Issue introduced in 6.14 with commit a3ed4157b7d89800a0008de0c9e46a438a5c3745 and fixed in 6.15 with commit 67a5ba8f742f247bc83e46dd2313c142b1383276 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-22069 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| arch/riscv/kernel/mcount.S |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/78b39c587b8f6c69140177108f9c08a75b1c7c37 |
| https://git.kernel.org/stable/c/67a5ba8f742f247bc83e46dd2313c142b1383276 |
