[PATCH RESEND 2/3] x86/vdso: Use kstrtouint() to validate vdso32= boot parameter
COLD32d
From: Thorsten Blum <blum@kernel.org>
Date: 2026-08-31 10:18:11
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Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
Replace the deprecated simple_strtoul() with kstrtouint() when parsing the vdso32= boot parameter and its X86_32 vdso= alias. simple_strtoul() accepts partial input and silently converts invalid input to 0. Use kstrtouint() for strict input validation instead and reject malformed input. Accept only 0 and 1; warn and disable vDSO support otherwise. kstrtouint() converts the input string directly to an unsigned int, avoiding an implicit conversion when assigning to vdso32_enabled. Update the vdso32= handler comment to reflect the supported values. Signed-off-by: Thorsten Blum <blum@kernel.org> --- arch/x86/entry/vdso/vdso32-setup.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32-setup.c b/arch/x86/entry/vdso/vdso32-setup.c
index 8894013eea1d..5f3e548ebf19 100644
--- a/arch/x86/entry/vdso/vdso32-setup.c
+++ b/arch/x86/entry/vdso/vdso32-setup.c@@ -30,10 +30,8 @@ unsigned int __read_mostly vdso32_enabled = VDSO_DEFAULT; static int __init vdso32_setup(char *s) { - vdso32_enabled = simple_strtoul(s, NULL, 0); - - if (vdso32_enabled > 1) { - pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n"); + if (kstrtouint(s, 0, &vdso32_enabled) || vdso32_enabled > 1) { + pr_warn("vdso32= values other than 0 and 1 are invalid; vdso disabled\n"); vdso32_enabled = 0; }
@@ -41,9 +39,9 @@ static int __init vdso32_setup(char *s) } /* - * For consistency, the argument vdso32=[012] affects the 32-bit vDSO + * For consistency, the argument vdso32=[01] affects the 32-bit vDSO * behavior on both 64-bit and 32-bit kernels. - * On 32-bit kernels, vdso=[012] means the same thing. + * On 32-bit kernels, vdso=[01] means the same thing. */ __setup("vdso32=", vdso32_setup);