From: Thomas Weißschuh Date: Mon, 13 Oct 2025 10:40:20 +0000 (+0200) Subject: x86/um/vdso: Panic when vDSO can not be allocated X-Git-Tag: v6.19-rc1~104^2~27 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12fe820fae37b95dd55c226346b7ed3fbebac79c;p=thirdparty%2Flinux.git x86/um/vdso: Panic when vDSO can not be allocated The vDSO address is added to the userspace auxiliary vectors even if the vDSO was not allocated. When accessing the page, userspace processes will crash. Enforce that the allocation works. Signed-off-by: Thomas Weißschuh Link: https://patch.msgid.link/20251013-uml-vdso-cleanup-v1-3-a079c7adcc69@weissschuh.net Signed-off-by: Johannes Berg --- diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c index dc8dfb2abd809..51a2b9f2eca95 100644 --- a/arch/x86/um/vdso/vma.c +++ b/arch/x86/um/vdso/vma.c @@ -10,7 +10,6 @@ #include #include -static unsigned int __read_mostly vdso_enabled = 1; unsigned long um_vdso_addr; static struct page *um_vdso; @@ -25,17 +24,11 @@ static int __init init_vdso(void) um_vdso = alloc_page(GFP_KERNEL); if (!um_vdso) - goto oom; + panic("Cannot allocate vdso\n"); copy_page(page_address(um_vdso), vdso_start); return 0; - -oom: - printk(KERN_ERR "Cannot allocate vdso\n"); - vdso_enabled = 0; - - return -ENOMEM; } subsys_initcall(init_vdso); @@ -48,9 +41,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) .pages = &um_vdso, }; - if (!vdso_enabled) - return 0; - if (mmap_write_lock_killable(mm)) return -EINTR;