From 5f8719945244dd65b5fa06195f4600db62581610 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 5 May 2026 10:06:53 +0200 Subject: [PATCH] x86/xen: Fix a potential problem in xen_e820_resolve_conflicts() When fixing a conflict in xen_e820_resolve_conflicts(), the loop over the E820 map entries needs to be restarted, as the E820 map will have been modified by the fix. Otherwise entries might be skipped by accident. Fixes: be35d91c8880 ("xen: tolerate ACPI NVS memory overlapping with Xen allocated memory") Signed-off-by: Juergen Gross Signed-off-by: Ingo Molnar Cc: xen-devel@lists.xenproject.org Link: https://patch.msgid.link/20260505080653.197775-1-jgross@suse.com --- arch/x86/xen/setup.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index ac8021c3a997e..bb95a05259b89 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -695,17 +695,22 @@ static void __init xen_e820_resolve_conflicts(phys_addr_t start, return; end = start + size; - entry = xen_e820_table.entries; + mapcnt = 0; - for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { + while (mapcnt < xen_e820_table.nr_entries) { + entry = xen_e820_table.entries + mapcnt; if (entry->addr >= end) return; if (entry->addr + entry->size > start && - entry->type == E820_TYPE_NVS) + entry->type == E820_TYPE_NVS) { xen_e820_swap_entry_with_ram(entry); + /* E820 map has been changed, restart loop! */ + mapcnt = 0; + continue; + } - entry++; + mapcnt++; } } -- 2.47.3