From 6c1efdf93e105f8b71692842497e06e06b795f51 Mon Sep 17 00:00:00 2001 From: Tiwei Bie Date: Tue, 11 Mar 2025 08:51:19 +0900 Subject: [PATCH] um: Fix potential integer overflow during physmem setup BugLink: https://bugs.launchpad.net/bugs/2101915 [ Upstream commit a98b7761f697e590ed5d610d87fa12be66f23419 ] This issue happens when the real map size is greater than LONG_MAX, which can be easily triggered on UML/i386. Fixes: fe205bdd1321 ("um: Print minimum physical memory requirement") Signed-off-by: Tiwei Bie Link: https://patch.msgid.link/20240916045950.508910-3-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin CVE-2024-53145 Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- arch/um/kernel/physmem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c index 91485119ae67..4339580f5a4f 100644 --- a/arch/um/kernel/physmem.c +++ b/arch/um/kernel/physmem.c @@ -80,10 +80,10 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end, unsigned long len, unsigned long long highmem) { unsigned long reserve = reserve_end - start; - long map_size = len - reserve; + unsigned long map_size = len - reserve; int err; - if(map_size <= 0) { + if (len <= reserve) { os_warn("Too few physical memory! Needed=%lu, given=%lu\n", reserve, len); exit(1); @@ -94,7 +94,7 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end, err = os_map_memory((void *) reserve_end, physmem_fd, reserve, map_size, 1, 1, 1); if (err < 0) { - os_warn("setup_physmem - mapping %ld bytes of memory at 0x%p " + os_warn("setup_physmem - mapping %lu bytes of memory at 0x%p " "failed - errno = %d\n", map_size, (void *) reserve_end, err); exit(1);