This is a note to let you know that I've just added the patch titled
x86/kasan: Panic if there is not enough memory to boot
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86-kasan-panic-if-there-is-not-enough-memory-to-boot.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 0d39e2669d7b0fefd2d8f9e7868ae669b364d9ba Mon Sep 17 00:00:00 2001
From: Andrey Ryabinin aryabinin@virtuozzo.com Date: Wed, 10 Jan 2018 18:36:02 +0300 Subject: x86/kasan: Panic if there is not enough memory to boot
From: Andrey Ryabinin aryabinin@virtuozzo.com
commit 0d39e2669d7b0fefd2d8f9e7868ae669b364d9ba upstream.
Currently KASAN doesn't panic in case it don't have enough memory to boot. Instead, it crashes in some random place:
kernel BUG at arch/x86/mm/physaddr.c:27!
RIP: 0010:__phys_addr+0x268/0x276 Call Trace: kasan_populate_shadow+0x3f2/0x497 kasan_init+0x12e/0x2b2 setup_arch+0x2825/0x2a2c start_kernel+0xc8/0x15f4 x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x72/0x75 secondary_startup_64+0xa5/0xb0
Use memblock_virt_alloc_try_nid() for allocations without failure fallback. It will panic with an out of memory message.
Reported-by: kernel test robot xiaolong.ye@intel.com Signed-off-by: Andrey Ryabinin aryabinin@virtuozzo.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Dmitry Vyukov dvyukov@google.com Cc: kasan-dev@googlegroups.com Cc: Alexander Potapenko glider@google.com Cc: lkp@01.org Link: https://lkml.kernel.org/r/20180110153602.18919-1-aryabinin@virtuozzo.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/mm/kasan_init_64.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
--- a/arch/x86/mm/kasan_init_64.c +++ b/arch/x86/mm/kasan_init_64.c @@ -21,10 +21,14 @@ extern struct range pfn_mapped[E820_MAX_
static p4d_t tmp_p4d_table[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE);
-static __init void *early_alloc(size_t size, int nid) +static __init void *early_alloc(size_t size, int nid, bool panic) { - return memblock_virt_alloc_try_nid_nopanic(size, size, - __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); + if (panic) + return memblock_virt_alloc_try_nid(size, size, + __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); + else + return memblock_virt_alloc_try_nid_nopanic(size, size, + __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); }
static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr, @@ -38,14 +42,14 @@ static void __init kasan_populate_pmd(pm if (boot_cpu_has(X86_FEATURE_PSE) && ((end - addr) == PMD_SIZE) && IS_ALIGNED(addr, PMD_SIZE)) { - p = early_alloc(PMD_SIZE, nid); + p = early_alloc(PMD_SIZE, nid, false); if (p && pmd_set_huge(pmd, __pa(p), PAGE_KERNEL)) return; else if (p) memblock_free(__pa(p), PMD_SIZE); }
- p = early_alloc(PAGE_SIZE, nid); + p = early_alloc(PAGE_SIZE, nid, true); pmd_populate_kernel(&init_mm, pmd, p); }
@@ -57,7 +61,7 @@ static void __init kasan_populate_pmd(pm if (!pte_none(*pte)) continue;
- p = early_alloc(PAGE_SIZE, nid); + p = early_alloc(PAGE_SIZE, nid, true); entry = pfn_pte(PFN_DOWN(__pa(p)), PAGE_KERNEL); set_pte_at(&init_mm, addr, pte, entry); } while (pte++, addr += PAGE_SIZE, addr != end); @@ -75,14 +79,14 @@ static void __init kasan_populate_pud(pu if (boot_cpu_has(X86_FEATURE_GBPAGES) && ((end - addr) == PUD_SIZE) && IS_ALIGNED(addr, PUD_SIZE)) { - p = early_alloc(PUD_SIZE, nid); + p = early_alloc(PUD_SIZE, nid, false); if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL)) return; else if (p) memblock_free(__pa(p), PUD_SIZE); }
- p = early_alloc(PAGE_SIZE, nid); + p = early_alloc(PAGE_SIZE, nid, true); pud_populate(&init_mm, pud, p); }
@@ -101,7 +105,7 @@ static void __init kasan_populate_p4d(p4 unsigned long next;
if (p4d_none(*p4d)) { - void *p = early_alloc(PAGE_SIZE, nid); + void *p = early_alloc(PAGE_SIZE, nid, true);
p4d_populate(&init_mm, p4d, p); } @@ -122,7 +126,7 @@ static void __init kasan_populate_pgd(pg unsigned long next;
if (pgd_none(*pgd)) { - p = early_alloc(PAGE_SIZE, nid); + p = early_alloc(PAGE_SIZE, nid, true); pgd_populate(&init_mm, pgd, p); }
Patches currently in stable-queue which might be from aryabinin@virtuozzo.com are
queue-4.14/x86-kasan-panic-if-there-is-not-enough-memory-to-boot.patch