From: Tom Lendacky <thomas.lendacky@amd.com> stable inclusion from stable-v6.6.92 commit 7bcd29181bab8d508d2adfdbb132de8b1e088698 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC992A CVE: CVE-2025-37960 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit da8bf5daa5e55a6af2b285ecda460d6454712ff4 upstream. When increasing the array size in memblock_double_array() and the slab is not yet available, a call to memblock_find_in_range() is used to reserve/allocate memory. However, the range returned may not have been accepted, which can result in a crash when booting an SNP guest: RIP: 0010:memcpy_orig+0x68/0x130 Code: ... RSP: 0000:ffffffff9cc03ce8 EFLAGS: 00010006 RAX: ff11001ff83e5000 RBX: 0000000000000000 RCX: fffffffffffff000 RDX: 0000000000000bc0 RSI: ffffffff9dba8860 RDI: ff11001ff83e5c00 RBP: 0000000000002000 R08: 0000000000000000 R09: 0000000000002000 R10: 000000207fffe000 R11: 0000040000000000 R12: ffffffff9d06ef78 R13: ff11001ff83e5000 R14: ffffffff9dba7c60 R15: 0000000000000c00 memblock_double_array+0xff/0x310 memblock_add_range+0x1fb/0x2f0 memblock_reserve+0x4f/0xa0 memblock_alloc_range_nid+0xac/0x130 memblock_alloc_internal+0x53/0xc0 memblock_alloc_try_nid+0x3d/0xa0 swiotlb_init_remap+0x149/0x2f0 mem_init+0xb/0xb0 mm_core_init+0x8f/0x350 start_kernel+0x17e/0x5d0 x86_64_start_reservations+0x14/0x30 x86_64_start_kernel+0x92/0xa0 secondary_startup_64_no_verify+0x194/0x19b Mitigate this by calling accept_memory() on the memory range returned before the slab is available. Prior to v6.12, the accept_memory() interface used a 'start' and 'end' parameter instead of 'start' and 'size', therefore the accept_memory() call must be adjusted to specify 'start + size' for 'end' when applying to kernels prior to v6.12. Cc: stable@vger.kernel.org # see patch description, needs adjustments for <= 6.11 Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/da1ac73bf4ded761e21b4e4bb5178382a580cd73.174672505... Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> --- mm/memblock.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/mm/memblock.c b/mm/memblock.c index 57f7ef7791e0..dca1c491dcdb 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -460,7 +460,14 @@ static int __init_memblock memblock_double_array(struct memblock_type *type, min(new_area_start, memblock.current_limit), new_alloc_size, PAGE_SIZE); - new_array = addr ? __va(addr) : NULL; + if (addr) { + /* The memory may not have been accepted, yet. */ + accept_memory(addr, addr + new_alloc_size); + + new_array = __va(addr); + } else { + new_array = NULL; + } } if (!addr) { pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n", -- 2.43.0