From: Shuai Xue xueshuai@linux.alibaba.com

mainline inclusion from mainline-v6.7-rc1 commit 54aee5f15b83437f23b2b2469bcf21bdd9823916 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RE1F CVE: CVE-2023-52835

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

--------------------------------

When perf-record with a large AUX area, e.g 4GB, it fails with:

#perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1 failed to mmap with 12 (Cannot allocate memory)

and it reveals a WARNING with __alloc_pages():

------------[ cut here ]------------ WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248 Call trace: __alloc_pages+0x1ec/0x248 __kmalloc_large_node+0xc0/0x1f8 __kmalloc_node+0x134/0x1e8 rb_alloc_aux+0xe0/0x298 perf_mmap+0x440/0x660 mmap_region+0x308/0x8a8 do_mmap+0x3c0/0x528 vm_mmap_pgoff+0xf4/0x1b8 ksys_mmap_pgoff+0x18c/0x218 __arm64_sys_mmap+0x38/0x58 invoke_syscall+0x50/0x128 el0_svc_common.constprop.0+0x58/0x188 do_el0_svc+0x34/0x50 el0_svc+0x34/0x108 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x1a4/0x1a8

'rb->aux_pages' allocated by kcalloc() is a pointer array which is used to maintains AUX trace pages. The allocated page for this array is physically contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the size of pointer array crosses the limitation set by MAX_ORDER, it reveals a WARNING.

So bail out early with -ENOMEM if the request AUX area is out of bound, e.g.:

#perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1 failed to mmap with 12 (Cannot allocate memory)

Signed-off-by: Shuai Xue xueshuai@linux.alibaba.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org

Conflicts: kernel/events/ring_buffer.c

Signed-off-by: Luo Gengkun luogengkun2@huawei.com --- kernel/events/ring_buffer.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index a69378d901fa..4e700804a01d 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -638,6 +638,12 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event, } }

+ /* + * kcalloc_node() is unable to allocate buffer if the size is larger + * than: PAGE_SIZE << MAX_ORDER; directly bail out in this case. + */ + if (get_order((unsigned long)nr_pages * sizeof(void *)) > MAX_ORDER) + return -ENOMEM; rb->aux_pages = kcalloc_node(nr_pages, sizeof(void *), GFP_KERNEL, node); if (!rb->aux_pages)