CVE-2023-52835 Information

May 23, 2024 cve

Description

In the Linux kernel the following vulnerability has been resolved:

perf/core: Bail out early if the request AUX area is out of bound

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)

Reference

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