CVE-2023-53135

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> riscv: Use READ_ONCE_NOCHECK in imprecise unwinding stack mode<br /> <br /> When CONFIG_FRAME_POINTER is unset, the stack unwinding function<br /> walk_stackframe randomly reads the stack and then, when KASAN is enabled,<br /> it can lead to the following backtrace:<br /> <br /> [ 0.000000] ==================================================================<br /> [ 0.000000] BUG: KASAN: stack-out-of-bounds in walk_stackframe+0xa6/0x11a<br /> [ 0.000000] Read of size 8 at addr ffffffff81807c40 by task swapper/0<br /> [ 0.000000]<br /> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.2.0-12919-g24203e6db61f #43<br /> [ 0.000000] Hardware name: riscv-virtio,qemu (DT)<br /> [ 0.000000] Call Trace:<br /> [ 0.000000] [] walk_stackframe+0x0/0x11a<br /> [ 0.000000] [] init_param_lock+0x26/0x2a<br /> [ 0.000000] [] walk_stackframe+0xa2/0x11a<br /> [ 0.000000] [] dump_stack_lvl+0x22/0x36<br /> [ 0.000000] [] print_report+0x198/0x4a8<br /> [ 0.000000] [] init_param_lock+0x26/0x2a<br /> [ 0.000000] [] walk_stackframe+0xa2/0x11a<br /> [ 0.000000] [] kasan_report+0x9a/0xc8<br /> [ 0.000000] [] walk_stackframe+0xa2/0x11a<br /> [ 0.000000] [] walk_stackframe+0xa2/0x11a<br /> [ 0.000000] [] desc_make_final+0x80/0x84<br /> [ 0.000000] [] stack_trace_save+0x88/0xa6<br /> [ 0.000000] [] filter_irq_stacks+0x72/0x76<br /> [ 0.000000] [] devkmsg_read+0x32a/0x32e<br /> [ 0.000000] [] kasan_save_stack+0x28/0x52<br /> [ 0.000000] [] desc_make_final+0x7c/0x84<br /> [ 0.000000] [] stack_trace_save+0x84/0xa6<br /> [ 0.000000] [] kasan_set_track+0x12/0x20<br /> [ 0.000000] [] __kasan_slab_alloc+0x58/0x5e<br /> [ 0.000000] [] __kmem_cache_create+0x21e/0x39a<br /> [ 0.000000] [] create_boot_cache+0x70/0x9c<br /> [ 0.000000] [] kmem_cache_init+0x6c/0x11e<br /> [ 0.000000] [] mm_init+0xd8/0xfe<br /> [ 0.000000] [] start_kernel+0x190/0x3ca<br /> [ 0.000000]<br /> [ 0.000000] The buggy address belongs to stack of task swapper/0<br /> [ 0.000000] and is located at offset 0 in frame:<br /> [ 0.000000] stack_trace_save+0x0/0xa6<br /> [ 0.000000]<br /> [ 0.000000] This frame has 1 object:<br /> [ 0.000000] [32, 56) &amp;#39;c&amp;#39;<br /> [ 0.000000]<br /> [ 0.000000] The buggy address belongs to the physical page:<br /> [ 0.000000] page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x81a07<br /> [ 0.000000] flags: 0x1000(reserved|zone=0)<br /> [ 0.000000] raw: 0000000000001000 ff600003f1e3d150 ff600003f1e3d150 0000000000000000<br /> [ 0.000000] raw: 0000000000000000 0000000000000000 00000001ffffffff<br /> [ 0.000000] page dumped because: kasan: bad access detected<br /> [ 0.000000]<br /> [ 0.000000] Memory state around the buggy address:<br /> [ 0.000000] ffffffff81807b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00<br /> [ 0.000000] ffffffff81807b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00<br /> [ 0.000000] &gt;ffffffff81807c00: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 f3<br /> [ 0.000000] ^<br /> [ 0.000000] ffffffff81807c80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00<br /> [ 0.000000] ffffffff81807d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00<br /> [ 0.000000] ==================================================================<br /> <br /> Fix that by using READ_ONCE_NOCHECK when reading the stack in imprecise<br /> mode.