On Thu, Feb 25, 2021 at 10:22:44AM -0500, George Kennedy wrote: > > > > > > On 2/24/2021 5:37 AM, Mike Rapoport wrote: > > Applied just your latest patch, but same failure. > > I thought there was an earlier comment (which I can't find now) that stated > that memblock_reserve() wouldn't reserve the page, which is what's needed > here. Actually, I think that memblock_reserve() should be just fine, but it seems I'm missing something in address calculation each time. What would happen if you stuck memblock_reserve(0xbe453000, PAGE_SIZE); say, at the beginning of find_ibft_region()? > [ 30.308229] iBFT detected.. > [ 30.308796] > ================================================================== > [ 30.308890] BUG: KASAN: use-after-free in ibft_init+0x134/0xc33 > [ 30.308890] Read of size 4 at addr ffff8880be453004 by task swapper/0/1 > [ 30.308890] > [ 30.308890] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.11.0-f9593a0 #12 > [ 30.308890] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > 0.0.0 02/06/2015 > [ 30.308890] Call Trace: > [ 30.308890] dump_stack+0xdb/0x120 > [ 30.308890] ? ibft_init+0x134/0xc33 > [ 30.308890] print_address_description.constprop.7+0x41/0x60 > [ 30.308890] ? ibft_init+0x134/0xc33 > [ 30.308890] ? ibft_init+0x134/0xc33 > [ 30.308890] kasan_report.cold.10+0x78/0xd1 > [ 30.308890] ? ibft_init+0x134/0xc33 > [ 30.308890] __asan_report_load_n_noabort+0xf/0x20 > [ 30.308890] ibft_init+0x134/0xc33 > [ 30.308890] ? write_comp_data+0x2f/0x90 > [ 30.308890] ? ibft_check_initiator_for+0x159/0x159 > [ 30.308890] ? write_comp_data+0x2f/0x90 > [ 30.308890] ? ibft_check_initiator_for+0x159/0x159 > [ 30.308890] do_one_initcall+0xc4/0x3e0 > [ 30.308890] ? perf_trace_initcall_level+0x3e0/0x3e0 > [ 30.308890] ? unpoison_range+0x14/0x40 > [ 30.308890] ? ____kasan_kmalloc.constprop.5+0x8f/0xc0 > [ 30.308890] ? kernel_init_freeable+0x420/0x652 > [ 30.308890] ? __kasan_kmalloc+0x9/0x10 > [ 30.308890] ? __sanitizer_cov_trace_pc+0x21/0x50 > [ 30.308890] kernel_init_freeable+0x596/0x652 > [ 30.308890] ? console_on_rootfs+0x7d/0x7d > [ 30.308890] ? __sanitizer_cov_trace_pc+0x21/0x50 > [ 30.308890] ? rest_init+0xf0/0xf0 > [ 30.308890] kernel_init+0x16/0x1d0 > [ 30.308890] ? rest_init+0xf0/0xf0 > [ 30.308890] ret_from_fork+0x22/0x30 > [ 30.308890] > [ 30.308890] The buggy address belongs to the page: > [ 30.308890] page:0000000001b7b17c refcount:0 mapcount:0 > mapping:0000000000000000 index:0x1 pfn:0xbe453 > [ 30.308890] flags: 0xfffffc0000000() > [ 30.308890] raw: 000fffffc0000000 ffffea0002ef9788 ffffea0002f91488 > 0000000000000000 > [ 30.308890] raw: 0000000000000001 0000000000000000 00000000ffffffff > 0000000000000000 > [ 30.308890] page dumped because: kasan: bad access detected > [ 30.308890] page_owner tracks the page as freed > [ 30.308890] page last allocated via order 0, migratetype Movable, > gfp_mask 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 204, ts 28121288605 > [ 30.308890] prep_new_page+0xfb/0x140 > [ 30.308890] get_page_from_freelist+0x3503/0x5730 > [ 30.308890] __alloc_pages_nodemask+0x2d8/0x650 > [ 30.308890] alloc_pages_vma+0xe2/0x560 > [ 30.308890] __handle_mm_fault+0x930/0x26c0 > [ 30.308890] handle_mm_fault+0x1f9/0x810 > [ 30.308890] do_user_addr_fault+0x6f7/0xca0 > [ 30.308890] exc_page_fault+0xaf/0x1a0 > [ 30.308890] asm_exc_page_fault+0x1e/0x30 > [ 30.308890] page last free stack trace: > [ 30.308890] free_pcp_prepare+0x122/0x290 > [ 30.308890] free_unref_page_list+0xe6/0x490 > [ 30.308890] release_pages+0x2ed/0x1270 > [ 30.308890] free_pages_and_swap_cache+0x245/0x2e0 > [ 30.308890] tlb_flush_mmu+0x11e/0x680 > [ 30.308890] tlb_finish_mmu+0xa6/0x3e0 > [ 30.308890] exit_mmap+0x2b3/0x540 > [ 30.308890] mmput+0x11d/0x450 > [ 30.308890] do_exit+0xaa6/0x2d40 > [ 30.308890] do_group_exit+0x128/0x340 > [ 30.308890] __x64_sys_exit_group+0x43/0x50 > [ 30.308890] do_syscall_64+0x37/0x50 > [ 30.308890] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [ 30.308890] > [ 30.308890] Memory state around the buggy address: > [ 30.308890] ffff8880be452f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ff ff > [ 30.308890] ffff8880be452f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ff ff > [ 30.308890] >ffff8880be453000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ff ff > [ 30.308890] ^ > [ 30.308890] ffff8880be453080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ff ff > [ 30.308890] ffff8880be453100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ff ff > [ 30.308890] > ================================================================== > > George > -- Sincerely yours, Mike.
