================================================================== BUG: KASAN: use-after-free in strcmp+0x66/0xa0 lib/string.c:346 Read of size 1 at addr ffff8881421af0f4 by task syz-executor.2/29697 CPU: 0 PID: 29697 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00329-g42964a18f81c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 print_address_description+0x65/0x3a0 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report+0x19a/0x1f0 mm/kasan/report.c:459 strcmp+0x66/0xa0 lib/string.c:346 replace_vma_anon_name mm/madvise.c:141 [inline] madvise_update_vma+0x768/0xa90 mm/madvise.c:212 madvise_vma_behavior mm/madvise.c:1043 [inline] madvise_walk_vmas mm/madvise.c:1207 [inline] do_madvise+0xcdf/0x13f0 mm/madvise.c:1385 __do_sys_madvise mm/madvise.c:1398 [inline] __se_sys_madvise mm/madvise.c:1396 [inline] __x64_sys_madvise+0xa2/0xb0 mm/madvise.c:1396 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fb1d478c059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb1d30bf168 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007fb1d489f100 RCX: 00007fb1d478c059 RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000000020ffa000 RBP: 00007fb1d47e608d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc2195b4cf R14: 00007fb1d30bf300 R15: 0000000000022000 Allocated by task 29696: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc+0xdc/0x110 mm/kasan/common.c:515 kasan_kmalloc include/linux/kasan.h:270 [inline] __kmalloc+0x253/0x380 mm/slub.c:4424 kmalloc include/linux/slab.h:586 [inline] anon_vma_name_alloc mm/madvise.c:75 [inline] replace_vma_anon_name mm/madvise.c:146 [inline] madvise_update_vma+0x87d/0xa90 mm/madvise.c:212 madvise_vma_anon_name mm/madvise.c:1236 [inline] madvise_walk_vmas mm/madvise.c:1207 [inline] madvise_set_anon_name+0x367/0x520 mm/madvise.c:1269 prctl_set_vma+0x19b/0x220 kernel/sys.c:2305 __do_sys_prctl+0x183/0x1120 kernel/sys.c:2594 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 29697: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x126/0x180 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kfree+0xb8/0x2e0 mm/slub.c:4562 vm_area_free+0x11/0x30 kernel/fork.c:376 __vma_adjust+0x318d/0x3940 mm/mmap.c:962 vma_merge+0xd15/0x1020 madvise_update_vma+0x2b2/0xa90 mm/madvise.c:180 madvise_vma_behavior mm/madvise.c:1043 [inline] madvise_walk_vmas mm/madvise.c:1207 [inline] do_madvise+0xcdf/0x13f0 mm/madvise.c:1385 __do_sys_madvise mm/madvise.c:1398 [inline] __se_sys_madvise mm/madvise.c:1396 [inline] __x64_sys_madvise+0xa2/0xb0 mm/madvise.c:1396 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff8881421af0f0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 4 bytes inside of 8-byte region [ffff8881421af0f0, ffff8881421af0f8) The buggy address belongs to the page: page:ffffea0005086bc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881421afb18 pfn:0x1421af flags: 0x57ff00000000200(slab|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000000200 ffffea00007509c0 dead000000000003 ffff888011441280 raw: ffff8881421afb18 000000008066005f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 2600414944, free_ts 0 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0x729/0x9e0 mm/page_alloc.c:4165 __alloc_pages+0x255/0x580 mm/page_alloc.c:5389 alloc_page_interleave+0x22/0x1c0 mm/mempolicy.c:2116 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0xce/0x3f0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x3fe/0xc30 mm/slub.c:3018 __slab_alloc mm/slub.c:3105 [inline] slab_alloc_node mm/slub.c:3196 [inline] slab_alloc mm/slub.c:3238 [inline] __kmalloc+0x2eb/0x380 mm/slub.c:4420 kmalloc include/linux/slab.h:586 [inline] acpi_os_allocate include/acpi/platform/aclinuxex.h:52 [inline] acpi_ex_allocate_name_string+0xfd/0x330 drivers/acpi/acpica/exnames.c:66 acpi_ex_get_name_string+0x3f6/0x629 drivers/acpi/acpica/exnames.c:367 acpi_ds_create_operand+0x1ad/0xa03 drivers/acpi/acpica/dsutils.c:446 acpi_ds_evaluate_name_path+0x180/0x4ca drivers/acpi/acpica/dsutils.c:771 acpi_ds_exec_end_op+0x245/0x11d2 drivers/acpi/acpica/dswexec.c:374 acpi_ps_parse_loop+0xd9f/0x1cf0 drivers/acpi/acpica/psloop.c:525 acpi_ps_parse_aml+0x1d5/0x955 drivers/acpi/acpica/psparse.c:475 acpi_ps_execute_method+0x5a4/0x6e4 drivers/acpi/acpica/psxface.c:190 acpi_ns_evaluate+0x616/0x9c0 drivers/acpi/acpica/nseval.c:205 acpi_ut_evaluate_object+0x14d/0x491 drivers/acpi/acpica/uteval.c:60 page_owner free stack trace missing Memory state around the buggy address: ffff8881421aef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881421af000: fb fc fc fc fc fb fc fc fc fc fb fc fc fc fc 00 >ffff8881421af080: fc fc fc fc fb fc fc fc fc fb fc fc fc fc fa fc ^ ffff8881421af100: fc fc fc fb fc fc fc fc fb fc fc fc fc fb fc fc ffff8881421af180: fc fc fb fc fc fc fc fb fc fc fc fc fb fc fc fc ==================================================================