================================================================== BUG: KASAN: use-after-free in __efivar_entry_iter+0x10c/0x19c Read of size 8 at addr ffff00012c838828 by task syz-executor.0/8402 CPU: 0 PID: 8402 Comm: syz-executor.0 Not tainted 5.15.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x174/0x1e4 mm/kasan/report.c:451 __asan_report_load8_noabort+0x44/0x50 mm/kasan/report_generic.c:309 __efivar_entry_iter+0x10c/0x19c efivarfs_kill_sb+0x3c/0x4c fs/efivarfs/super.c:249 deactivate_locked_super+0xb8/0x13c fs/super.c:335 deactivate_super+0x108/0x128 fs/super.c:366 cleanup_mnt+0x3c0/0x474 fs/namespace.c:1143 __cleanup_mnt+0x20/0x30 fs/namespace.c:1150 task_work_run+0x130/0x1e4 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:597 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Allocated by task 8402: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc+0xbc/0xfc mm/kasan/common.c:513 __kasan_kmalloc+0x10/0x1c mm/kasan/common.c:522 kasan_kmalloc include/linux/kasan.h:264 [inline] kmem_cache_alloc_trace+0x27c/0x47c mm/slub.c:3247 kmalloc include/linux/slab.h:591 [inline] kzalloc include/linux/slab.h:721 [inline] efivarfs_callback+0x118/0x674 fs/efivarfs/super.c:119 efivar_init+0x614/0x9f4 drivers/firmware/efi/vars.c:474 efivarfs_fill_super+0x1c4/0x260 fs/efivarfs/super.c:222 vfs_get_super fs/super.c:1150 [inline] get_tree_single+0xb8/0x170 fs/super.c:1188 efivarfs_get_tree+0x28/0x38 fs/efivarfs/super.c:231 vfs_get_tree+0x90/0x274 fs/super.c:1508 do_new_mount+0x25c/0x8c4 fs/namespace.c:2994 path_mount+0x590/0x104c fs/namespace.c:3324 do_mount fs/namespace.c:3337 [inline] __do_sys_mount fs/namespace.c:3545 [inline] __se_sys_mount fs/namespace.c:3522 [inline] __arm64_sys_mount+0x510/0x5e0 fs/namespace.c:3522 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:596 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Freed by task 8401: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x84 mm/kasan/common.c:46 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0x128/0x1ec mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0x178/0x410 mm/slub.c:4559 efivarfs_destroy+0x48/0x5c fs/efivarfs/super.c:189 __efivar_entry_iter+0x11c/0x19c drivers/firmware/efi/vars.c:1089 efivarfs_kill_sb+0x3c/0x4c fs/efivarfs/super.c:249 deactivate_locked_super+0xb8/0x13c fs/super.c:335 deactivate_super+0x108/0x128 fs/super.c:366 cleanup_mnt+0x3c0/0x474 fs/namespace.c:1143 __cleanup_mnt+0x20/0x30 fs/namespace.c:1150 task_work_run+0x130/0x1e4 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:597 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 The buggy address belongs to the object at ffff00012c838000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2088 bytes inside of 4096-byte region [ffff00012c838000, ffff00012c839000) The buggy address belongs to the page: page:00000000b86182b2 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16c838 head:00000000b86182b2 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 dead000000000100 dead000000000122 ffff0000c0002a80 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff00012c838700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff00012c838780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff00012c838800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff00012c838880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff00012c838900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== list_del corruption, ffff00012c838828->next is LIST_POISON1 (dead000000000100) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:55! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 8402 Comm: syz-executor.0 Tainted: G B 5.15.122-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __list_del_entry_valid+0x110/0x150 lib/list_debug.c:53 lr : __list_del_entry_valid+0x110/0x150 lib/list_debug.c:53 sp : ffff8000279778b0 x29: ffff8000279778b0 x28: 1ffff00002921a9d x27: 0000000000000000 x26: dfff800000000000 x25: dead000000000100 x24: ffff80001490d320 x23: dfff800000000000 x22: dead000000000100 x21: dfff800000000000 x20: dead000000000122 x19: ffff00012c838828 x18: 1fffe000368feb8e x17: 1fffe000368feb8e x16: ffff800011967f54 x15: ffff8000149af100 x14: ffff0001b47f5c80 x13: ffffffffffffffff x12: 0000000000000000 x11: ff8080000832d958 x10: 0000000000000000 x9 : 41a46bcf0f0ee600 x8 : 41a46bcf0f0ee600 x7 : 0000000000000000 x6 : ffff800008268c70 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff80000a958860 x2 : ffff0001b47f5d10 x1 : 0000000100000000 x0 : 000000000000004e Call trace: __list_del_entry_valid+0x110/0x150 lib/list_debug.c:53 __list_del_entry include/linux/list.h:132 [inline] list_del include/linux/list.h:146 [inline] efivar_entry_remove+0x64/0x14c drivers/firmware/efi/vars.c:539 efivarfs_destroy+0x20/0x5c fs/efivarfs/super.c:185 __efivar_entry_iter+0x11c/0x19c drivers/firmware/efi/vars.c:1089 efivarfs_kill_sb+0x3c/0x4c fs/efivarfs/super.c:249 deactivate_locked_super+0xb8/0x13c fs/super.c:335 deactivate_super+0x108/0x128 fs/super.c:366 cleanup_mnt+0x3c0/0x474 fs/namespace.c:1143 __cleanup_mnt+0x20/0x30 fs/namespace.c:1150 task_work_run+0x130/0x1e4 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] do_notify_resume+0x262c/0x32b8 arch/arm64/kernel/signal.c:946 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline] el0_svc+0xfc/0x1f0 arch/arm64/kernel/entry-common.c:597 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:614 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Code: 91088000 aa1303e1 f2fbd5a2 95beabf8 (d4210000) ---[ end trace df912851df6064ca ]---