syzbot

==================================================================
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 ]---