syzbot

 sign-in | mailing list | source | docs
🐞 Open [117]
🐞 Fixed [23]
🐞 Invalid [357]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

KASAN: use-after-free Read in unaccount_page_cache_page (2)

Status: premoderation: reported on 2024/08/23 02:36
Reported-by: syzbot+2660878ed6b4da17c8aa@syzkaller.appspotmail.com
First crash: 542d, last: 17h32m
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page 19 118 712d 1187d 0/2 auto-obsoleted due to no activity on 2024/05/01 01:14
android-5-10 KASAN: use-after-free Read in unaccount_page_cache_page (3) 19 97 8h16m 412d 0/2 premoderation: reported on 2024/12/31 14:15
android-5-10 KASAN: use-after-free Read in unaccount_page_cache_page 19 150 666d 1194d 0/2 auto-obsoleted due to no activity on 2024/06/10 16:28
android-54 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page 19 2 747d 828d 0/2 auto-obsoleted due to no activity on 2024/04/30 10:15
android-5-10 KASAN: use-after-free Read in unaccount_page_cache_page (2) 19 1 551d 551d 0/2 auto-obsoleted due to no activity on 2024/11/11 21:33
android-54 KASAN: use-after-free Read in unaccount_page_cache_page 19 143 978d 1192d 0/2 auto-obsoleted due to no activity on 2023/08/23 09:09
android-54 KASAN: use-after-free Read in unaccount_page_cache_page (2) 19 5 270d 295d 0/2 auto-obsoleted due to no activity on 2025/08/20 03:09

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in cleancache_fs_enabled_mapping include/linux/cleancache.h:56 [inline]
BUG: KASAN: use-after-free in cleancache_invalidate_page include/linux/cleancache.h:110 [inline]
BUG: KASAN: use-after-free in unaccount_page_cache_page+0x6f2/0x760 mm/filemap.c:172
Read of size 4 at addr ffff88811ab54470 by task kswapd0/46

CPU: 0 PID: 46 Comm: kswapd0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0xf1/0x140 mm/kasan/report.c:444
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 cleancache_fs_enabled_mapping include/linux/cleancache.h:56 [inline]
 cleancache_invalidate_page include/linux/cleancache.h:110 [inline]
 unaccount_page_cache_page+0x6f2/0x760 mm/filemap.c:172
 __delete_from_page_cache+0xbe/0x470 mm/filemap.c:240
 __remove_mapping+0x80a/0x980 mm/vmscan.c:1216
 shrink_page_list+0x24fc/0x5540 mm/vmscan.c:1824
 shrink_inactive_list mm/vmscan.c:2331 [inline]
 shrink_list mm/vmscan.c:2576 [inline]
 shrink_lruvec+0x1209/0x39a0 mm/vmscan.c:5793
 shrink_node_memcgs mm/vmscan.c:5985 [inline]
 shrink_node+0x1205/0x2aa0 mm/vmscan.c:6015
 kswapd_shrink_node mm/vmscan.c:6766 [inline]
 balance_pgdat+0x1000/0x21f0 mm/vmscan.c:6956
 kswapd+0x65b/0xcd0 mm/vmscan.c:7215
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 1343:
 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:433 [inline]
 ____kasan_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:521
 kasan_kmalloc include/linux/kasan.h:227 [inline]
 __kmalloc+0x13d/0x2c0 mm/slub.c:4436
 kmalloc include/linux/slab.h:624 [inline]
 sk_prot_alloc+0xed/0x320 net/core/sock.c:1868
 sk_alloc+0x38/0x430 net/core/sock.c:1928
 __netlink_create net/netlink/af_netlink.c:629 [inline]
 netlink_create+0x3c2/0x630 net/netlink/af_netlink.c:692
 __sock_create+0x38d/0x7a0 net/socket.c:1485
 sock_create net/socket.c:1541 [inline]
 __sys_socket+0xec/0x190 net/socket.c:1583
 __do_sys_socket net/socket.c:1592 [inline]
 __se_sys_socket net/socket.c:1590 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1590
 x64_sys_call+0x8c5/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:42
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Freed by task 360:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:365
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373
 kasan_slab_free include/linux/kasan.h:193 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754
 slab_free mm/slub.c:3526 [inline]
 kfree+0xc4/0x270 mm/slub.c:4588
 sk_prot_free net/core/sock.c:1911 [inline]
 __sk_destruct+0x4c0/0x5e0 net/core/sock.c:1997
 sk_destruct net/core/sock.c:2012 [inline]
 __sk_free+0x313/0x410 net/core/sock.c:2023
 sk_free+0x54/0x90 net/core/sock.c:2034
 deferred_put_nlk_sk+0xa6/0xe0 net/netlink/af_netlink.c:723
 rcu_do_batch+0x532/0xbe0 kernel/rcu/tree.c:2523
 rcu_core+0x5ee/0xf80 kernel/rcu/tree.c:2763
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 __do_softirq kernel/softirq.c:621 [inline]
 invoke_softirq kernel/softirq.c:443 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:670
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:682
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:676

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu_common kernel/rcu/tree.c:3011 [inline]
 call_rcu+0x10b/0xf80 kernel/rcu/tree.c:3129
 netlink_release+0x12ea/0x1710 net/netlink/af_netlink.c:803
 __sock_release net/socket.c:649 [inline]
 sock_close+0xe0/0x270 net/socket.c:1335
 __fput+0x20b/0x8b0 fs/file_table.c:311
 ____fput+0x15/0x20 fs/file_table.c:339
 task_work_run+0x127/0x190 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xa9e/0x27e0 kernel/exit.c:889
 do_group_exit+0x141/0x310 kernel/exit.c:1003
 get_signal+0x66a/0x1480 kernel/signal.c:2907
 arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:280

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 insert_work+0x51/0x310 kernel/workqueue.c:1373
 __queue_work+0x8e5/0xc60 kernel/workqueue.c:1539
 queue_work_on+0xde/0x150 kernel/workqueue.c:1566
 queue_work include/linux/workqueue.h:510 [inline]
 schedule_work include/linux/workqueue.h:571 [inline]
 destroy_super_rcu+0xd1/0xe0 fs/super.c:172
 rcu_do_batch+0x532/0xbe0 kernel/rcu/tree.c:2523
 rcu_core+0x5ee/0xf80 kernel/rcu/tree.c:2763
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2776
 handle_softirqs+0x250/0x560 kernel/softirq.c:583
 run_ksoftirqd+0x28/0x40 kernel/softirq.c:959
 smpboot_thread_fn+0x45a/0x8c0 kernel/smpboot.c:164
 kthread+0x411/0x500 kernel/kthread.c:337
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff88811ab54000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1136 bytes inside of
 2048-byte region [ffff88811ab54000, ffff88811ab54800)
The buggy address belongs to the page:
page:ffffea00046ad400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ab50
head:ffffea00046ad400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 0000000200000001 ffff888100043200
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 139, ts 6655552901, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611
 get_page_from_freelist+0x2d3a/0x2dc0 mm/page_alloc.c:4485
 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5808
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa1/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x381/0x810 mm/slub.c:3033
 __slab_alloc+0x49/0x90 mm/slub.c:3120
 slab_alloc_node mm/slub.c:3211 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 __kmalloc+0x16a/0x2c0 mm/slub.c:4432
 kmalloc include/linux/slab.h:624 [inline]
 sk_prot_alloc+0xed/0x320 net/core/sock.c:1868
 sk_alloc+0x38/0x430 net/core/sock.c:1928
 __netlink_create net/netlink/af_netlink.c:629 [inline]
 netlink_create+0x3c2/0x630 net/netlink/af_netlink.c:692
 __sock_create+0x38d/0x7a0 net/socket.c:1485
 sock_create net/socket.c:1541 [inline]
 __sys_socket+0xec/0x190 net/socket.c:1583
 __do_sys_socket net/socket.c:1592 [inline]
 __se_sys_socket net/socket.c:1590 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1590
 x64_sys_call+0x8c5/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:42
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88811ab54300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811ab54380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811ab54400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff88811ab54480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811ab54500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (161):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/15 23:12 android13-5.15-lts 13d6d33696ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/14 17:19 android13-5.15-lts 13d6d33696ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/12 12:41 android13-5.15-lts c3393955a6be 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/11 10:07 android13-5.15-lts c3393955a6be 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/04 12:39 android13-5.15-lts 7e1070528954 42b01fab .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/02 02:56 android13-5.15-lts 7e1070528954 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/01 20:04 android13-5.15-lts 7e1070528954 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/01 06:23 android13-5.15-lts 7e1070528954 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/30 06:35 android13-5.15-lts 7e1070528954 bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/27 20:24 android13-5.15-lts 7e1070528954 9a514c2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/26 07:21 android13-5.15-lts 00b50d06692d 55756628 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/25 17:02 android13-5.15-lts 00b50d06692d 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/25 15:51 android13-5.15-lts 00b50d06692d 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/18 22:49 android13-5.15-lts 050dc55b0457 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/18 01:22 android13-5.15-lts 050dc55b0457 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/16 16:19 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/15 14:12 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/14 23:07 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/14 00:48 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/13 14:16 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/12 18:52 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/12 17:28 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/12 16:11 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/12 06:49 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/11 19:51 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/11 10:31 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/10 02:42 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/09 17:37 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/09 06:15 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/08 22:40 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/07 23:45 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/07 16:11 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/07 03:01 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/05 18:56 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/03 22:37 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/03 00:03 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/02 19:47 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/01/02 08:43 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: use-after-free Read in unaccount_page_cache_page
2026/02/15 01:58 android13-5.15-lts 13d6d33696ef 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page
2026/02/03 06:38 android13-5.15-lts 7e1070528954 d78927dd .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page
2026/01/30 07:41 android13-5.15-lts 7e1070528954 bfa73b7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page
2026/01/10 12:00 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page
2026/01/10 08:47 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page
2026/01/03 03:52 android13-5.15-lts 050dc55b0457 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 KASAN: slab-out-of-bounds Read in unaccount_page_cache_page
* Struck through repros no longer work on HEAD.