KASAN: use-after-free Write in detach_if_pending

Status: auto-obsoleted due to no activity on 2025/05/18 23:57
Reported-by: syzbot+5f9c6c4ed9d81b487949@syzkaller.appspotmail.com
First crash: 657d, last: 534d
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 KASAN: use-after-free Write in detach_if_pending 22 syz, C 1618 437d 1273d 0/2 upstream: reported C repro on 2023/02/10 18:19
upstream KASAN: use-after-free Write in detach_if_pending net 22 syz, C 4169 3210d 3205d 3/29 fixed on 2017/11/28 03:36
android-6-1 KASAN: use-after-free Write in detach_if_pending (2) 22 22 47d 425d 0/2 premoderation: reported on 2025/06/06 23:25
upstream general protection fault in detach_if_pending (2) net 2 1 1607d 1607d 0/29 auto-closed as invalid on 2022/06/11 02:46
linux-4.14 general protection fault in detach_if_pending (2) 2 1 1917d 1917d 0/1 auto-closed as invalid on 2021/09/04 11:36
upstream general protection fault in detach_if_pending (3) fs kvm 2 5 772d 772d 0/29 closed as invalid on 2024/08/16 18:25
upstream KASAN: invalid-access Write in detach_if_pending wireguard -1 2 1997d 1999d 0/29 auto-closed as invalid on 2021/05/17 08:51
upstream KASAN: slab-use-after-free Write in detach_if_pending batman wireguard 22 2 1189d 1198d 0/29 auto-obsoleted due to no activity on 2023/11/08 05:10
android-54 BUG: Bad page map (4) -1 18 448d 548d 0/2 auto-obsoleted due to no activity on 2025/08/04 13:44

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:884 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:886 [inline]
BUG: KASAN: use-after-free in detach_if_pending+0x1ab/0x390 kernel/time/timer.c:905
Write of size 8 at addr ffff8881130489f8 by task syz.2.352/1582

CPU: 1 PID: 1582 Comm: syz.2.352 Not tainted 6.1.124-syzkaller-00008-gccc915784332 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356
 __hlist_del include/linux/list.h:884 [inline]
 detach_timer kernel/time/timer.c:886 [inline]
 detach_if_pending+0x1ab/0x390 kernel/time/timer.c:905
 del_timer+0xcf/0x140 kernel/time/timer.c:1287
 try_to_grab_pending+0xeb/0x5d0 kernel/workqueue.c:1285
 mod_delayed_work_on+0xb3/0x190 kernel/workqueue.c:1745
 mod_delayed_work include/linux/workqueue.h:540 [inline]
 wb_wakeup fs/fs-writeback.c:139 [inline]
 wb_start_writeback fs/fs-writeback.c:1226 [inline]
 __wakeup_flusher_threads_bdi+0x261/0x2e0 fs/fs-writeback.c:2299
 wakeup_flusher_threads+0xac/0xf0 fs/fs-writeback.c:2324
 ksys_sync+0xab/0x1c0 fs/sync.c:101
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 x64_sys_call+0x488/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:163
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fac2198cde9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fac22872038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fac21ba5fa0 RCX: 00007fac2198cde9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fac21ba5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fac21ba5fa0 R15: 00007ffe96a996b8
 </TASK>

Allocated by task 1530:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 __do_kmalloc_node mm/slab_common.c:938 [inline]
 __kmalloc+0xb4/0x1e0 mm/slab_common.c:951
 kmalloc include/linux/slab.h:568 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 hci_alloc_dev_priv+0x27/0x1c00 net/bluetooth/hci_core.c:2435
 hci_alloc_dev include/net/bluetooth/hci_core.h:1484 [inline]
 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:636 [inline]
 hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:712 [inline]
 hci_uart_tty_ioctl+0x401/0xa70 drivers/bluetooth/hci_ldisc.c:765
 tty_ioctl+0x903/0xc50 drivers/tty/tty_io.c:2785
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0x114/0x190 fs/ioctl.c:856
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
 x64_sys_call+0x98/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 1530:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1745 [inline]
 slab_free_freelist_hook mm/slub.c:1771 [inline]
 slab_free mm/slub.c:3686 [inline]
 __kmem_cache_free+0x21d/0x410 mm/slub.c:3702
 kfree+0x7a/0xf0 mm/slab_common.c:990
 hci_release_dev+0x14d3/0x1640 net/bluetooth/hci_core.c:2763
 bt_host_release+0x83/0xa0 net/bluetooth/hci_sysfs.c:85
 device_release+0x95/0x1c0
 kobject_cleanup lib/kobject.c:681 [inline]
 kobject_release lib/kobject.c:712 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x178/0x260 lib/kobject.c:729
 put_device+0x1f/0x30 drivers/base/core.c:3805
 hci_dev_put include/net/bluetooth/hci_core.h:1444 [inline]
 hci_dev_cmd+0x2be/0x9b0 net/bluetooth/hci_core.c:795
 hci_sock_ioctl+0x415/0x7f0 net/bluetooth/hci_sock.c:1096
 sock_do_ioctl+0x152/0x450 net/socket.c:1194
 sock_ioctl+0x455/0x740 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0x114/0x190 fs/ioctl.c:856
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
 x64_sys_call+0x98/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 insert_work+0x56/0x310 kernel/workqueue.c:1368
 __queue_work+0x9b6/0xd70 kernel/workqueue.c:1527
 queue_work_on+0x105/0x170 kernel/workqueue.c:1555
 queue_work include/linux/workqueue.h:510 [inline]
 hci_cmd_sync_run net/bluetooth/hci_sync.c:140 [inline]
 __hci_cmd_sync_sk+0xc2a/0xf70 net/bluetooth/hci_sync.c:162
 __hci_cmd_sync_status_sk net/bluetooth/hci_sync.c:253 [inline]
 __hci_cmd_sync_status net/bluetooth/hci_sync.c:277 [inline]
 hci_cmd_sync_status+0x52/0x130 net/bluetooth/hci_sync.c:288
 hci_dev_cmd+0x771/0x9b0
 hci_sock_ioctl+0x415/0x7f0 net/bluetooth/hci_sock.c:1096
 sock_do_ioctl+0x152/0x450 net/socket.c:1194
 sock_ioctl+0x455/0x740 net/socket.c:1311
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0x114/0x190 fs/ioctl.c:856
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
 x64_sys_call+0x98/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Second to last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 insert_work+0x56/0x310 kernel/workqueue.c:1368
 __queue_work+0x9b6/0xd70 kernel/workqueue.c:1527
 queue_work_on+0x105/0x170 kernel/workqueue.c:1555
 queue_work include/linux/workqueue.h:510 [inline]
 hci_cmd_timeout+0x199/0x200 net/bluetooth/hci_core.c:1468
 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
 kthread+0x26d/0x300 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888113048000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2552 bytes inside of
 8192-byte region [ffff888113048000, ffff88811304a000)

The buggy address belongs to the physical page:
page:ffffea00044c1200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113048
head:ffffea00044c1200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043500
raw: 0000000000000000 0000000000020002 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 1530, tgid 1529 (syz.1.338), ts 93100923295, free_ts 93090147126
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x213/0x220 mm/page_alloc.c:2637
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2644
 get_page_from_freelist+0x3a98/0x3b10 mm/page_alloc.c:4539
 __alloc_pages+0x234/0x610 mm/page_alloc.c:5837
 alloc_slab_page+0x6c/0xf0
 allocate_slab mm/slub.c:1962 [inline]
 new_slab+0x90/0x3e0 mm/slub.c:2015
 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203
 __slab_alloc+0x5d/0xa0 mm/slub.c:3302
 slab_alloc_node mm/slub.c:3387 [inline]
 __kmem_cache_alloc_node+0x207/0x2a0 mm/slub.c:3462
 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1028
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 fat_fill_super+0x112/0x4d70 fs/fat/inode.c:1625
 vfat_fill_super+0x31/0x40 fs/fat/namei_vfat.c:1200
 mount_bdev+0x282/0x3b0 fs/super.c:1445
 vfat_mount+0x34/0x40 fs/fat/namei_vfat.c:1207
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:632
 vfs_get_tree+0x88/0x290 fs/super.c:1575
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1545 [inline]
 free_pcp_prepare mm/page_alloc.c:1619 [inline]
 free_unref_page_prepare+0x9f1/0xa00 mm/page_alloc.c:3581
 free_unref_page+0xb2/0x5c0 mm/page_alloc.c:3677
 free_the_page mm/page_alloc.c:830 [inline]
 __free_pages+0x61/0xf0 mm/page_alloc.c:5926
 __free_slab+0xce/0x1a0 mm/slub.c:2039
 free_slab mm/slub.c:2054 [inline]
 discard_slab mm/slub.c:2060 [inline]
 __unfreeze_partials+0x165/0x1a0 mm/slub.c:2609
 put_cpu_partial+0xa9/0x100 mm/slub.c:2685
 __slab_free+0x1c8/0x280 mm/slub.c:3563
 do_slab_free mm/slub.c:3640 [inline]
 ___cache_free+0xc6/0xd0 mm/slub.c:3696
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0xc5/0x140 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x15a/0x180 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3421 [inline]
 __kmem_cache_alloc_node+0x193/0x2a0 mm/slub.c:3462
 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1028
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 kernfs_iop_get_link+0x65/0x610 fs/kernfs/symlink.c:135
 vfs_readlink+0x166/0x390 fs/namei.c:5122

Memory state around the buggy address:
 ffff888113048880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888113048900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888113048980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff888113048a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888113048a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/17 23:57 android14-6.1 ccc915784332 429ea007 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Write in detach_if_pending
2025/02/08 15:12 android14-6.1 1ac09f5c0571 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Write in detach_if_pending
2025/01/07 02:44 android14-6.1 eeccb2921815 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Write in detach_if_pending
2024/12/19 06:51 android14-6.1 e50cf165f4e7 1432fc84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Write in detach_if_pending
2024/10/18 20:01 android14-6.1 299cc91948f1 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Write in detach_if_pending
* Struck through repros no longer work on HEAD.