syzbot


KASAN: use-after-free Read in lbmIODone (5)

Status: upstream: reported on 2026/04/21 17:46
Reported-by: syzbot+b89d113d29e248f0eb55@syzkaller.appspotmail.com
First crash: 2d11h, last: 2d11h
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 KASAN: use-after-free Read in lbmIODone (4) 19 1 230d 230d 0/3 auto-obsoleted due to no activity on 2025/12/14 20:18
linux-5.15 KASAN: use-after-free Read in lbmIODone (3) 19 1 347d 347d 0/3 auto-obsoleted due to no activity on 2025/08/20 03:33
linux-4.19 KASAN: use-after-free Read in lbmIODone jfs 19 C 150 1165d 2009d 0/1 upstream: reported C repro on 2020/10/22 09:37
upstream KASAN: use-after-free Read in lbmIODone (2) jfs 19 syz 117 672d 1149d 0/29 auto-obsoleted due to no activity on 2024/08/29 23:10
linux-6.1 KASAN: use-after-free Read in lbmIODone 19 1 747d 747d 0/3 auto-obsoleted due to no activity on 2024/07/15 22:58
upstream KASAN: use-after-free Read in lbmIODone jfs 19 syz inconclusive unreliable 20 1501d 2040d 0/29 auto-obsoleted due to no activity on 2023/01/13 19:58
linux-5.15 KASAN: use-after-free Read in lbmIODone (2) 19 1 483d 483d 0/3 auto-obsoleted due to no activity on 2025/04/06 05:07
linux-4.14 KASAN: use-after-free Read in lbmIODone jfs 19 C 68 1166d 2039d 0/1 upstream: reported C repro on 2020/09/23 00:55
linux-5.15 KASAN: use-after-free Read in lbmIODone 19 1 709d 709d 0/3 auto-obsoleted due to no activity on 2024/08/22 10:14
upstream KASAN: slab-use-after-free Read in lbmIODone jfs 19 C error 4407 5m 206d 0/29 upstream: reported C repro on 2025/09/29 13:20

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in lbmIODone+0x12d2/0x1670 fs/jfs/jfs_logmgr.c:2207
Read of size 4 at addr ffff888140748c08 by task ksoftirqd/0/14

CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 lbmIODone+0x12d2/0x1670 fs/jfs/jfs_logmgr.c:2207
 req_bio_endio block/blk-core.c:261 [inline]
 blk_update_request+0x876/0x1200 block/blk-core.c:1441
 blk_mq_end_request+0x3a/0x70 block/blk-mq.c:576
 blk_complete_reqs block/blk-mq.c:588 [inline]
 blk_done_softirq+0xfa/0x140 block/blk-mq.c:593
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:943
 smpboot_thread_fn+0x4f6/0x970 kernel/smpboot.c:164
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 4397:
 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 mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 lbmLogInit fs/jfs/jfs_logmgr.c:1830 [inline]
 lmLogInit+0x353/0x1a60 fs/jfs/jfs_logmgr.c:1278
 open_inline_log fs/jfs/jfs_logmgr.c:1183 [inline]
 lmLogOpen+0x4d0/0xf90 fs/jfs/jfs_logmgr.c:1077
 jfs_mount_rw+0xf8/0x5c0 fs/jfs/jfs_mount.c:253
 jfs_fill_super+0x5c1/0xb00 fs/jfs/super.c:570
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 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 4194:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1873 [inline]
 lmLogShutdown+0x453/0x850 fs/jfs/jfs_logmgr.c:1692
 lmLogClose+0x286/0x520 fs/jfs/jfs_logmgr.c:1468
 jfs_umount+0x28f/0x360 fs/jfs/jfs_umount.c:116
 jfs_put_super+0x88/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x130/0x300 fs/super.c:475
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 insert_work+0x54/0x3d0 kernel/workqueue.c:1366
 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532
 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
 queue_work include/linux/workqueue.h:512 [inline]
 netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:659 [inline]
 netdevice_event+0x803/0x900 drivers/infiniband/core/roce_gid_mgmt.c:802
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline]
 call_netdevice_notifiers net/core/dev.c:2088 [inline]
 dev_set_mac_address+0x2e8/0x400 net/core/dev.c:9140
 dev_set_mac_address_user+0x2d/0x50 net/core/dev.c:9154
 do_setlink+0x8b0/0x3d60 net/core/rtnetlink.c:2739
 __rtnl_newlink net/core/rtnetlink.c:3455 [inline]
 rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3577
 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5687
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2072
 __do_sys_sendto net/socket.c:2084 [inline]
 __se_sys_sendto net/socket.c:2080 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2080
 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

The buggy address belongs to the object at ffff888140748c00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 8 bytes inside of
 192-byte region [ffff888140748c00, ffff888140748cc0)
The buggy address belongs to the page:
page:ffffea000501d200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888140748f00 pfn:0x140748
flags: 0x57ff00000000200(slab|node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000200 ffffea00052ec308 ffff888140000648 ffff888016c41a00
raw: ffff888140748f00 000000000010000f 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 2476207539, free_ts 0
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365
 kobject_uevent_env+0x65e/0x890 lib/kobject_uevent.c:629
 kernel_add_sysfs_param+0xfb/0x120 kernel/params.c:816
 param_sysfs_builtin+0x183/0x200 kernel/params.c:851
 param_sysfs_init+0x66/0x70 kernel/params.c:972
 do_one_initcall+0x272/0x730 init/main.c:1316
 do_initcall_level+0x137/0x1f0 init/main.c:1389
 do_initcalls+0x4b/0x90 init/main.c:1405
 kernel_init_freeable+0x3e9/0x570 init/main.c:1629
 kernel_init+0x19/0x1b0 init/main.c:1520
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888140748b00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888140748b80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888140748c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888140748c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888140748d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/21 17:45 linux-5.15.y b9d57c40a767 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in lbmIODone
* Struck through repros no longer work on HEAD.