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KASAN: slab-use-after-free Read in jfs_lazycommit

Status: upstream: reported C repro on 2025/06/18 00:01
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+abbdf51b9e61595e687d@syzkaller.appspotmail.com
First crash: 123d, last: 1d08h
▶ ▼ Bug presence (1)
Date Name Commit Repro Result
2025/06/22 upstream (ToT) 739a6c93cc75 C [report] KASAN: slab-use-after-free Read in jfs_lazycommit
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in jfs_lazycommit jfs 19 C error 2121 23m 1113d 0/29 upstream: reported C repro on 2022/10/01 13:43
linux-4.19 KASAN: use-after-free Read in jfs_lazycommit jfs 19 C error 5 985d 1102d 0/1 upstream: reported C repro on 2022/10/13 08:33
linux-6.1 KASAN: use-after-free Read in jfs_lazycommit origin:upstream missing-backport 19 C inconclusive 171 6h07m 895d 0/3 upstream: reported C repro on 2023/05/07 23:35
linux-5.15 KASAN: use-after-free Read in jfs_lazycommit origin:upstream 19 C error 227 1d07h 896d 0/3 upstream: reported C repro on 2023/05/06 12:04
linux-4.14 KASAN: use-after-free Read in jfs_lazycommit jfs 19 C 6 961d 1103d 0/1 upstream: reported C repro on 2022/10/11 20:09

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735
Read of size 4 at addr ffff888020f11094 by task jfsCommit/110

CPU: 1 PID: 110 Comm: jfsCommit Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x220 mm/kasan/report.c:468
 kasan_report+0x117/0x150 mm/kasan/report.c:581
 jfs_lazycommit+0x753/0xa60 fs/jfs/jfs_txnmgr.c:2735
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Allocated by task 6207:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 jfs_fill_super+0xd6/0xac0 fs/jfs/super.c:495
 mount_bdev+0x22b/0x2d0 fs/super.c:1643
 legacy_get_tree+0xea/0x180 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3377
 do_mount fs/namespace.c:3717 [inline]
 __do_sys_mount fs/namespace.c:3926 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3903
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 5914:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 generic_shutdown_super+0x134/0x2b0 fs/super.c:693
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2721 [inline]
 call_rcu+0x158/0x930 kernel/rcu/tree.c:2837
 fib_create_info+0x1845/0x2460 net/ipv4/fib_semantics.c:1590
 fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217
 fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x38d/0x5e0 net/ipv4/fib_frontend.c:1155
 fib_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 __dev_notify_flags+0x18e/0x2e0 net/core/dev.c:-1
 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8762
 do_setlink+0xc74/0x3fb0 net/core/rtnetlink.c:2905
 __rtnl_newlink net/core/rtnetlink.c:3703 [inline]
 rtnl_newlink+0x175b/0x2020 net/core/rtnetlink.c:3750
 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x46a/0x620 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Second to last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
 __call_rcu_common kernel/rcu/tree.c:2721 [inline]
 call_rcu+0x158/0x930 kernel/rcu/tree.c:2837
 fib_create_info+0x1845/0x2460 net/ipv4/fib_semantics.c:1590
 fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217
 fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x3fb/0x5e0 net/ipv4/fib_frontend.c:1162
 fib_inetaddr_event+0x140/0x1d0 net/ipv4/fib_frontend.c:1454
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:388
 __inet_insert_ifa+0x9ae/0xbb0 net/ipv4/devinet.c:570
 inet_rtm_newaddr+0x1014/0x1a00 net/ipv4/devinet.c:986
 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6475
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595
 ___sys_sendmsg+0x220/0x290 net/socket.c:2649
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2687 [inline]
 __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888020f11000
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 148 bytes inside of
 freed 256-byte region [ffff888020f11000, ffff888020f11100)

The buggy address belongs to the physical page:
page:ffffea000083c400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20f10
head:ffffea000083c400 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841b40 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 8982039251, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2081
 ___slab_alloc+0xc6d/0x1300 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3534
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 set_kthread_struct+0xb7/0x1f0 kernel/kthread.c:118
 copy_process+0x107a/0x3d70 kernel/fork.c:2433
 kernel_clone+0x21b/0x840 kernel/fork.c:2914
 kernel_thread+0x10d/0x160 kernel/fork.c:2976
 create_kthread kernel/kthread.c:411 [inline]
 kthreadd+0x560/0x730 kernel/kthread.c:766
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888020f10f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888020f11000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888020f11080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888020f11100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888020f11180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (38):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/28 19:29 linux-6.6.y 147338df3487 001c9061 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/20 07:33 linux-6.6.y 6282921b6825 ed3e87f7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/10/18 01:28 linux-6.6.y 0bbbd97a442d 1c8c8cd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/10/17 14:11 linux-6.6.y 0bbbd97a442d 7adf5298 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/10/12 15:43 linux-6.6.y 655054d2c3c1 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/10/12 06:54 linux-6.6.y e617101e5626 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/10/06 15:41 linux-6.6.y e617101e5626 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/10/04 09:48 linux-6.6.y f34f16e5c632 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/29 13:44 linux-6.6.y 147338df3487 86341da6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/29 01:11 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/28 16:55 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/28 16:54 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/28 16:52 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/28 16:49 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/28 16:48 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/26 22:57 linux-6.6.y 147338df3487 001c9061 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/25 20:19 linux-6.6.y 147338df3487 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/25 13:30 linux-6.6.y 147338df3487 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/23 21:05 linux-6.6.y af1544b5d072 e667a34f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/09/02 01:24 linux-6.6.y cc1a1c5b404a 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/20 04:50 linux-6.6.y bb9c90ab9c5a 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/19 23:44 linux-6.6.y bb9c90ab9c5a 254a27c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/19 08:07 linux-6.6.y bb9c90ab9c5a 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/19 04:21 linux-6.6.y bb9c90ab9c5a 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/17 07:14 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/15 05:40 linux-6.6.y 3a8ababb8b6a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/09 20:57 linux-6.6.y 3a8ababb8b6a 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/03 18:19 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/08/03 06:56 linux-6.6.y 3a8ababb8b6a 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/07/08 12:10 linux-6.6.y a5df3a702b2c 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/07/06 13:49 linux-6.6.y a5df3a702b2c 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/07/01 16:09 linux-6.6.y 3f5b4c104b7d 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/30 07:48 linux-6.6.y 3f5b4c104b7d fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/28 00:38 linux-6.6.y 3f5b4c104b7d fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/27 14:43 linux-6.6.y 3f5b4c104b7d 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/21 03:34 linux-6.6.y 6282921b6825 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/19 16:24 linux-6.6.y 6282921b6825 ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
2025/06/17 23:15 linux-6.6.y c2603c511feb e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_lazycommit
* Struck through repros no longer work on HEAD.