[v6.6] KASAN: slab-use-after-free Read in lmLogInit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4a243110dc88 Linux 6.6.114
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=111dcc92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=4132d7149bed686243fd
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1950ac2cd960/disk-4a243110.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d7dccd93693b/vmlinux-4a243110.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6f93496e2b47/bzImage-4a243110.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4132d7...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in lbmLogShutdown fs/jfs/jfs_logmgr.c:1863 [inline]
BUG: KASAN: slab-use-after-free in lmLogInit+0x1165/0x1a30 fs/jfs/jfs_logmgr.c:1416
Read of size 8 at addr ffff88802601e318 by task syz.3.46/6071

CPU: 1 PID: 6071 Comm: syz.3.46 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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
lbmLogShutdown fs/jfs/jfs_logmgr.c:1863 [inline]
lmLogInit+0x1165/0x1a30 fs/jfs/jfs_logmgr.c:1416
open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
lmLogOpen+0x4ef/0xfb0 fs/jfs/jfs_logmgr.c:1069
jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257
jfs_remount+0x396/0x5b0 fs/jfs/super.c:454
reconfigure_super+0x21e/0x880 fs/super.c:1151
do_remount fs/namespace.c:2927 [inline]
path_mount+0xd19/0xfe0 fs/namespace.c:3705
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912
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
RIP: 0033:0x7f9b6958efc9
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:00007f9b677f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9b697e5fa0 RCX: 00007f9b6958efc9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f9b69611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000001c0030 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b697e6038 R14: 00007f9b697e5fa0 R15: 00007ffdcb5851a8
</TASK>

Allocated by task 6071:
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]
lbmLogInit fs/jfs/jfs_logmgr.c:1822 [inline]
lmLogInit+0x355/0x1a30 fs/jfs/jfs_logmgr.c:1270
open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
lmLogOpen+0x4ef/0xfb0 fs/jfs/jfs_logmgr.c:1069
jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257
jfs_remount+0x396/0x5b0 fs/jfs/super.c:454
reconfigure_super+0x21e/0x880 fs/super.c:1151
do_remount fs/namespace.c:2927 [inline]
path_mount+0xd19/0xfe0 fs/namespace.c:3705
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912
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 6071:
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
lbmLogShutdown fs/jfs/jfs_logmgr.c:1865 [inline]
lmLogInit+0x1193/0x1a30 fs/jfs/jfs_logmgr.c:1416
open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
lmLogOpen+0x4ef/0xfb0 fs/jfs/jfs_logmgr.c:1069
jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257
jfs_remount+0x396/0x5b0 fs/jfs/super.c:454
reconfigure_super+0x21e/0x880 fs/super.c:1151
do_remount fs/namespace.c:2927 [inline]
path_mount+0xd19/0xfe0 fs/namespace.c:3705
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912
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

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
insert_work+0x3d/0x310 kernel/workqueue.c:1651
__queue_work+0xd2c/0x1020 kernel/workqueue.c:1804
queue_work_on+0x121/0x1e0 kernel/workqueue.c:1835
inet6addr_event+0xa0/0xd0 drivers/infiniband/core/roce_gid_mgmt.c:882
notifier_call_chain+0x197/0x390 kernel/notifier.c:93
atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:231
ipv6_add_addr+0xdad/0x1090 net/ipv6/addrconf.c:1189
inet6_addr_add+0x57e/0xb60 net/ipv6/addrconf.c:3031
inet6_rtm_newaddr+0x68d/0x940 net/ipv6/addrconf.c:5003
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

The buggy address belongs to the object at ffff88802601e300
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 24 bytes inside of
freed 192-byte region [ffff88802601e300, ffff88802601e3c0)

The buggy address belongs to the physical page:
page:ffffea0000980780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2601e
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888017841a00 ffffea0000ac3a00 dead000000000004
raw: 0000000000000000 0000000000100010 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, tgid 1 (swapper/0), ts 14169495513, 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_page_interleave+0x24/0x1e0 mm/mempolicy.c:2120
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
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0xa4/0x240 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
usb_alloc_urb+0x46/0x140 drivers/usb/core/urb.c:75
hub_configure drivers/usb/core/hub.c:1693 [inline]
hub_probe+0x2354/0x37e0 drivers/usb/core/hub.c:1975
usb_probe_interface+0x5a4/0xb00 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x25b/0xb40 drivers/base/dd.c:658
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:800
driver_probe_device+0x4f/0x420 drivers/base/dd.c:830
__device_attach_driver+0x2ca/0x520 drivers/base/dd.c:958
page_owner free stack trace missing

Memory state around the buggy address:
ffff88802601e200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802601e280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88802601e300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802601e380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff88802601e400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 4a243110dc88 Linux 6.6.114
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=16fc9d42580000

kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=4132d7149bed686243fd
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14907b04580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10b713cd980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1950ac2cd960/disk-4a243110.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d7dccd93693b/vmlinux-4a243110.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6f93496e2b47/bzImage-4a243110.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/bbfb57bc2c85/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=133acbe2580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4132d7...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in lbmLogShutdown fs/jfs/jfs_logmgr.c:1863 [inline]
BUG: KASAN: slab-use-after-free in lmLogInit+0x1165/0x1a30 fs/jfs/jfs_logmgr.c:1416

Read of size 8 at addr ffff888022108518 by task syz.3.868/7764

CPU: 1 PID: 7764 Comm: syz.3.868 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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
lbmLogShutdown fs/jfs/jfs_logmgr.c:1863 [inline]
lmLogInit+0x1165/0x1a30 fs/jfs/jfs_logmgr.c:1416
open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
lmLogOpen+0x4ef/0xfb0 fs/jfs/jfs_logmgr.c:1069
jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257
jfs_remount+0x396/0x5b0 fs/jfs/super.c:454
reconfigure_super+0x21e/0x880 fs/super.c:1151
do_remount fs/namespace.c:2927 [inline]
path_mount+0xd19/0xfe0 fs/namespace.c:3705
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912
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

RIP: 0033:0x7fe6d618efc9

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:00007fe6d7016038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe6d63e5fa0 RCX: 00007fe6d618efc9

RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000

RBP: 00007fe6d6211f91 R08: 0000000000000000 R09: 0000000000000000

R10: 00000000001c0030 R11: 0000000000000246 R12: 0000000000000000

R13: 00007fe6d63e6038 R14: 00007fe6d63e5fa0 R15: 00007ffd0acbbe78
</TASK>

Allocated by task 7764:

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]
lbmLogInit fs/jfs/jfs_logmgr.c:1822 [inline]
lmLogInit+0x355/0x1a30 fs/jfs/jfs_logmgr.c:1270
open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
lmLogOpen+0x4ef/0xfb0 fs/jfs/jfs_logmgr.c:1069
jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257
jfs_remount+0x396/0x5b0 fs/jfs/super.c:454
reconfigure_super+0x21e/0x880 fs/super.c:1151
do_remount fs/namespace.c:2927 [inline]
path_mount+0xd19/0xfe0 fs/namespace.c:3705
do_mount fs/namespace.c:3726 [inline]
__do_sys_mount fs/namespace.c:3935 [inline]
__se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912
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 7764:

__queue_work+0xc39/0x1020 kernel/workqueue.c:1800
queue_work_on+0x121/0x1e0 kernel/workqueue.c:1835
queue_work include/linux/workqueue.h:562 [inline]
call_usermodehelper_exec+0x286/0x490 kernel/umh.c:434
kobject_uevent_env+0x681/0x8c0 lib/kobject_uevent.c:633
device_add+0x5e8/0xc20 drivers/base/core.c:3664
device_create_groups_vargs drivers/base/core.c:4410 [inline]
device_create_with_groups+0x25d/0x2f0 drivers/base/core.c:4490
misc_register+0x40d/0x690 drivers/char/misc.c:264
do_one_initcall+0x1fd/0x750 init/main.c:1250
do_initcall_level+0x137/0x1f0 init/main.c:1312
do_initcalls+0x69/0xd0 init/main.c:1328
kernel_init_freeable+0x3d2/0x570 init/main.c:1565
kernel_init+0x1d/0x1c0 init/main.c:1455
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

The buggy address belongs to the object at ffff888022108500

which belongs to the cache kmalloc-192 of size 192
The buggy address is located 24 bytes inside of

freed 192-byte region [ffff888022108500, ffff8880221085c0)

The buggy address belongs to the physical page:

page:ffffea0000884200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22108

flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()

raw: 00fff00000000800 ffff888017841a00 ffffea000088fdc0 dead000000000002

raw: 0000000000000000 0000000000100010 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 23, tgid 23 (kworker/1:0), ts 6853935075, free_ts 6853270256

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_pages_node include/linux/gfp.h:237 [inline]
alloc_slab_page+0x4f/0x170 mm/slub.c:1883

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_node_trace+0x26/0xe0 mm/slab_common.c:1111
kmalloc_node include/linux/slab.h:616 [inline]
kzalloc_node include/linux/slab.h:732 [inline]
alloc_worker kernel/workqueue.c:2072 [inline]
create_worker+0x119/0x7b0 kernel/workqueue.c:2180
maybe_create_worker kernel/workqueue.c:2463 [inline]
manage_workers kernel/workqueue.c:2515 [inline]
worker_thread+0x4d9/0xfc0 kernel/workqueue.c:2767
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
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
mm_free_pgd kernel/fork.c:809 [inline]
__mmdrop+0xb4/0x3d0 kernel/fork.c:925
free_bprm+0x171/0x3e0 fs/exec.c:1514
kernel_execve+0x3c2/0x9c0 fs/exec.c:2060
call_usermodehelper_exec_async+0x20b/0x350 kernel/umh.c:110
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Memory state around the buggy address:

ffff888022108400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888022108480: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888022108500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888022108580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888022108600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.