syzbot


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

Status: upstream: reported C repro on 2025/06/21 09:40
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+1473770ca06b052afcaa@syzkaller.appspotmail.com
First crash: 69d, last: 1d04h
Bug presence (1)
Date Name Commit Repro Result
2025/06/29 upstream (ToT) dfba48a70cb6 C [report] general protection fault in lmLogSync
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in jfs_syncpt jfs 19 C inconclusive 1028 11h14m 569d 0/29 upstream: reported C repro on 2024/02/07 09:29
linux-5.15 KASAN: use-after-free Read in jfs_syncpt origin:upstream 19 C 122 1d08h 563d 0/3 upstream: reported C repro on 2024/02/13 19:07
linux-6.1 KASAN: use-after-free Read in jfs_syncpt origin:upstream 19 C 147 1d05h 504d 0/3 upstream: reported C repro on 2024/04/12 18:15

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:197 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:681 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0x6cb/0xcc0 kernel/locking/mutex.c:747
Read of size 8 at addr ffff888079684908 by task jfsCommit/111

CPU: 0 PID: 111 Comm: jfsCommit Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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
 __mutex_waiter_is_first kernel/locking/mutex.c:197 [inline]
 __mutex_lock_common kernel/locking/mutex.c:681 [inline]
 __mutex_lock+0x6cb/0xcc0 kernel/locking/mutex.c:747
 jfs_syncpt+0x25/0x90 fs/jfs/jfs_logmgr.c:1039
 txEnd+0x2e5/0x520 fs/jfs/jfs_txnmgr.c:549
 txLazyCommit fs/jfs/jfs_txnmgr.c:2684 [inline]
 jfs_lazycommit+0x5a6/0xa60 fs/jfs/jfs_txnmgr.c:2732
 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 5993:
 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]
 open_inline_log fs/jfs/jfs_logmgr.c:1159 [inline]
 lmLogOpen+0x2df/0xfb0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xea/0x670 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x592/0xac0 fs/jfs/super.c:565
 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:3371
 do_mount fs/namespace.c:3711 [inline]
 __do_sys_mount fs/namespace.c:3920 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897
 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 5922:
 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:1806 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832
 slab_free mm/slub.c:3816 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829
 lmLogClose+0x297/0x520 fs/jfs/jfs_logmgr.c:-1
 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 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+0xb1/0x140 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

The buggy address belongs to the object at ffff888079684800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 264 bytes inside of
 freed 1024-byte region [ffff888079684800, ffff888079684c00)

The buggy address belongs to the physical page:
page:ffffea0001e5a000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79680
head:ffffea0001e5a000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841dc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 3002, tgid 3002 (kworker/u4:11), ts 120450881431, free_ts 120355436329
 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:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc+0xa4/0x240 mm/slab_common.c:1020
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 ieee802_11_parse_elems_full+0xb9/0x2080 net/mac80211/util.c:1616
 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2337 [inline]
 ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2344 [inline]
 ieee80211_inform_bss+0x107/0x1060 net/mac80211/scan.c:79
 rdev_inform_bss+0x106/0x410 net/wireless/rdev-ops.h:418
 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2985 [inline]
 cfg80211_inform_bss_frame_data+0xb33/0x12b0 net/wireless/scan.c:3012
 ieee80211_bss_info_update+0x70b/0x930 net/mac80211/scan.c:211
 ieee80211_rx_bss_info net/mac80211/ibss.c:1124 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1613 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x17c9/0x2ac0 net/mac80211/ibss.c:1642
 ieee80211_iface_process_skb net/mac80211/iface.c:1643 [inline]
 ieee80211_iface_work+0x717/0xc70 net/mac80211/iface.c:1697
 cfg80211_wiphy_work+0x225/0x260 net/wireless/core.c:437
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
 discard_slab mm/slub.c:2122 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
 put_cpu_partial+0x17c/0x250 mm/slub.c:2738
 __slab_free+0x31d/0x410 mm/slub.c:3686
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530
 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
 alloc_skb include/linux/skbuff.h:1284 [inline]
 nlmsg_new include/net/netlink.h:999 [inline]
 devlink_port_notify+0x7e/0x230 net/devlink/port.c:511
 __devlink_port_type_set+0x525/0x6b0 net/devlink/port.c:1171
 devlink_port_netdevice_event+0x2a9/0x4f0 net/devlink/port.c:1250
 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_change_name+0x5d4/0x8a0 net/core/dev.c:1300

Memory state around the buggy address:
 ffff888079684800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888079684880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888079684900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888079684980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888079684a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/18 03:52 linux-6.6.y bb9c90ab9c5a 1804e95e .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_syncpt
2025/06/22 06:37 linux-6.6.y 6282921b6825 d6cdfb8a .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_syncpt
2025/08/23 01:11 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/08/28 20:09 linux-6.6.y cc1a1c5b404a d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/08/24 22:13 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/08/09 22:31 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_syncpt
2025/07/18 22:19 linux-6.6.y d96eb99e2f0e 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/07/14 06:07 linux-6.6.y 59a2de10b81a 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/07/05 09:31 linux-6.6.y 3f5b4c104b7d 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/07/03 19:02 linux-6.6.y 3f5b4c104b7d 115ceea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan KASAN: slab-use-after-free Read in jfs_syncpt
2025/06/27 12:50 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_syncpt
2025/06/21 09:39 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_syncpt
* Struck through repros no longer work on HEAD.