syzbot


KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass

Status: upstream: reported C repro on 2024/04/05 10:01
Subsystems: jffs2
[Documentation on labels]
Reported-by: syzbot+e84662c5f30b8c401437@syzkaller.appspotmail.com
First crash: 53d, last: 21d
Cause bisection: introduced by (bisect log) :
commit 9c8ad7a2ff0bfe58f019ec0abc1fb965114dde7d
Author: David Howells <dhowells@redhat.com>
Date: Thu May 16 11:52:27 2019 +0000

  uapi, x86: Fix the syscall numbering of the mount API syscalls [ver #2]

Crash: KASAN: use-after-free Read in jffs2_garbage_collect_pass (log)
Repro: C syz .config
  
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly jffs2 report (May 2024) 0 (1) 2024/05/16 12:44
[syzbot] [jffs2?] [nilfs?] KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass 2 (6) 2024/04/22 05:46
[syzbot] Monthly jffs2 report (Apr 2024) 0 (1) 2024/04/13 10:29
Last patch testing requests (4)
Created Duration User Patch Repo Result
2024/05/06 07:06 1h54m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/05/06 07:06 1h13m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/04/22 05:29 11m aha310510@gmail.com patch upstream report log
2024/04/22 05:10 11m aha310510@gmail.com upstream report log

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:587 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752
Read of size 8 at addr ffff88807e402130 by task jffs2_gcd_mtd0/5063

CPU: 0 PID: 5063 Comm: jffs2_gcd_mtd0 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __mutex_lock_common kernel/locking/mutex.c:587 [inline]
 __mutex_lock+0xfe/0xd70 kernel/locking/mutex.c:752
 jffs2_garbage_collect_pass+0xae/0x2120 fs/jffs2/gc.c:134
 jffs2_garbage_collect_thread+0x651/0x6e0 fs/jffs2/background.c:155
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Allocated by task 5052:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x1db/0x360 mm/slub.c:3997
 kmalloc include/linux/slab.h:628 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 jffs2_init_fs_context+0x4f/0xc0 fs/jffs2/super.c:313
 alloc_fs_context+0x68a/0x800 fs/fs_context.c:318
 do_new_mount+0x160/0xb40 fs/namespace.c:3331
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Freed by task 5052:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kfree+0x14a/0x380 mm/slub.c:4390
 deactivate_locked_super+0xc4/0x130 fs/super.c:472
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa1b/0x27e0 kernel/exit.c:878
 do_group_exit+0x207/0x2c0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

The buggy address belongs to the object at ffff88807e402000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 304 bytes inside of
 freed 4096-byte region [ffff88807e402000, ffff88807e403000)

The buggy address belongs to the physical page:
page:ffffea0001f90000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e400
head:ffffea0001f90000 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 ffff888014c42140 ffffea0000937e00 0000000000000002
raw: 0000000000000000 0000000000040004 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4727, tgid 4727 (dhcpcd), ts 35281916523, free_ts 35270327271
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
 prep_new_page mm/page_alloc.c:1540 [inline]
 get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
 __alloc_pages+0x256/0x680 mm/page_alloc.c:4569
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2175
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2391
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 __do_kmalloc_node mm/slub.c:3965 [inline]
 __kmalloc+0x2e5/0x4a0 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x255/0x500 security/tomoyo/file.c:771
 security_file_open+0x69/0x570 security/security.c:2955
 do_dentry_open+0x327/0x15a0 fs/open.c:942
 do_open fs/namei.c:3642 [inline]
 path_openat+0x2860/0x3240 fs/namei.c:3799
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_openat fs/open.c:1437 [inline]
 __se_sys_openat fs/open.c:1432 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1432
 do_syscall_64+0xfb/0x240
page last free pid 4727 tgid 4727 stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1140 [inline]
 free_unref_page_prepare+0x95d/0xa80 mm/page_alloc.c:2346
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486
 discard_slab mm/slub.c:2437 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:2906
 put_cpu_partial+0x17c/0x250 mm/slub.c:2981
 __slab_free+0x2ea/0x3d0 mm/slub.c:4151
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x174/0x340 mm/slub.c:3852
 getname_flags+0xbd/0x4f0 fs/namei.c:139
 vfs_fstatat+0x11c/0x190 fs/stat.c:303
 __do_sys_newfstatat fs/stat.c:468 [inline]
 __se_sys_newfstatat fs/stat.c:462 [inline]
 __x64_sys_newfstatat+0x117/0x190 fs/stat.c:462
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Memory state around the buggy address:
 ffff88807e402000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807e402080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807e402100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88807e402180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807e402200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/05 04:07 upstream fe46a7dd189e 0ee3535e .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/08 05:05 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 707081b61156 ca620dd8 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/05 21:50 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 707081b61156 18ea8213 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/11 15:03 upstream fe46a7dd189e 95ed9ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/11 15:03 upstream fe46a7dd189e 95ed9ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/11 15:03 upstream fe46a7dd189e 95ed9ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/11 15:02 upstream fe46a7dd189e 95ed9ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/11 15:02 upstream fe46a7dd189e 95ed9ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/08 01:47 upstream fe46a7dd189e ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/08 01:47 upstream fe46a7dd189e ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/07 09:44 upstream fe46a7dd189e ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/05 03:13 upstream fe46a7dd189e 0ee3535e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
2024/04/14 21:59 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci b5d2afe8745b c8349e48 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: slab-use-after-free Read in jffs2_garbage_collect_pass
* Struck through repros no longer work on HEAD.