From: syzbot <syzbot+675e84fdf3dde67b4946@syzkaller.appspotmail.com>
To: dwmw2@infradead.org, kartikey406@gmail.com, kees@kernel.org,
linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
richard@nod.at, syzkaller-bugs@googlegroups.com,
viro@zeniv.linux.org.uk
Subject: Re: [syzbot] [jffs2?] KASAN: invalid-free in jffs2_free_inode
Date: Sat, 26 Sep 2026 19:14:36 -0700 [thread overview]
Message-ID: <6ab87c0c.dc2998a4.2261f5.005c.GAE@google.com> (raw)
In-Reply-To: <6a8af6b0.ae6ddae5.3da009.0066.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: f5f84daefcd9 Add linux-next specific files for 20260925
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10f35a05580000
kernel config: https://syzkaller.appspot.com/x/.config?x=be00179930e43a43
dashboard link: https://syzkaller.appspot.com/bug?extid=675e84fdf3dde67b4946
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17b49315580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16e12605580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e42cbc7060af/disk-f5f84dae.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e80a7ee494ac/vmlinux-f5f84dae.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f41cc55a1308/bzImage-f5f84dae.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+675e84fdf3dde67b4946@syzkaller.appspotmail.com
RSP: 002b:00007ffed613c038 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007fa9e1225fa0 RCX: 00007fa9e0f9e159
RDX: 0000200000000080 RSI: ffffffffffffff9c RDI: 0000200000000000
RBP: 00007ffed613c0a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fa9e1225fac R14: 00007fa9e1225fa0 R15: 00007fa9e1225fa0
</TASK>
==================================================================
BUG: KASAN: double-free in jffs2_free_inode+0x41/0x60 fs/jffs2/super.c:52
Free of addr ffff8880216a6380 by task syz.0.224/6314
CPU: 0 UID: 0 PID: 6314 Comm: syz.0.224 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557
check_slab_allocation mm/kasan/common.c:-1 [inline]
__kasan_slab_pre_free+0x104/0x120 mm/kasan/common.c:272
kasan_slab_pre_free include/linux/kasan.h:199 [inline]
slab_free_hook mm/slub.c:2725 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x173/0x650 mm/slub.c:6923
jffs2_free_inode+0x41/0x60 fs/jffs2/super.c:52
i_callback fs/inode.c:318 [inline]
alloc_inode+0x17c/0x1b0 fs/inode.c:353
iget_locked+0x12c/0x690 fs/inode.c:1473
jffs2_iget+0xac/0xcc0 fs/jffs2/fs.c:265
jffs2_lookup+0x377/0x430 fs/jffs2/dir.c:114
lookup_one_qstr_excl+0x12d/0x360 fs/namei.c:1810
__start_dirop fs/namei.c:2920 [inline]
start_dirop fs/namei.c:2942 [inline]
filename_create+0x20e/0x370 fs/namei.c:5101
filename_symlinkat+0xf7/0x410 fs/namei.c:5824
__do_sys_symlinkat fs/namei.c:5850 [inline]
__se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5845
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa9e0f9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffed613c038 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007fa9e1225fa0 RCX: 00007fa9e0f9e159
RDX: 0000200000000080 RSI: ffffffffffffff9c RDI: 0000200000000000
RBP: 00007ffed613c0a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fa9e1225fac R14: 00007fa9e1225fa0 R15: 00007fa9e1225fa0
</TASK>
Allocated by task 6042:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5531 [inline]
__kmalloc_noprof+0x366/0x710 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
jffs2_do_read_inode_internal+0x4d11/0x6790 fs/jffs2/readinode.c:1271
jffs2_do_read_inode+0x4b4/0x6a0 fs/jffs2/readinode.c:1389
jffs2_iget+0x228/0xcc0 fs/jffs2/fs.c:277
jffs2_lookup+0x377/0x430 fs/jffs2/dir.c:114
lookup_one_qstr_excl+0x12d/0x360 fs/namei.c:1810
__start_dirop fs/namei.c:2920 [inline]
start_dirop fs/namei.c:2942 [inline]
filename_create+0x20e/0x370 fs/namei.c:5101
filename_symlinkat+0xf7/0x410 fs/namei.c:5824
__do_sys_symlinkat fs/namei.c:5850 [inline]
__se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5845
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 15:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:264 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2780 [inline]
slab_free mm/slub.c:6630 [inline]
kfree+0x1c5/0x650 mm/slub.c:6923
jffs2_free_inode+0x41/0x60 fs/jffs2/super.c:52
rcu_do_batch kernel/rcu/tree.c:2650 [inline]
rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919
handle_softirqs+0x223/0x840 kernel/softirq.c:645
run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099
smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff8880216a6380
which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
8-byte region [ffff8880216a6380, ffff8880216a6388)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880216a6a60 pfn:0x216a6
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88813ff24500 ffffea0000adf290 ffffea0000adaf50
raw: ffff8880216a6a60 000000000080004e 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 3479526280
set_page_owner include/linux/page_owner.h:33 [inline]
post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1854
prep_new_page mm/page_alloc.c:1862 [inline]
get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3933
__alloc_frozen_pages_noprof+0x1fc/0x400 mm/page_alloc.c:5441
alloc_slab_page mm/slub.c:3384 [inline]
allocate_slab+0x7d/0x5e0 mm/slub.c:3499
new_slab mm/slub.c:3550 [inline]
refill_objects+0x2d5/0x350 mm/slub.c:7539
refill_sheaf mm/slub.c:2917 [inline]
__pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811
alloc_from_pcs mm/slub.c:4887 [inline]
slab_alloc_node mm/slub.c:5021 [inline]
__do_kmalloc_node mm/slub.c:5530 [inline]
__kmalloc_noprof+0x476/0x710 mm/slub.c:5556
_kmalloc_noprof include/linux/slab.h:995 [inline]
acpi_ex_allocate_name_string+0x79/0x290 drivers/acpi/acpica/exnames.c:66
acpi_ex_get_name_string+0x488/0xa90 drivers/acpi/acpica/exnames.c:367
acpi_ds_create_operand+0x5c7/0xbe0 drivers/acpi/acpica/dsutils.c:446
acpi_ds_evaluate_name_path+0x1a5/0x460 drivers/acpi/acpica/dsutils.c:778
acpi_ds_exec_end_op+0x28b/0x1b00 drivers/acpi/acpica/dswexec.c:374
acpi_ps_parse_loop+0xfa3/0x23f0 drivers/acpi/acpica/psloop.c:553
acpi_ps_parse_aml+0x388/0x1020 drivers/acpi/acpica/psparse.c:489
acpi_ps_execute_method+0x89d/0xa70 drivers/acpi/acpica/psxface.c:190
acpi_ns_evaluate+0xd05/0x1320 drivers/acpi/acpica/nseval.c:205
page last free pid 1 tgid 1 ts 3320811456 stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1401 [inline]
__free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2952
__slab_free+0x269/0x2c0 mm/slub.c:5926
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_remove_cache+0x35d/0x380 mm/kasan/quarantine.c:388
kmem_cache_shrink+0xd/0x20 mm/slab_common.c:611
acpi_os_purge_cache+0x15/0x20 drivers/acpi/osl.c:1622
acpi_purge_cached_objects+0xac/0x100 drivers/acpi/acpica/utxface.c:239
acpi_initialize_objects+0x2e/0xb0 drivers/acpi/acpica/utxfinit.c:250
acpi_bus_init+0xa8/0x360 drivers/acpi/bus.c:1397
acpi_init+0xa1/0x1f0 drivers/acpi/bus.c:1486
do_one_initcall+0x250/0x870 init/main.c:1360
do_initcall_level+0x10a/0x1a0 init/main.c:1422
do_initcalls+0x59/0xa0 init/main.c:1438
kernel_init_freeable+0x29d/0x3e0 init/main.c:1673
kernel_init+0x22/0x1d0 init/main.c:1563
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
Memory state around the buggy address:
ffff8880216a6280: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
ffff8880216a6300: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
>ffff8880216a6380: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
^
ffff8880216a6400: fa fc fc fc fa fc fc fc 05 fc fc fc 05 fc fc fc
ffff8880216a6480: 05 fc fc fc 05 fc fc fc 06 fc fc fc 06 fc fc fc
==================================================================
---
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.
next prev parent reply other threads:[~2026-09-27 2:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-23 13:33 syzbot
2026-08-23 14:52 ` Forwarded: [PATCH] jffs2: fix double-free of f->target in jffs2_alloc_inode() syzbot
2026-09-27 2:14 ` syzbot [this message]
[not found] <20260823145222.16926-1-kartikey406@gmail.com>
2026-08-23 15:15 ` [syzbot] [jffs2?] KASAN: invalid-free in jffs2_free_inode syzbot
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