[syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dtInsertEntry

[syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dtInsertEntry

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    e7ed34365879 Merge tag 'mailbox-v6.12' of git://git.kernel..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164e8127980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=84a3f3ed29aaafa0
dashboard link: https://syzkaller.appspot.com/bug?extid=5f7f0caf9979e9d09ff8
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eb021424c7db/disk-e7ed3436.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2f5f0d22ea96/vmlinux-e7ed3436.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47176809b11c/bzImage-e7ed3436.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5f7f0caf9979e9d09ff8@syzkaller.appspotmail.com

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:3632:9
index 27 is out of range for type 'struct lv[20]'
CPU: 1 UID: 0 PID: 5469 Comm: syz.1.37 Not tainted 6.11.0-syzkaller-12113-ge7ed34365879 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
 dtInsertEntry+0x174e/0x1780 fs/jfs/jfs_dtree.c:3632
 dtSplitPage+0x2d99/0x3ed0 fs/jfs/jfs_dtree.c:1595
 dtSplitUp fs/jfs/jfs_dtree.c:1091 [inline]
 dtInsert+0x14bd/0x6c10 fs/jfs/jfs_dtree.c:870
 jfs_create+0x7ba/0xbb0 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3595 [inline]
 open_last_lookups fs/namei.c:3694 [inline]
 path_openat+0x1c03/0x3590 fs/namei.c:3930
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_creat fs/open.c:1506 [inline]
 __se_sys_creat fs/open.c:1500 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1500
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c1f97dff9
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:00007f2c20746038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f2c1fb35f80 RCX: 00007f2c1f97dff9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000e00
RBP: 00007f2c1f9f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2c1fb35f80 R15: 00007ffdc44cf8d8
 </TASK>
---[ end trace ]---


---
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Re: [syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dtInsertEntry

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    d3d1556696c1 Merge tag 'mm-hotfixes-stable-2024-10-09-15-4..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1354cb27980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7a3fccdd0bb995
dashboard link: https://syzkaller.appspot.com/bug?extid=5f7f0caf9979e9d09ff8
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12f66fd0580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12ed005f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ea459972f07f/disk-d3d15566.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b8dcb9ab73d3/vmlinux-d3d15566.xz
kernel image: https://storage.googleapis.com/syzbot-assets/686f1b595c23/bzImage-d3d15566.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/73f0c7d76431/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5f7f0caf9979e9d09ff8@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:3624:7
index -1 is out of range for type 'struct dtslot[128]'
CPU: 0 UID: 0 PID: 5218 Comm: syz-executor135 Not tainted 6.12.0-rc2-syzkaller-00074-gd3d1556696c1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
 dtInsertEntry+0x1735/0x1780 fs/jfs/jfs_dtree.c:3624
 dtInsert+0xbc1/0x6c10 fs/jfs/jfs_dtree.c:893
 jfs_create+0x7ba/0xbb0 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3595 [inline]
 open_last_lookups fs/namei.c:3694 [inline]
 path_openat+0x1c03/0x3590 fs/namei.c:3930
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_open fs/open.c:1438 [inline]
 __se_sys_open fs/open.c:1434 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b371c0639
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff164f4418 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fff164f45f8 RCX: 00007f2b371c0639
RDX: 0000000000000000 RSI: 0000000000141042 RDI: 0000000020000000
RBP: 00007f2b37239610 R08: 0000000000005d93 R09: 0000000000000000
R10: 00007fff164f42e0 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff164f45e8 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
---[ end trace ]---


---
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.

Re: [syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dtInsertEntry

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+5f7f0caf9979e9d09ff8@syzkaller.appspotmail.com
Tested-by: syzbot+5f7f0caf9979e9d09ff8@syzkaller.appspotmail.com

Tested on:

commit:         d3d15566 Merge tag 'mm-hotfixes-stable-2024-10-09-15-4..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1126cb27980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7a3fccdd0bb995
dashboard link: https://syzkaller.appspot.com/bug?extid=5f7f0caf9979e9d09ff8
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=109a18bb980000

Note: testing is done by a robot and is best-effort only.

Forwarded: test

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: test
Author: yun.zhou@windriver.com

#syz test
diff --git a/fs/jfs/jfs_txnmgr.h b/fs/jfs/jfs_txnmgr.h
index ba71eb5ced56..391c0d28e1bc 100644
--- a/fs/jfs/jfs_txnmgr.h
+++ b/fs/jfs/jfs_txnmgr.h
@@ -165,7 +165,7 @@ struct linelock {
        u8 l2linesize;          /* 1: log2 of linesize */
        /* (8) */

-       struct lv lv[20];       /* 40: */
+       struct lv lv[]; /* 40: */
 };                             /* (48) */

 #define dt_lock        linelock

Re: [syzbot] [jfs?] UBSAN: array-index-out-of-bounds in dtInsertEntry

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in dtSplitPage

read_mapping_page failed!
ERROR: (device loop0): txCommit: 
read_mapping_page failed!
ERROR: (device loop0): txCommit: 
==================================================================
BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x121b/0x38c0 fs/jfs/jfs_dtree.c:-1
Read of size 1 at addr ffff888060f891dd by task syz.0.16/6471

CPU: 0 UID: 0 PID: 6471 Comm: syz.0.16 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 dtSplitPage+0x121b/0x38c0 fs/jfs/jfs_dtree.c:-1
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x100c/0x5d10 fs/jfs/jfs_dtree.c:871
 jfs_mkdir+0x6ec/0xa70 fs/jfs/namei.c:270
 vfs_mkdir+0x306/0x510 fs/namei.c:4453
 do_mkdirat+0x247/0x590 fs/namei.c:4486
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8cecf8d1d7
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 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:00007f8cede76e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f8cede76ef0 RCX: 00007f8cecf8d1d7
RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000140 R08: 00002000000000c0 R09: 0000000000000000
R10: 0000200000000140 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f8cede76eb0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 6471:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:342 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4978 [inline]
 slab_alloc_node mm/slub.c:5288 [inline]
 kmem_cache_alloc_lru_noprof+0x35d/0x6d0 mm/slub.c:5307
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x6a/0x1b0 fs/inode.c:346
 iget_locked+0x106/0x580 fs/inode.c:1445
 jfs_iget+0x24/0x470 fs/jfs/inode.c:29
 jfs_lookup+0x1c5/0x380 fs/jfs/namei.c:1469
 __lookup_slow+0x297/0x3d0 fs/namei.c:1816
 lookup_slow+0x53/0x70 fs/namei.c:1833
 walk_component+0x2d2/0x400 fs/namei.c:2151
 lookup_last fs/namei.c:2652 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2676
 filename_lookup+0x212/0x570 fs/namei.c:2705
 user_path_at+0x3a/0x60 fs/namei.c:3215
 __do_sys_chdir fs/open.c:561 [inline]
 __se_sys_chdir+0x91/0x280 fs/open.c:555
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888060f88928
 which belongs to the cache jfs_ip of size 2216
The buggy address is located 13 bytes to the right of
 allocated 2216-byte region [ffff888060f88928, ffff888060f891d0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x60f88
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888077ec2e01
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801e397280 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800d000d 00000000f5000000 ffff888077ec2e01
head: 00fff00000000040 ffff88801e397280 dead000000000122 0000000000000000
head: 0000000000000000 00000000800d000d 00000000f5000000 ffff888077ec2e01
head: 00fff00000000003 ffffea000183e201 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_RECLAIMABLE|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6471, tgid 6470 (syz.0.16), ts 129317552975, free_ts 22248192864
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x2356/0x2430 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3059 [inline]
 allocate_slab+0x96/0x350 mm/slub.c:3232
 new_slab mm/slub.c:3286 [inline]
 ___slab_alloc+0xf56/0x1990 mm/slub.c:4655
 __slab_alloc+0x65/0x100 mm/slub.c:4778
 __slab_alloc_node mm/slub.c:4854 [inline]
 slab_alloc_node mm/slub.c:5276 [inline]
 kmem_cache_alloc_lru_noprof+0x3ef/0x6d0 mm/slub.c:5307
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x6a/0x1b0 fs/inode.c:346
 iget_locked+0x106/0x580 fs/inode.c:1445
 jfs_iget+0x24/0x470 fs/jfs/inode.c:29
 jfs_fill_super+0x8ad/0xd80 fs/jfs/super.c:547
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1698
 vfs_get_tree+0x92/0x2b0 fs/super.c:1758
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3642 [inline]
 do_new_mount+0x302/0xa10 fs/namespace.c:3718
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0xbb1/0xd20 mm/page_alloc.c:2906
 __free_pages mm/page_alloc.c:5302 [inline]
 free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:7146
 destroy_args+0x69/0x660 mm/debug_vm_pgtable.c:958
 debug_vm_pgtable+0x39f/0x3b0 mm/debug_vm_pgtable.c:1345
 do_one_initcall+0x236/0x820 init/main.c:1283
 do_initcall_level+0x104/0x190 init/main.c:1345
 do_initcalls+0x59/0xa0 init/main.c:1361
 kernel_init_freeable+0x334/0x4b0 init/main.c:1593
 kernel_init+0x1d/0x1d0 init/main.c:1483
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff888060f89080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888060f89100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888060f89180: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                    ^
 ffff888060f89200: fc fc fc fc fc fc fc fc fc fc 00 00 00 00 00 00
 ffff888060f89280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


Tested on:

commit:         e7c375b1 Merge tag 'vfs-6.18-rc7.fixes' of gitolite.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ca3914580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=38deb25bbc2fa41e
dashboard link: https://syzkaller.appspot.com/bug?extid=5f7f0caf9979e9d09ff8
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=110df212580000