Message-ID: <677603a1.050a0220.3a8527.0034.GAE@google.com>
Date: Wed, 01 Jan 2025 19:10:25 -0800
From: syzbot <syzbot+a98891ce2318fe7baf05@...kaller.appspotmail.com>
To: jfs-discussion@...ts.sourceforge.net, linux-kernel@...r.kernel.org, 
	shaggy@...nel.org, syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [jfs?] KASAN: slab-use-after-free Read in jfs_readdir

syzbot has found a reproducer for the following issue on:

HEAD commit:    56e6a3499e14 Merge tag 'trace-v6.13-rc5' of git://git.kern..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1765b818580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ba7cde9482d6bb6
dashboard link: https://syzkaller.appspot.com/bug?extid=a98891ce2318fe7baf05
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=126136df980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=171d3af8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e5f33d8e3542/disk-56e6a349.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b53906ddb840/vmlinux-56e6a349.xz
kernel image: https://storage.googleapis.com/syzbot-assets/115963cd9410/bzImage-56e6a349.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/b0dae106c522/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a98891ce2318fe7baf05@...kaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in jfs_readdir+0x1361/0x3c50 fs/jfs/jfs_dtree.c:2869
Read of size 8 at addr ffff88807510a128 by task syz-executor140/5820

CPU: 0 UID: 0 PID: 5820 Comm: syz-executor140 Not tainted 6.13.0-rc5-syzkaller-00006-g56e6a3499e14 #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
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 jfs_readdir+0x1361/0x3c50 fs/jfs/jfs_dtree.c:2869
 wrap_directory_iterator+0x91/0xd0 fs/readdir.c:65
 iterate_dir+0x571/0x800 fs/readdir.c:108
 __do_sys_getdents fs/readdir.c:322 [inline]
 __se_sys_getdents+0x1fd/0x4e0 fs/readdir.c:308
 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: 0033:0x7f5da6b29199
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 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:00007ffef1871898 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5da6b29199
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007ffef18718d0 R09: 00007ffef18718d0
R10: 00007ffef18718d0 R11: 0000000000000246 R12: 00007ffef18718d0
R13: 00007ffef1871b58 R14: 431bde82d7b634db R15: 00007f5da6b7203b
 </TASK>

Allocated by task 5820:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175
 mempool_alloc_noprof+0x197/0x5a0 mm/mempool.c:402
 alloc_metapage fs/jfs/jfs_metapage.c:182 [inline]
 __get_metapage+0x5f4/0xdc0 fs/jfs/jfs_metapage.c:652
 dtSplitRoot+0x2af/0x1930 fs/jfs/jfs_dtree.c:1909
 dtSplitUp fs/jfs/jfs_dtree.c:992 [inline]
 dtInsert+0x12cd/0x6c10 fs/jfs/jfs_dtree.c:870
 jfs_mkdir+0x7fb/0xba0 fs/jfs/namei.c:270
 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4311
 do_mkdirat+0x264/0x3a0 fs/namei.c:4334
 __do_sys_mkdir fs/namei.c:4354 [inline]
 __se_sys_mkdir fs/namei.c:4352 [inline]
 __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4352
 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

Freed by task 5820:
 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:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kmem_cache_free+0x195/0x410 mm/slub.c:4715
 free_metapage fs/jfs/jfs_metapage.c:197 [inline]
 drop_metapage fs/jfs/jfs_metapage.c:234 [inline]
 release_metapage+0x831/0xa90 fs/jfs/jfs_metapage.c:784
 dtReadNext fs/jfs/jfs_dtree.c:3189 [inline]
 jfs_readdir+0x102d/0x3c50 fs/jfs/jfs_dtree.c:2862
 wrap_directory_iterator+0x91/0xd0 fs/readdir.c:65
 iterate_dir+0x571/0x800 fs/readdir.c:108
 __do_sys_getdents fs/readdir.c:322 [inline]
 __se_sys_getdents+0x1fd/0x4e0 fs/readdir.c:308
 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

The buggy address belongs to the object at ffff88807510a0f8
 which belongs to the cache jfs_mp of size 184
The buggy address is located 48 bytes inside of
 freed 184-byte region [ffff88807510a0f8, ffff88807510a1b0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7510a
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff8881476dc8c0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000001f5000000 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 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5820, tgid 5820 (syz-executor140), ts 62287500316, free_ts 55275390556
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269
 alloc_slab_page+0x6a/0x110 mm/slub.c:2423
 allocate_slab+0x5a/0x2b0 mm/slub.c:2589
 new_slab mm/slub.c:2642 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830
 __slab_alloc+0x58/0xa0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4175
 mempool_alloc_noprof+0x197/0x5a0 mm/mempool.c:402
 alloc_metapage fs/jfs/jfs_metapage.c:182 [inline]
 __get_metapage+0x5f4/0xdc0 fs/jfs/jfs_metapage.c:652
 ea_get+0xb6f/0x12e0 fs/jfs/xattr.c:528
 __jfs_setxattr+0x4ba/0x1190 fs/jfs/xattr.c:722
 jfs_initxattrs+0x128/0x1d0 fs/jfs/xattr.c:1035
 security_inode_init_security+0x29c/0x480 security/security.c:1847
 jfs_init_security+0xa9/0x110 fs/jfs/xattr.c:1047
page last free pid 5809 tgid 5809 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xd2c/0x1000 mm/page_alloc.c:2659
 __folio_put+0x2b3/0x360 mm/swap.c:112
 pipe_buf_release include/linux/pipe_fs_i.h:219 [inline]
 pipe_update_tail fs/pipe.c:224 [inline]
 pipe_read+0x6ed/0x13e0 fs/pipe.c:344
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x991/0xb70 fs/read_write.c:565
 ksys_read+0x18f/0x2b0 fs/read_write.c:708
 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

Memory state around the buggy address:
 ffff88807510a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807510a080: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fa
>ffff88807510a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88807510a180: fb fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00
 ffff88807510a200: 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.

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