Re: [syzbot] [xfs?] KASAN: slab-use-after-free Read in xfs_inode_item_push

[syzbot <syzbot+1a28995e12fd13faa44e@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in xfs_inode_item_push

==================================================================
BUG: KASAN: slab-use-after-free in xfs_inode_item_push+0x293/0x2e0 fs/xfs/xfs_inode_item.c:775
Read of size 8 at addr ffff888061c9b698 by task xfsaild/loop2/7823

CPU: 1 UID: 0 PID: 7823 Comm: xfsaild/loop2 Not tainted 6.12.0-rc5-syzkaller-00181-g6c52d4da1c74 #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:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 xfs_inode_item_push+0x293/0x2e0 fs/xfs/xfs_inode_item.c:775
 xfsaild_push_item fs/xfs/xfs_trans_ail.c:395 [inline]
 xfsaild_push fs/xfs/xfs_trans_ail.c:523 [inline]
 xfsaild+0x112a/0x2e00 fs/xfs/xfs_trans_ail.c:705
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 7799:
 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:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
 xfs_inode_item_init+0x33/0xc0 fs/xfs/xfs_inode_item.c:870
 xfs_trans_ijoin+0xeb/0x130 fs/xfs/libxfs/xfs_trans_inode.c:36
 xfs_create+0x8a0/0xf60 fs/xfs/xfs_inode.c:720
 xfs_generic_create+0x5d5/0xf50 fs/xfs/xfs_iops.c:213
 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
 do_mkdirat+0x264/0x3a0 fs/namei.c:4280
 __do_sys_mkdirat fs/namei.c:4295 [inline]
 __se_sys_mkdirat fs/namei.c:4293 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
 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 6015:
 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 mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kmem_cache_free+0x1a2/0x420 mm/slub.c:4681
 xfs_inode_free_callback+0x152/0x1d0 fs/xfs/xfs_icache.c:158
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

The buggy address belongs to the object at ffff888061c9b668
 which belongs to the cache xfs_ili of size 264
The buggy address is located 48 bytes inside of
 freed 264-byte region [ffff888061c9b668, ffff888061c9b770)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x61c9b
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801d3c8dc0 ffffea00017d0300 0000000000000004
raw: 0000000000000000 00000000800c000c 00000001f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x52c50(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_RECLAIMABLE), pid 6527, tgid 6525 (syz.4.33), ts 123832632595, free_ts 120134322172
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3033/0x3180 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4141
 xfs_inode_item_init+0x33/0xc0 fs/xfs/xfs_inode_item.c:870
 xfs_trans_ijoin+0xeb/0x130 fs/xfs/libxfs/xfs_trans_inode.c:36
 xfs_create+0x8a0/0xf60 fs/xfs/xfs_inode.c:720
 xfs_generic_create+0x5d5/0xf50 fs/xfs/xfs_iops.c:213
 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
 do_mkdirat+0x264/0x3a0 fs/namei.c:4280
 __do_sys_mkdirat fs/namei.c:4295 [inline]
 __se_sys_mkdirat fs/namei.c:4293 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
page last free pid 4674 tgid 4674 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcd0/0xf00 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2677 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3145
 put_cpu_partial+0x17c/0x250 mm/slub.c:3220
 __slab_free+0x2ea/0x3d0 mm/slub.c:4449
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
 getname_flags+0xb7/0x540 fs/namei.c:139
 do_sys_openat2+0xd2/0x1d0 fs/open.c:1409
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
 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:
 ffff888061c9b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888061c9b600: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb
>ffff888061c9b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888061c9b700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff888061c9b780: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         6c52d4da Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13345340580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e9b3366c241ed3c7
dashboard link: https://syzkaller.appspot.com/bug?extid=1a28995e12fd13faa44e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.