Message-ID: <CAJD7tkZLGFhHYoZ2hceq0nF2H0i=nZxPRr60uA0WgwcVnk4H5w@mail.gmail.com>
Date: Mon, 13 Jan 2025 11:00:13 -0800
From: Yosry Ahmed <yosryahmed@...gle.com>
To: syzbot <syzbot+7c26f5c5ca6a61056049@...kaller.appspotmail.com>
Cc: akpm@...ux-foundation.org, chengming.zhou@...ux.dev, hannes@...xchg.org, 
	linux-kernel@...r.kernel.org, linux-mm@...ck.org, nphamcs@...il.com, 
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [mm?] KASAN: slab-use-after-free Write in zswap_store

On Mon, Dec 23, 2024 at 12:37 AM syzbot
<syzbot+7c26f5c5ca6a61056049@...kaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    48f506ad0b68 Merge tag 'soc-fixes-6.13-2' of git://git.ker..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13649fe8580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=c22efbd20f8da769
> dashboard link: https://syzkaller.appspot.com/bug?extid=7c26f5c5ca6a61056049
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, 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/f42f936a7d8d/disk-48f506ad.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/5f5d9512f350/vmlinux-48f506ad.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/08855819fbb0/bzImage-48f506ad.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+7c26f5c5ca6a61056049@...kaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in acomp_request_set_params include/crypto/acompress.h:230 [inline]
> BUG: KASAN: slab-use-after-free in zswap_compress mm/zswap.c:910 [inline]
> BUG: KASAN: slab-use-after-free in zswap_store_page mm/zswap.c:1426 [inline]
> BUG: KASAN: slab-use-after-free in zswap_store+0x2481/0x25d0 mm/zswap.c:1533
> Write of size 8 at addr ffff8880344bc330 by task syz.2.518/8050
>
> CPU: 0 UID: 0 PID: 8050 Comm: syz.2.518 Not tainted 6.13.0-rc3-syzkaller-00289-g48f506ad0b68 #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+0x116/0x1f0 lib/dump_stack.c:120
>  print_address_description mm/kasan/report.c:378 [inline]
>  print_report+0xc3/0x620 mm/kasan/report.c:489
>  kasan_report+0xd9/0x110 mm/kasan/report.c:602
>  acomp_request_set_params include/crypto/acompress.h:230 [inline]
>  zswap_compress mm/zswap.c:910 [inline]
>  zswap_store_page mm/zswap.c:1426 [inline]
>  zswap_store+0x2481/0x25d0 mm/zswap.c:1533
>  swap_writepage+0x3b6/0x1120 mm/page_io.c:279
>  shmem_writepage+0xf76/0x1490 mm/shmem.c:1579
>  pageout+0x3b2/0xaa0 mm/vmscan.c:689
>  shrink_folio_list+0x3025/0x42d0 mm/vmscan.c:1367
>  evict_folios+0x6e3/0x19c0 mm/vmscan.c:4593
>  try_to_shrink_lruvec+0x61e/0xa80 mm/vmscan.c:4789
>  lru_gen_shrink_lruvec mm/vmscan.c:4938 [inline]
>  shrink_lruvec+0x313/0x2ba0 mm/vmscan.c:5693
>  shrink_node_memcgs mm/vmscan.c:5929 [inline]
>  shrink_node mm/vmscan.c:5970 [inline]
>  shrink_node+0x105e/0x3f20 mm/vmscan.c:5948
>  shrink_zones mm/vmscan.c:6215 [inline]
>  do_try_to_free_pages+0x35f/0x1a30 mm/vmscan.c:6277
>  try_to_free_mem_cgroup_pages+0x31a/0x7a0 mm/vmscan.c:6609
>  try_charge_memcg+0x356/0xaf0 mm/memcontrol.c:2238
>  try_charge mm/memcontrol-v1.h:19 [inline]
>  charge_memcg mm/memcontrol.c:4497 [inline]
>  __mem_cgroup_charge+0x9b/0x280 mm/memcontrol.c:4512
>  mem_cgroup_charge include/linux/memcontrol.h:646 [inline]
>  shmem_alloc_and_add_folio+0x507/0xc00 mm/shmem.c:1847
>  shmem_get_folio_gfp+0x689/0x1530 mm/shmem.c:2357
>  shmem_get_folio mm/shmem.c:2463 [inline]
>  shmem_write_begin+0x161/0x300 mm/shmem.c:3119
>  generic_perform_write+0x2ba/0x920 mm/filemap.c:4055
>  shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3295
>  __kernel_write_iter+0x318/0xa80 fs/read_write.c:612
>  dump_emit_page fs/coredump.c:884 [inline]
>  dump_user_range+0x389/0x8c0 fs/coredump.c:945
>  elf_core_dump+0x2787/0x3880 fs/binfmt_elf.c:2129
>  do_coredump+0x2dd5/0x43e0 fs/coredump.c:758
>  get_signal+0x23f3/0x2610 kernel/signal.c:3002
>  arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
>  exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
>  exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
>  irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
>  asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
> RIP: 0033:0x100000
> Code: Unable to access opcode bytes at 0xfffd6.
> RSP: 002b:000000000000000a EFLAGS: 00010217
> RAX: 0000000000000000 RBX: 00007fe556775fa0 RCX: 00007fe556585d29
> RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
> RBP: 00007fe556601aa8 R08: 0000000000000200 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000000000 R14: 00007fe556775fa0 R15: 00007ffc3d0ee328
>  </TASK>
>
> Allocated by task 1:
>  kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
>  kasan_save_track+0x14/0x30 mm/kasan/common.c:68
>  poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
>  __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
>  kasan_kmalloc include/linux/kasan.h:260 [inline]
>  __do_kmalloc_node mm/slub.c:4298 [inline]
>  __kmalloc_noprof+0x21a/0x4f0 mm/slub.c:4310
>  kmalloc_noprof include/linux/slab.h:905 [inline]
>  kzalloc_noprof include/linux/slab.h:1037 [inline]
>  __acomp_request_alloc_noprof include/crypto/internal/acompress.h:75 [inline]
>  acomp_request_alloc+0x46/0x110 crypto/acompress.c:131
>  zswap_cpu_comp_prepare+0x1f2/0x460 mm/zswap.c:840
>  cpuhp_invoke_callback+0x20c/0xa10 kernel/cpu.c:204
>  cpuhp_issue_call+0x1c0/0x980 kernel/cpu.c:2375
>  __cpuhp_state_add_instance_cpuslocked+0x1a4/0x3c0 kernel/cpu.c:2437
>  __cpuhp_state_add_instance+0xd7/0x2e0 kernel/cpu.c:2458
>  cpuhp_state_add_instance include/linux/cpuhotplug.h:386 [inline]
>  zswap_pool_create+0x27b/0x540 mm/zswap.c:288
>  __zswap_pool_create_fallback mm/zswap.c:356 [inline]
>  zswap_setup+0x402/0x810 mm/zswap.c:1781
>  zswap_init+0x2c/0x40 mm/zswap.c:1817
>  do_one_initcall+0x128/0x630 init/main.c:1266
>  do_initcall_level init/main.c:1328 [inline]
>  do_initcalls init/main.c:1344 [inline]
>  do_basic_setup init/main.c:1363 [inline]
>  kernel_init_freeable+0x58f/0x8b0 init/main.c:1577
>  kernel_init+0x1c/0x2b0 init/main.c:1466
>  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> Freed by task 5898:
>  kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
>  kasan_save_track+0x14/0x30 mm/kasan/common.c:68
>  kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:582
>  poison_slab_object mm/kasan/common.c:247 [inline]
>  __kasan_slab_free+0x51/0x70 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]
>  kfree+0x14f/0x4b0 mm/slub.c:4761
>  zswap_cpu_comp_dead+0xe3/0x1c0 mm/zswap.c:874
>  cpuhp_invoke_callback+0x528/0xa10 kernel/cpu.c:216
>  __cpuhp_invoke_callback_range+0x101/0x200 kernel/cpu.c:965
>  cpuhp_invoke_callback_range kernel/cpu.c:989 [inline]
>  cpuhp_down_callbacks kernel/cpu.c:1382 [inline]
>  _cpu_down+0x422/0xf20 kernel/cpu.c:1443
>  __cpu_down_maps_locked+0x6c/0x90 kernel/cpu.c:1473
>  work_for_cpu_fn+0x52/0xa0 kernel/workqueue.c:6719
>  process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
>  process_scheduled_works kernel/workqueue.c:3310 [inline]
>  worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
>  kthread+0x2c1/0x3a0 kernel/kthread.c:389
>  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> The buggy address belongs to the object at ffff8880344bc300
>  which belongs to the cache kmalloc-96 of size 96
> The buggy address is located 48 bytes inside of
>  freed 96-byte region [ffff8880344bc300, ffff8880344bc360)
>
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x344bc
> anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 00fff00000000000 ffff88801ac41280 0000000000000000 dead000000000001
> raw: 0000000000000000 0000000000200020 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1, tgid 1 (swapper/0), ts 20977470907, free_ts 20711170276
>  set_page_owner include/linux/page_owner.h:32 [inline]
>  post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1558
>  prep_new_page mm/page_alloc.c:1566 [inline]
>  get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3476
>  __alloc_pages_noprof+0x223/0x25b0 mm/page_alloc.c:4753
>  __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
>  alloc_slab_page mm/slub.c:2425 [inline]
>  allocate_slab mm/slub.c:2589 [inline]
>  new_slab+0xca/0x410 mm/slub.c:2642
>  ___slab_alloc+0xce2/0x1650 mm/slub.c:3830
>  __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3920
>  __slab_alloc_node mm/slub.c:3995 [inline]
>  slab_alloc_node mm/slub.c:4156 [inline]
>  __kmalloc_cache_node_noprof+0xfb/0x3f0 mm/slub.c:4337
>  kmalloc_node_noprof include/linux/slab.h:924 [inline]
>  alloc_node_nr_active kernel/workqueue.c:4859 [inline]
>  __alloc_workqueue+0x506/0x1810 kernel/workqueue.c:5712
>  alloc_workqueue+0xd3/0x200 kernel/workqueue.c:5772
>  zswap_setup+0xcb/0x810 mm/zswap.c:1767
>  zswap_init+0x2c/0x40 mm/zswap.c:1817
>  do_one_initcall+0x128/0x630 init/main.c:1266
>  do_initcall_level init/main.c:1328 [inline]
>  do_initcalls init/main.c:1344 [inline]
>  do_basic_setup init/main.c:1363 [inline]
>  kernel_init_freeable+0x58f/0x8b0 init/main.c:1577
>  kernel_init+0x1c/0x2b0 init/main.c:1466
>  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
> page last free pid 8 tgid 8 stack trace:
>  reset_page_owner include/linux/page_owner.h:25 [inline]
>  free_pages_prepare mm/page_alloc.c:1127 [inline]
>  free_unref_page+0x661/0x1080 mm/page_alloc.c:2659
>  vfree+0x174/0x950 mm/vmalloc.c:3383
>  delayed_vfree_work+0x56/0x70 mm/vmalloc.c:3303
>  process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
>  process_scheduled_works kernel/workqueue.c:3310 [inline]
>  worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
>  kthread+0x2c1/0x3a0 kernel/kthread.c:389
>  ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> Memory state around the buggy address:
>  ffff8880344bc200: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
>  ffff8880344bc280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
> >ffff8880344bc300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>                                      ^
>  ffff8880344bc380: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
>  ffff8880344bc400: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@...glegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title

#syz fix "mm: zswap: properly synchronize freeing resources during CPU
hotunplug"

>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup

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