Message-ID: <000000000000041f960618206d7e@google.com>
Date: Fri, 10 May 2024 14:43:27 -0700
From: syzbot <syzbot+1527696d41a634cc1819@...kaller.appspotmail.com>
To: asmadeus@...ewreck.org, ericvh@...nel.org, linux-kernel@...r.kernel.org, 
	linux_oss@...debyte.com, lucho@...kov.net, syzkaller-bugs@...glegroups.com, 
	v9fs@...ts.linux.dev
Subject: [syzbot] [v9fs?] KASAN: slab-use-after-free Read in p9_client_destroy

Hello,

syzbot found the following issue on:

HEAD commit:    f4345f05c0df Merge tag 'block-6.9-20240510' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=122bfdb8980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9d7ea7de0cb32587
dashboard link: https://syzkaller.appspot.com/bug?extid=1527696d41a634cc1819
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/1dc00463a49c/disk-f4345f05.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/137d9071f058/vmlinux-f4345f05.xz
kernel image: https://storage.googleapis.com/syzbot-assets/77a30b1a7a80/bzImage-f4345f05.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1527696d41a634cc1819@...kaller.appspotmail.com

9pnet: Found fid 1 not clunked
==================================================================
BUG: KASAN: slab-use-after-free in p9_fid_destroy net/9p/client.c:884 [inline]
BUG: KASAN: slab-use-after-free in p9_client_destroy+0x183/0x660 net/9p/client.c:1070
Read of size 8 at addr ffff88801e478d00 by task syz-executor.2/14884

CPU: 1 PID: 14884 Comm: syz-executor.2 Not tainted 6.9.0-rc7-syzkaller-00136-gf4345f05c0df #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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
 p9_fid_destroy net/9p/client.c:884 [inline]
 p9_client_destroy+0x183/0x660 net/9p/client.c:1070
 v9fs_session_close+0x51/0x210 fs/9p/v9fs.c:506
 v9fs_kill_super+0x5c/0x90 fs/9p/vfs_super.c:196
 deactivate_locked_super+0xc4/0x130 fs/super.c:472
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b3347f097
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff26a7f1a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f9b3347f097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff26a7f260
RBP: 00007fff26a7f260 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff26a80320
R13: 00007f9b334c9336 R14: 00000000000a0428 R15: 000000000000000b
 </TASK>

Allocated by task 16717:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace+0x1db/0x370 mm/slub.c:4003
 kmalloc include/linux/slab.h:628 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 p9_fid_create+0x4f/0x230 net/9p/client.c:853
 p9_client_walk+0x103/0x690 net/9p/client.c:1154
 clone_fid fs/9p/fid.h:23 [inline]
 v9fs_fid_clone fs/9p/fid.h:33 [inline]
 v9fs_file_open+0x285/0xa60 fs/9p/vfs_file.c:56
 do_dentry_open+0x907/0x15a0 fs/open.c:955
 do_open fs/namei.c:3642 [inline]
 path_openat+0x2860/0x3240 fs/namei.c:3799
 do_filp_open+0x235/0x490 fs/namei.c:3826
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
 do_sys_open fs/open.c:1421 [inline]
 __do_sys_creat fs/open.c:1497 [inline]
 __se_sys_creat fs/open.c:1491 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1491
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 140:
 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+0xa6/0xe0 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2111 [inline]
 slab_free mm/slub.c:4286 [inline]
 kfree+0x153/0x3b0 mm/slub.c:4396
 p9_fid_destroy net/9p/client.c:889 [inline]
 p9_client_clunk+0x1ce/0x260 net/9p/client.c:1456
 netfs_free_request+0x244/0x600 fs/netfs/objects.c:97
 v9fs_upload_to_server fs/9p/vfs_addr.c:36 [inline]
 v9fs_upload_to_server_worker+0x200/0x3e0 fs/9p/vfs_addr.c:44
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/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 ffff88801e478d00
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 freed 96-byte region [ffff88801e478d00, ffff88801e478d60)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1e478
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888015041780 ffffea0000b68440 dead000000000002
raw: 0000000000000000 0000000000200020 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5148, tgid 2075898714 (kworker/0:5), ts 5148, free_ts 79305822594
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2180
 allocate_slab mm/slub.c:2343 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2396
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3530
 __slab_alloc mm/slub.c:3615 [inline]
 __slab_alloc_node mm/slub.c:3668 [inline]
 slab_alloc_node mm/slub.c:3841 [inline]
 kmalloc_trace+0x269/0x370 mm/slub.c:3998
 kmalloc include/linux/slab.h:628 [inline]
 kzalloc include/linux/slab.h:749 [inline]
 nsim_fib6_rt_create drivers/net/netdevsim/fib.c:547 [inline]
 nsim_fib6_rt_insert drivers/net/netdevsim/fib.c:752 [inline]
 nsim_fib6_event drivers/net/netdevsim/fib.c:856 [inline]
 nsim_fib_event drivers/net/netdevsim/fib.c:889 [inline]
 nsim_fib_event_work+0x19c2/0x4130 drivers/net/netdevsim/fib.c:1492
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 927 tgid 927 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x97b/0xaa0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 discard_slab mm/slub.c:2442 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:2911
 put_cpu_partial+0x17c/0x250 mm/slub.c:2986
 __slab_free+0x2ea/0x3d0 mm/slub.c:4157
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3804 [inline]
 slab_alloc_node mm/slub.c:3851 [inline]
 kmem_cache_alloc+0x174/0x350 mm/slub.c:3858
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 xfs_trans_alloc+0x81/0x830 fs/xfs/xfs_trans.c:262
 xfs_setfilesize+0xd7/0x4e0 fs/xfs/xfs_aops.c:58
 xfs_end_ioend+0x317/0x470 fs/xfs/xfs_aops.c:134
 xfs_end_io+0x2e5/0x380 fs/xfs/xfs_aops.c:173
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388

Memory state around the buggy address:
 ffff88801e478c00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88801e478c80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88801e478d00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff88801e478d80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88801e478e00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
==================================================================


---
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