Hello,
syzbot found the following issue on:
HEAD commit: 8d2be868b42c Add linux-next specific files for 20230623
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12872950a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=d8ac8dd33677e8e0
dashboard link: https://syzkaller.appspot.com/bug?extid=8540db210d403f1aa214
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1b70f280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122ee4cb280000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2a004483aca3/disk-8d2be868.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5688cb13b277/vmlinux-8d2be868.xz
kernel image: https://storage.googleapis.com/syzbot-assets/76de0b63bc53/bzImage-8d2be868.xz
The issue was bisected to:
commit 21a18f4a51896fde11002165f0e7340f4131d6a0
Author: Mike Christie <[email protected]>
Date: Tue Jun 13 01:32:46 2023 +0000
vhost: allow userspace to create workers
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=130850bf280000
final oops: https://syzkaller.appspot.com/x/report.txt?x=108850bf280000
console output: https://syzkaller.appspot.com/x/log.txt?x=170850bf280000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]
Fixes: 21a18f4a5189 ("vhost: allow userspace to create workers")
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:582 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0x1029/0x1350 kernel/locking/mutex.c:747
Read of size 8 at addr ffff8880703fff68 by task syz-executor204/5105
CPU: 0 PID: 5105 Comm: syz-executor204 Not tainted 6.4.0-rc7-next-20230623-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:364
print_report mm/kasan/report.c:475 [inline]
kasan_report+0x11d/0x130 mm/kasan/report.c:588
__mutex_lock_common kernel/locking/mutex.c:582 [inline]
__mutex_lock+0x1029/0x1350 kernel/locking/mutex.c:747
__vhost_vq_attach_worker+0xe7/0x390 drivers/vhost/vhost.c:678
vhost_dev_set_owner+0x670/0xa60 drivers/vhost/vhost.c:892
vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
vhost_net_ioctl+0x668/0x16a0 drivers/vhost/net.c:1737
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fe7a9715629
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 19 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:00007fe7a96ba208 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007fe7a9715629
RDX: 0000000000000000 RSI: 000000000000af01 RDI: 0000000000000003
RBP: 00007fe7a979e240 R08: 00007fe7a979e248 R09: 00007fe7a979e248
R10: 00007fe7a979e248 R11: 0000000000000246 R12: 00007fe7a979e24c
R13: 00007ffcfa04d48f R14: 00007fe7a96ba300 R15: 0000000000022000
</TASK>
Allocated by task 5105:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
____kasan_kmalloc mm/kasan/common.c:333 [inline]
__kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383
kmalloc include/linux/slab.h:579 [inline]
kzalloc include/linux/slab.h:700 [inline]
vhost_worker_create+0x9c/0x320 drivers/vhost/vhost.c:627
vhost_dev_set_owner+0x5b9/0xa60 drivers/vhost/vhost.c:885
vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
vhost_net_ioctl+0x668/0x16a0 drivers/vhost/net.c:1737
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 5108:
kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:521
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1792 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1818
slab_free mm/slub.c:3801 [inline]
__kmem_cache_free+0xb8/0x2d0 mm/slub.c:3814
vhost_worker_destroy drivers/vhost/vhost.c:600 [inline]
vhost_workers_free drivers/vhost/vhost.c:615 [inline]
vhost_dev_cleanup+0x66b/0x850 drivers/vhost/vhost.c:991
vhost_dev_reset_owner+0x25/0x160 drivers/vhost/vhost.c:923
vhost_net_reset_owner drivers/vhost/net.c:1621 [inline]
vhost_net_ioctl+0x807/0x16a0 drivers/vhost/net.c:1735
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The buggy address belongs to the object at ffff8880703fff00
which belongs to the cache kmalloc-cg-192 of size 192
The buggy address is located 104 bytes inside of
freed 192-byte region [ffff8880703fff00, ffff8880703fffc0)
The buggy address belongs to the physical page:
page:ffffea0001c0ffc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x703ff
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000200 ffff88801284ddc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 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 0x16cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY), pid 5034, tgid 5034 (syz-executor204), ts 72916757418, free_ts 72797036103
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1570
prep_new_page mm/page_alloc.c:1577 [inline]
get_page_from_freelist+0xfd9/0x2c40 mm/page_alloc.c:3257
__alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4513
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279
alloc_slab_page mm/slub.c:1862 [inline]
allocate_slab+0x25f/0x390 mm/slub.c:2009
new_slab mm/slub.c:2062 [inline]
___slab_alloc+0xbc3/0x15d0 mm/slub.c:3215
__slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314
__slab_alloc_node mm/slub.c:3367 [inline]
slab_alloc_node mm/slub.c:3460 [inline]
__kmem_cache_alloc_node+0x143/0x350 mm/slub.c:3509
__do_kmalloc_node mm/slab_common.c:984 [inline]
__kmalloc_node+0x51/0x1a0 mm/slab_common.c:992
kmalloc_node include/linux/slab.h:599 [inline]
kvmalloc_node+0xa2/0x1a0 mm/util.c:604
kvmalloc include/linux/slab.h:717 [inline]
kvzalloc include/linux/slab.h:725 [inline]
netif_alloc_rx_queues net/core/dev.c:9847 [inline]
alloc_netdev_mqs+0xbde/0x1270 net/core/dev.c:10660
ieee80211_if_add+0x1b7/0x19d0 net/mac80211/iface.c:2099
ieee80211_register_hw+0x37e5/0x40e0 net/mac80211/main.c:1407
mac80211_hwsim_new_radio+0x26e6/0x4c70 drivers/net/wireless/virtual/mac80211_hwsim.c:5303
hwsim_new_radio_nl+0xacf/0x1210 drivers/net/wireless/virtual/mac80211_hwsim.c:5983
genl_family_rcv_msg_doit.isra.0+0x1e6/0x2d0 net/netlink/genetlink.c:970
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1161 [inline]
free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2384
free_unref_page+0x33/0x370 mm/page_alloc.c:2479
__unfreeze_partials+0x1fe/0x220 mm/slub.c:2647
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:750 [inline]
slab_alloc_node mm/slub.c:3470 [inline]
__kmem_cache_alloc_node+0x1ce/0x350 mm/slub.c:3509
__do_kmalloc_node mm/slab_common.c:984 [inline]
__kmalloc_node+0x51/0x1a0 mm/slab_common.c:992
kmalloc_node include/linux/slab.h:599 [inline]
kvmalloc_node+0xa2/0x1a0 mm/util.c:604
kvmalloc include/linux/slab.h:717 [inline]
seq_buf_alloc fs/seq_file.c:38 [inline]
seq_read_iter+0x7fb/0x12d0 fs/seq_file.c:210
kernfs_fop_read_iter+0x4ce/0x690 fs/kernfs/file.c:279
call_read_iter include/linux/fs.h:1865 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x4a8/0x8d0 fs/read_write.c:470
ksys_read+0x122/0x250 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Memory state around the buggy address:
ffff8880703ffe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880703ffe80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff8880703fff00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880703fff80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
ffff888070400000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This report is generated by a bot. It may contain errors.
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syzbot engineers can be reached at [email protected].
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title
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.
If you want to change bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
On Mon, Jun 26, 2023 at 12:06:54AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 8d2be868b42c Add linux-next specific files for 20230623
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12872950a80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=d8ac8dd33677e8e0
> dashboard link: https://syzkaller.appspot.com/bug?extid=8540db210d403f1aa214
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1b70f280000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122ee4cb280000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/2a004483aca3/disk-8d2be868.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/5688cb13b277/vmlinux-8d2be868.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/76de0b63bc53/bzImage-8d2be868.xz
>
> The issue was bisected to:
>
> commit 21a18f4a51896fde11002165f0e7340f4131d6a0
> Author: Mike Christie <[email protected]>
> Date: Tue Jun 13 01:32:46 2023 +0000
>
> vhost: allow userspace to create workers
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=130850bf280000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=108850bf280000
> console output: https://syzkaller.appspot.com/x/log.txt?x=170850bf280000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: [email protected]
> Fixes: 21a18f4a5189 ("vhost: allow userspace to create workers")
Mike, would appreciate prompt attention to this as I am preparing
a pull request for the merge window and need to make a
decision on whether to include your userspace-controlled
threading patchset.
Thanks!
> ==================================================================
> BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:582 [inline]
> BUG: KASAN: slab-use-after-free in __mutex_lock+0x1029/0x1350 kernel/locking/mutex.c:747
> Read of size 8 at addr ffff8880703fff68 by task syz-executor204/5105
>
> CPU: 0 PID: 5105 Comm: syz-executor204 Not tainted 6.4.0-rc7-next-20230623-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
> Call Trace:
> <TASK>
> __dump_stack lib/dump_stack.c:88 [inline]
> dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
> print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:364
> print_report mm/kasan/report.c:475 [inline]
> kasan_report+0x11d/0x130 mm/kasan/report.c:588
> __mutex_lock_common kernel/locking/mutex.c:582 [inline]
> __mutex_lock+0x1029/0x1350 kernel/locking/mutex.c:747
> __vhost_vq_attach_worker+0xe7/0x390 drivers/vhost/vhost.c:678
> vhost_dev_set_owner+0x670/0xa60 drivers/vhost/vhost.c:892
> vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
> vhost_net_ioctl+0x668/0x16a0 drivers/vhost/net.c:1737
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:870 [inline]
> __se_sys_ioctl fs/ioctl.c:856 [inline]
> __x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:856
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7fe7a9715629
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 19 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:00007fe7a96ba208 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00007fe7a9715629
> RDX: 0000000000000000 RSI: 000000000000af01 RDI: 0000000000000003
> RBP: 00007fe7a979e240 R08: 00007fe7a979e248 R09: 00007fe7a979e248
> R10: 00007fe7a979e248 R11: 0000000000000246 R12: 00007fe7a979e24c
> R13: 00007ffcfa04d48f R14: 00007fe7a96ba300 R15: 0000000000022000
> </TASK>
>
> Allocated by task 5105:
> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
> kasan_set_track+0x25/0x30 mm/kasan/common.c:52
> ____kasan_kmalloc mm/kasan/common.c:374 [inline]
> ____kasan_kmalloc mm/kasan/common.c:333 [inline]
> __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383
> kmalloc include/linux/slab.h:579 [inline]
> kzalloc include/linux/slab.h:700 [inline]
> vhost_worker_create+0x9c/0x320 drivers/vhost/vhost.c:627
> vhost_dev_set_owner+0x5b9/0xa60 drivers/vhost/vhost.c:885
> vhost_net_set_owner drivers/vhost/net.c:1687 [inline]
> vhost_net_ioctl+0x668/0x16a0 drivers/vhost/net.c:1737
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:870 [inline]
> __se_sys_ioctl fs/ioctl.c:856 [inline]
> __x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:856
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> Freed by task 5108:
> kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
> kasan_set_track+0x25/0x30 mm/kasan/common.c:52
> kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:521
> ____kasan_slab_free mm/kasan/common.c:236 [inline]
> ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
> kasan_slab_free include/linux/kasan.h:164 [inline]
> slab_free_hook mm/slub.c:1792 [inline]
> slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1818
> slab_free mm/slub.c:3801 [inline]
> __kmem_cache_free+0xb8/0x2d0 mm/slub.c:3814
> vhost_worker_destroy drivers/vhost/vhost.c:600 [inline]
> vhost_workers_free drivers/vhost/vhost.c:615 [inline]
> vhost_dev_cleanup+0x66b/0x850 drivers/vhost/vhost.c:991
> vhost_dev_reset_owner+0x25/0x160 drivers/vhost/vhost.c:923
> vhost_net_reset_owner drivers/vhost/net.c:1621 [inline]
> vhost_net_ioctl+0x807/0x16a0 drivers/vhost/net.c:1735
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:870 [inline]
> __se_sys_ioctl fs/ioctl.c:856 [inline]
> __x64_sys_ioctl+0x19d/0x210 fs/ioctl.c:856
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> The buggy address belongs to the object at ffff8880703fff00
> which belongs to the cache kmalloc-cg-192 of size 192
> The buggy address is located 104 bytes inside of
> freed 192-byte region [ffff8880703fff00, ffff8880703fffc0)
>
> The buggy address belongs to the physical page:
> page:ffffea0001c0ffc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x703ff
> flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
> page_type: 0xffffffff()
> raw: 00fff00000000200 ffff88801284ddc0 dead000000000122 0000000000000000
> raw: 0000000000000000 0000000000100010 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 0x16cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY), pid 5034, tgid 5034 (syz-executor204), ts 72916757418, free_ts 72797036103
> set_page_owner include/linux/page_owner.h:31 [inline]
> post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1570
> prep_new_page mm/page_alloc.c:1577 [inline]
> get_page_from_freelist+0xfd9/0x2c40 mm/page_alloc.c:3257
> __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4513
> alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279
> alloc_slab_page mm/slub.c:1862 [inline]
> allocate_slab+0x25f/0x390 mm/slub.c:2009
> new_slab mm/slub.c:2062 [inline]
> ___slab_alloc+0xbc3/0x15d0 mm/slub.c:3215
> __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314
> __slab_alloc_node mm/slub.c:3367 [inline]
> slab_alloc_node mm/slub.c:3460 [inline]
> __kmem_cache_alloc_node+0x143/0x350 mm/slub.c:3509
> __do_kmalloc_node mm/slab_common.c:984 [inline]
> __kmalloc_node+0x51/0x1a0 mm/slab_common.c:992
> kmalloc_node include/linux/slab.h:599 [inline]
> kvmalloc_node+0xa2/0x1a0 mm/util.c:604
> kvmalloc include/linux/slab.h:717 [inline]
> kvzalloc include/linux/slab.h:725 [inline]
> netif_alloc_rx_queues net/core/dev.c:9847 [inline]
> alloc_netdev_mqs+0xbde/0x1270 net/core/dev.c:10660
> ieee80211_if_add+0x1b7/0x19d0 net/mac80211/iface.c:2099
> ieee80211_register_hw+0x37e5/0x40e0 net/mac80211/main.c:1407
> mac80211_hwsim_new_radio+0x26e6/0x4c70 drivers/net/wireless/virtual/mac80211_hwsim.c:5303
> hwsim_new_radio_nl+0xacf/0x1210 drivers/net/wireless/virtual/mac80211_hwsim.c:5983
> genl_family_rcv_msg_doit.isra.0+0x1e6/0x2d0 net/netlink/genetlink.c:970
> page last free stack trace:
> reset_page_owner include/linux/page_owner.h:24 [inline]
> free_pages_prepare mm/page_alloc.c:1161 [inline]
> free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2384
> free_unref_page+0x33/0x370 mm/page_alloc.c:2479
> __unfreeze_partials+0x1fe/0x220 mm/slub.c:2647
> qlink_free mm/kasan/quarantine.c:166 [inline]
> qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185
> kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292
> __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305
> kasan_slab_alloc include/linux/kasan.h:188 [inline]
> slab_post_alloc_hook mm/slab.h:750 [inline]
> slab_alloc_node mm/slub.c:3470 [inline]
> __kmem_cache_alloc_node+0x1ce/0x350 mm/slub.c:3509
> __do_kmalloc_node mm/slab_common.c:984 [inline]
> __kmalloc_node+0x51/0x1a0 mm/slab_common.c:992
> kmalloc_node include/linux/slab.h:599 [inline]
> kvmalloc_node+0xa2/0x1a0 mm/util.c:604
> kvmalloc include/linux/slab.h:717 [inline]
> seq_buf_alloc fs/seq_file.c:38 [inline]
> seq_read_iter+0x7fb/0x12d0 fs/seq_file.c:210
> kernfs_fop_read_iter+0x4ce/0x690 fs/kernfs/file.c:279
> call_read_iter include/linux/fs.h:1865 [inline]
> new_sync_read fs/read_write.c:389 [inline]
> vfs_read+0x4a8/0x8d0 fs/read_write.c:470
> ksys_read+0x122/0x250 fs/read_write.c:613
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> Memory state around the buggy address:
> ffff8880703ffe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8880703ffe80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
> >ffff8880703fff00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff8880703fff80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
> ffff888070400000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> 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 [email protected].
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> 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.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
On 6/26/23 2:15 AM, Michael S. Tsirkin wrote:
> On Mon, Jun 26, 2023 at 12:06:54AM -0700, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 8d2be868b42c Add linux-next specific files for 20230623
>> git tree: linux-next
>> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12872950a80000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=d8ac8dd33677e8e0
>> dashboard link: https://syzkaller.appspot.com/bug?extid=8540db210d403f1aa214
>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1b70f280000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122ee4cb280000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/2a004483aca3/disk-8d2be868.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/5688cb13b277/vmlinux-8d2be868.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/76de0b63bc53/bzImage-8d2be868.xz
>>
>> The issue was bisected to:
>>
>> commit 21a18f4a51896fde11002165f0e7340f4131d6a0
>> Author: Mike Christie <[email protected]>
>> Date: Tue Jun 13 01:32:46 2023 +0000
>>
>> vhost: allow userspace to create workers
>>
>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=130850bf280000
>> final oops: https://syzkaller.appspot.com/x/report.txt?x=108850bf280000
>> console output: https://syzkaller.appspot.com/x/log.txt?x=170850bf280000
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: [email protected]
>> Fixes: 21a18f4a5189 ("vhost: allow userspace to create workers")
>
> Mike, would appreciate prompt attention to this as I am preparing
> a pull request for the merge window and need to make a
> decision on whether to include your userspace-controlled
> threading patchset.
>
Do you want me to resubmit the patchset or submit a patch against your vhost
branch?
The bug is that vhost-net can call vhost_dev_reset_owner and that will
free the workers. However, I leave the virtqueue->worker pointer set so
we end up referencing the freed workers later on. When I handled a
review comment between v5 and v6, I deleted that code thinking it was
also not needed.
So the fix is:
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index ab79b064aade..5a07e220e46d 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -607,6 +607,10 @@ static void vhost_workers_free(struct vhost_dev *dev)
if (!dev->use_worker)
return;
+
+ for (i = 0; i < dev->nvqs; i++)
+ rcu_assign_pointer(dev->vqs[i]->worker, NULL);
+
/*
* Free the default worker we created and cleanup workers userspace
* created but couldn't clean up (it forgot or crashed).
On Mon, Jun 26, 2023 at 10:03:25AM -0500, Mike Christie wrote:
> On 6/26/23 2:15 AM, Michael S. Tsirkin wrote:
> > On Mon, Jun 26, 2023 at 12:06:54AM -0700, syzbot wrote:
> >> Hello,
> >>
> >> syzbot found the following issue on:
> >>
> >> HEAD commit: 8d2be868b42c Add linux-next specific files for 20230623
> >> git tree: linux-next
> >> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12872950a80000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=d8ac8dd33677e8e0
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=8540db210d403f1aa214
> >> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1b70f280000
> >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122ee4cb280000
> >>
> >> Downloadable assets:
> >> disk image: https://storage.googleapis.com/syzbot-assets/2a004483aca3/disk-8d2be868.raw.xz
> >> vmlinux: https://storage.googleapis.com/syzbot-assets/5688cb13b277/vmlinux-8d2be868.xz
> >> kernel image: https://storage.googleapis.com/syzbot-assets/76de0b63bc53/bzImage-8d2be868.xz
> >>
> >> The issue was bisected to:
> >>
> >> commit 21a18f4a51896fde11002165f0e7340f4131d6a0
> >> Author: Mike Christie <[email protected]>
> >> Date: Tue Jun 13 01:32:46 2023 +0000
> >>
> >> vhost: allow userspace to create workers
> >>
> >> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=130850bf280000
> >> final oops: https://syzkaller.appspot.com/x/report.txt?x=108850bf280000
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=170850bf280000
> >>
> >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> >> Reported-by: [email protected]
> >> Fixes: 21a18f4a5189 ("vhost: allow userspace to create workers")
> >
> > Mike, would appreciate prompt attention to this as I am preparing
> > a pull request for the merge window and need to make a
> > decision on whether to include your userspace-controlled
> > threading patchset.
> >
>
> Do you want me to resubmit the patchset or submit a patch against your vhost
> branch?
Resubmit pls.
> The bug is that vhost-net can call vhost_dev_reset_owner and that will
> free the workers. However, I leave the virtqueue->worker pointer set so
> we end up referencing the freed workers later on. When I handled a
> review comment between v5 and v6, I deleted that code thinking it was
> also not needed.
>
> So the fix is:
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index ab79b064aade..5a07e220e46d 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -607,6 +607,10 @@ static void vhost_workers_free(struct vhost_dev *dev)
>
> if (!dev->use_worker)
> return;
> +
> + for (i = 0; i < dev->nvqs; i++)
> + rcu_assign_pointer(dev->vqs[i]->worker, NULL);
> +
> /*
> * Free the default worker we created and cleanup workers userspace
> * created but couldn't clean up (it forgot or crashed).
>
>
On Mon, Jun 26, 2023, Michael S. Tsirkin wrote:
> On Mon, Jun 26, 2023 at 10:03:25AM -0500, Mike Christie wrote:
> > On 6/26/23 2:15 AM, Michael S. Tsirkin wrote:
> > > On Mon, Jun 26, 2023 at 12:06:54AM -0700, syzbot wrote:
> > >> Hello,
> > >>
> > >> syzbot found the following issue on:
> > >>
> > >> HEAD commit: 8d2be868b42c Add linux-next specific files for 20230623
> > >> git tree: linux-next
> > >> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12872950a80000
> > >> kernel config: https://syzkaller.appspot.com/x/.config?x=d8ac8dd33677e8e0
> > >> dashboard link: https://syzkaller.appspot.com/bug?extid=8540db210d403f1aa214
> > >> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> > >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15c1b70f280000
> > >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=122ee4cb280000
> > >>
> > >> Downloadable assets:
> > >> disk image: https://storage.googleapis.com/syzbot-assets/2a004483aca3/disk-8d2be868.raw.xz
> > >> vmlinux: https://storage.googleapis.com/syzbot-assets/5688cb13b277/vmlinux-8d2be868.xz
> > >> kernel image: https://storage.googleapis.com/syzbot-assets/76de0b63bc53/bzImage-8d2be868.xz
> > >>
> > >> The issue was bisected to:
> > >>
> > >> commit 21a18f4a51896fde11002165f0e7340f4131d6a0
> > >> Author: Mike Christie <[email protected]>
> > >> Date: Tue Jun 13 01:32:46 2023 +0000
> > >>
> > >> vhost: allow userspace to create workers
> > >>
> > >> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=130850bf280000
> > >> final oops: https://syzkaller.appspot.com/x/report.txt?x=108850bf280000
> > >> console output: https://syzkaller.appspot.com/x/log.txt?x=170850bf280000
> > >>
> > >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > >> Reported-by: [email protected]
> > >> Fixes: 21a18f4a5189 ("vhost: allow userspace to create workers")
> > >
> > > Mike, would appreciate prompt attention to this as I am preparing
> > > a pull request for the merge window and need to make a
> > > decision on whether to include your userspace-controlled
> > > threading patchset.
> > >
> >
> > Do you want me to resubmit the patchset or submit a patch against your vhost
> > branch?
>
> Resubmit pls.
Closing this out from syzbot's perspective since v9 (now in linux-next and Linus'
tree) added back Mike's fix.
#syz invalid