[syzbot] [net?] KASAN: slab-use-after-free Read in unix_del_edges

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7b4f2bc91c15 Add linux-next specific files for 20240418
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14a54a53180000
kernel config: https://syzkaller.appspot.com/x/.config?x=ae644165a243bf62
dashboard link: https://syzkaller.appspot.com/bug?extid=f3f3eef1d2100200e593
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=155e53af180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128b1d53180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/524a18e6c5be/disk-7b4f2bc9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/029f1b84d653/vmlinux-7b4f2bc9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c02d1542e886/bzImage-7b4f2bc9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f3f3ee...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in unix_edge_successor net/unix/garbage.c:109 [inline]
BUG: KASAN: slab-use-after-free in unix_del_edge net/unix/garbage.c:165 [inline]
BUG: KASAN: slab-use-after-free in unix_del_edges+0x148/0x630 net/unix/garbage.c:237
Read of size 8 at addr ffff888079c6e640 by task kworker/u8:6/1099

CPU: 0 PID: 1099 Comm: kworker/u8:6 Not tainted 6.9.0-rc4-next-20240418-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound __unix_gc
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
unix_edge_successor net/unix/garbage.c:109 [inline]
unix_del_edge net/unix/garbage.c:165 [inline]
unix_del_edges+0x148/0x630 net/unix/garbage.c:237
unix_destroy_fpl+0x59/0x210 net/unix/garbage.c:298
unix_detach_fds net/unix/af_unix.c:1811 [inline]
unix_destruct_scm+0x13e/0x210 net/unix/af_unix.c:1826
skb_release_head_state+0x100/0x250 net/core/skbuff.c:1127
skb_release_all net/core/skbuff.c:1138 [inline]
__kfree_skb net/core/skbuff.c:1154 [inline]
kfree_skb_reason+0x16d/0x3b0 net/core/skbuff.c:1190
__skb_queue_purge_reason include/linux/skbuff.h:3251 [inline]
__skb_queue_purge include/linux/skbuff.h:3256 [inline]
__unix_gc+0x1732/0x1830 net/unix/garbage.c:575
process_one_work kernel/workqueue.c:3218 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
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 14427:
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:312 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3897 [inline]
slab_alloc_node mm/slub.c:3957 [inline]
kmem_cache_alloc_noprof+0x135/0x290 mm/slub.c:3964
sk_prot_alloc+0x58/0x210 net/core/sock.c:2074
sk_alloc+0x38/0x370 net/core/sock.c:2133
unix_create1+0xb4/0x770
unix_create+0x14e/0x200 net/unix/af_unix.c:1034
__sock_create+0x490/0x920 net/socket.c:1571
sock_create net/socket.c:1622 [inline]
__sys_socketpair+0x33e/0x720 net/socket.c:1773
__do_sys_socketpair net/socket.c:1822 [inline]
__se_sys_socketpair net/socket.c:1819 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
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 1805:
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+0xe0/0x150 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:2190 [inline]
slab_free mm/slub.c:4393 [inline]
kmem_cache_free+0x145/0x340 mm/slub.c:4468
sk_prot_free net/core/sock.c:2114 [inline]
__sk_destruct+0x467/0x5f0 net/core/sock.c:2208
sock_put include/net/sock.h:1948 [inline]
unix_release_sock+0xa8b/0xd20 net/unix/af_unix.c:665
unix_release+0x91/0xc0 net/unix/af_unix.c:1049
__sock_release net/socket.c:659 [inline]
sock_close+0xbc/0x240 net/socket.c:1421
__fput+0x406/0x8b0 fs/file_table.c:422
delayed_fput+0x59/0x80 fs/file_table.c:445
process_one_work kernel/workqueue.c:3218 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
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

The buggy address belongs to the object at ffff888079c6e000
which belongs to the cache UNIX of size 1920
The buggy address is located 1600 bytes inside of
freed 1920-byte region [ffff888079c6e000, ffff888079c6e780)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888079c6c000 pfn:0x79c68
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000240(workingset|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffefff(slab)
raw: 00fff80000000240 ffff888017395a00 ffff8880173357c8 ffffea0001f97410
raw: ffff888079c6c000 0000000000100005 00000001ffffefff 0000000000000000
head: 00fff80000000240 ffff888017395a00 ffff8880173357c8 ffffea0001f97410
head: ffff888079c6c000 0000000000100005 00000001ffffefff 0000000000000000
head: 00fff80000000003 ffffea0001e71a01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7008, tgid -583571348 (syz-executor297), ts 7008, free_ts 67977031729
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1476
prep_new_page mm/page_alloc.c:1484 [inline]
get_page_from_freelist+0x2ce2/0x2d90 mm/page_alloc.c:3446
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4704
__alloc_pages_node_noprof include/linux/gfp.h:244 [inline]
alloc_pages_node_noprof include/linux/gfp.h:271 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2259
allocate_slab+0x5a/0x2e0 mm/slub.c:2422
new_slab mm/slub.c:2475 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3624
__slab_alloc+0x58/0xa0 mm/slub.c:3714
__slab_alloc_node mm/slub.c:3767 [inline]
slab_alloc_node mm/slub.c:3945 [inline]
kmem_cache_alloc_noprof+0x1c1/0x290 mm/slub.c:3964
sk_prot_alloc+0x58/0x210 net/core/sock.c:2074
sk_alloc+0x38/0x370 net/core/sock.c:2133
unix_create1+0xb4/0x770
unix_create+0x14e/0x200 net/unix/af_unix.c:1034
__sock_create+0x490/0x920 net/socket.c:1571
sock_create net/socket.c:1622 [inline]
__sys_socketpair+0x33e/0x720 net/socket.c:1773
__do_sys_socketpair net/socket.c:1822 [inline]
__se_sys_socketpair net/socket.c:1819 [inline]
__x64_sys_socketpair+0x9b/0xb0 net/socket.c:1819
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
page last free pid 5089 tgid 5089 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1096 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2609
__slab_free+0x31b/0x3d0 mm/slub.c:4304
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9e/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:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3897 [inline]
slab_alloc_node mm/slub.c:3957 [inline]
kmem_cache_alloc_noprof+0x135/0x290 mm/slub.c:3964
vma_lock_alloc kernel/fork.c:441 [inline]
vm_area_dup+0x61/0x290 kernel/fork.c:494
dup_mmap kernel/fork.c:697 [inline]
dup_mm kernel/fork.c:1688 [inline]
copy_mm+0xcf5/0x1fb0 kernel/fork.c:1737
copy_process+0x187a/0x3dc0 kernel/fork.c:2390
kernel_clone+0x226/0x8f0 kernel/fork.c:2797
__do_sys_clone kernel/fork.c:2940 [inline]
__se_sys_clone kernel/fork.c:2924 [inline]
__x64_sys_clone+0x258/0x2a0 kernel/fork.c:2924
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

Memory state around the buggy address:
ffff888079c6e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888079c6e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888079c6e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888079c6e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888079c6e700: fb 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 syzk...@googlegroups.com.

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If the report is already addressed, let syzbot know by replying with:
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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 overwrite report's subsystems, reply with:
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If you want to undo deduplication, reply with:
#syz undup

[Hillf Danton]

On Fri, 19 Apr 2024 02:39:21 -0700

> syzbot found the following issue on:
>
> HEAD commit: 7b4f2bc91c15 Add linux-next specific files for 20240418
> git tree: linux-next

> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128b1d53180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 7b4f2bc91c15

--- x/net/unix/garbage.c
+++ y/net/unix/garbage.c
@@ -205,6 +205,7 @@ void unix_add_edges(struct scm_fp_list *
edge = fpl->edges + i++;
edge->predecessor = inflight;
edge->successor = receiver;
+ sock_hold((struct sock *)receiver);

unix_add_edge(fpl, edge);
} while (i < fpl->count_unix);
@@ -225,6 +226,7 @@ void unix_del_edges(struct scm_fp_list *
{
struct unix_sock *receiver;
int i = 0;
+ int j;

spin_lock(&unix_gc_lock);

@@ -246,6 +248,12 @@ out:
spin_unlock(&unix_gc_lock);

fpl->inflight = false;
+
+ for (j = 0; j < i; j++) {
+ struct unix_edge *edge = fpl->edges + j;
+
+ sock_put((struct sock *)(edge->successor));
+ }
}

void unix_update_edges(struct unix_sock *receiver)
--

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+f3f3ee...@syzkaller.appspotmail.com

Tested on:

commit: 7b4f2bc9 Add linux-next specific files for 20240418
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=11e892bf180000

kernel config: https://syzkaller.appspot.com/x/.config?x=ae644165a243bf62
dashboard link: https://syzkaller.appspot.com/bug?extid=f3f3eef1d2100200e593
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=15ad594f180000

Note: testing is done by a robot and is best-effort only.

[Kuniyuki Iwashima]

From: syzbot <syzbot+f3f3ee...@syzkaller.appspotmail.com>
Date: Fri, 19 Apr 2024 02:39:21 -0700

It seems successor is freed during the same GC iteration ?

Will cook a patch soon.

Thanks!

[Kuniyuki Iwashima]

From: syzbot <syzbot+f3f3ee...@syzkaller.appspotmail.com>
Date: Fri, 19 Apr 2024 02:39:21 -0700

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 7b4f2bc91c15 Add linux-next specific files for 20240418
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=14a54a53180000
> kernel config: https://syzkaller.appspot.com/x/.config?x=ae644165a243bf62
> dashboard link: https://syzkaller.appspot.com/bug?extid=f3f3eef1d2100200e593
> 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=155e53af180000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128b1d53180000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/524a18e6c5be/disk-7b4f2bc9.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/029f1b84d653/vmlinux-7b4f2bc9.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/c02d1542e886/bzImage-7b4f2bc9.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+f3f3ee...@syzkaller.appspotmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git main

diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index 95240a59808f..039c1c8c73f4 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -158,11 +158,14 @@ static void unix_add_edge(struct scm_fp_list *fpl, struct unix_edge *edge)
unix_update_graph(unix_edge_successor(edge));
}

+static bool gc_in_progress;
+
static void unix_del_edge(struct scm_fp_list *fpl, struct unix_edge *edge)
{
struct unix_vertex *vertex = edge->predecessor->vertex;

- unix_update_graph(unix_edge_successor(edge));
+ if (!gc_in_progress)
+ unix_update_graph(unix_edge_successor(edge));

list_del(&edge->vertex_entry);
vertex->out_degree--;
@@ -237,8 +240,10 @@ void unix_del_edges(struct scm_fp_list *fpl)
unix_del_edge(fpl, edge);
} while (i < fpl->count_unix);

- receiver = fpl->edges[0].successor;
- receiver->scm_stat.nr_unix_fds -= fpl->count_unix;
+ if (!gc_in_progress) {
+ receiver = fpl->edges[0].successor;
+ receiver->scm_stat.nr_unix_fds -= fpl->count_unix;
+ }
WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - fpl->count_unix);
out:
WRITE_ONCE(fpl->user->unix_inflight, fpl->user->unix_inflight - fpl->count);
@@ -550,8 +555,6 @@ static void unix_walk_scc_fast(struct sk_buff_head *hitlist)
list_replace_init(&unix_visited_vertices, &unix_unvisited_vertices);
}

-static bool gc_in_progress;
-
static void __unix_gc(struct work_struct *work)
{
struct sk_buff_head hitlist;

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

registered new interface driver rtsx_usb
[ 7.654500][ T1] usbcore: registered new interface driver viperboard
[ 7.656820][ T1] usbcore: registered new interface driver dln2
[ 7.658229][ T1] usbcore: registered new interface driver pn533_usb
[ 7.665094][ T1] nfcsim 0.2 initialized
[ 7.666287][ T1] usbcore: registered new interface driver port100
[ 7.667860][ T1] usbcore: registered new interface driver nfcmrvl
[ 7.677894][ T1] Loading iSCSI transport class v2.0-870.
[ 7.691826][ T1] virtio_scsi virtio0: 1/0/0 default/read/poll queues
[ 7.700510][ T1] ------------[ cut here ]------------
[ 7.701647][ T1] refcount_t: decrement hit 0; leaking memory.
[ 7.702712][ T1] WARNING: CPU: 1 PID: 1 at lib/refcount.c:31 refcount_warn_saturate+0xfa/0x1d0
[ 7.705030][ T1] Modules linked in:
[ 7.705931][ T1] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc4-syzkaller-00895-g4cad4efa6eb2-dirty #0
[ 7.707420][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 7.708867][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 7.709787][ T1] Code: b2 00 00 00 e8 97 ee e6 fc 5b 5d c3 cc cc cc cc e8 8b ee e6 fc c6 05 92 84 e4 0a 01 90 48 c7 c7 80 33 1f 8c e8 f7 6a a9 fc 90 <0f> 0b 90 90 eb d9 e8 6b ee e6 fc c6 05 6f 84 e4 0a 01 90 48 c7 c7
[ 7.712924][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 7.714098][ T1] RAX: 802fad55264ab500 RBX: ffff888146ad6b3c RCX: ffff8880166d0000
[ 7.715583][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 7.717186][ T1] RBP: 0000000000000004 R08: ffffffff81588082 R09: fffffbfff1c39b48
[ 7.718689][ T1] R10: dffffc0000000000 R11: fffffbfff1c39b48 R12: ffffea0000850dc0
[ 7.720446][ T1] R13: ffffea0000850dc8 R14: 1ffffd400010a1b9 R15: 0000000000000000
[ 7.721919][ T1] FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
[ 7.723283][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 7.724203][ T1] CR2: 0000000000000000 CR3: 000000000e134000 CR4: 00000000003506f0
[ 7.725329][ T1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 7.726405][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 7.727490][ T1] Call Trace:
[ 7.727952][ T1] <TASK>
[ 7.728408][ T1] ? __warn+0x163/0x4e0
[ 7.729132][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.729918][ T1] ? report_bug+0x2b3/0x500
[ 7.730722][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.731598][ T1] ? handle_bug+0x3e/0x70
[ 7.732470][ T1] ? exc_invalid_op+0x1a/0x50
[ 7.733180][ T1] ? asm_exc_invalid_op+0x1a/0x20
[ 7.734321][ T1] ? __warn_printk+0x292/0x360
[ 7.735110][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.736046][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 7.737157][ T1] __free_pages_ok+0xc60/0xd90
[ 7.737974][ T1] make_alloc_exact+0xa3/0xf0
[ 7.739152][ T1] vring_alloc_queue_split+0x20a/0x600
[ 7.739921][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 7.740857][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 7.742030][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 7.743130][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 7.744156][ T1] ? really_probe+0x2b8/0xad0
[ 7.745411][ T1] ? driver_probe_device+0x50/0x430
[ 7.746481][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 7.747395][ T1] ? ret_from_fork+0x4b/0x80
[ 7.748185][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 7.749718][ T1] vring_create_virtqueue+0xca/0x110
[ 7.750680][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.751352][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.752127][ T1] setup_vq+0xe9/0x2d0
[ 7.752740][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.753739][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.754582][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.755808][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.756624][ T1] vp_setup_vq+0xbf/0x330
[ 7.757294][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 7.758740][ T1] ? ioread16+0x2f/0x90
[ 7.759423][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.760184][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 7.761570][ T1] vp_find_vqs+0x4c/0x4e0
[ 7.762347][ T1] virtscsi_init+0x8db/0xd00
[ 7.763210][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 7.764163][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 7.765029][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 7.765845][ T1] ? vp_get+0xfd/0x140
[ 7.766595][ T1] virtscsi_probe+0x3ea/0xf60
[ 7.767420][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 7.768268][ T1] ? kernfs_add_one+0x156/0x8b0
[ 7.769025][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 7.769838][ T1] ? virtio_features_ok+0x10c/0x270
[ 7.770612][ T1] virtio_dev_probe+0x991/0xaf0
[ 7.771348][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 7.772249][ T1] really_probe+0x2b8/0xad0
[ 7.773081][ T1] __driver_probe_device+0x1a2/0x390
[ 7.774142][ T1] driver_probe_device+0x50/0x430
[ 7.775055][ T1] __driver_attach+0x45f/0x710
[ 7.775738][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.777068][ T1] bus_for_each_dev+0x239/0x2b0
[ 7.778013][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.778935][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 7.779835][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 7.780678][ T1] bus_add_driver+0x347/0x620
[ 7.781572][ T1] driver_register+0x23a/0x320
[ 7.782416][ T1] virtio_scsi_init+0x69/0xe0
[ 7.783114][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.783862][ T1] do_one_initcall+0x248/0x880
[ 7.784838][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.785602][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.786590][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.787715][ T1] ? __pfx_parse_args+0x10/0x10
[ 7.788740][ T1] ? do_initcalls+0x1c/0x80
[ 7.789436][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.790134][ T1] do_initcall_level+0x157/0x210
[ 7.791134][ T1] do_initcalls+0x3f/0x80
[ 7.791963][ T1] kernel_init_freeable+0x435/0x5d0
[ 7.792838][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 7.793797][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.794852][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.795572][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.796447][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.797205][ T1] kernel_init+0x1d/0x2b0
[ 7.797981][ T1] ret_from_fork+0x4b/0x80
[ 7.798980][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.799980][ T1] ret_from_fork_asm+0x1a/0x30
[ 7.801171][ T1] </TASK>
[ 7.801810][ T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[ 7.802882][ T1] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.9.0-rc4-syzkaller-00895-g4cad4efa6eb2-dirty #0
[ 7.804509][ T1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
[ 7.804834][ T1] Call Trace:
[ 7.804834][ T1] <TASK>
[ 7.804834][ T1] dump_stack_lvl+0x241/0x360
[ 7.804834][ T1] ? __pfx_dump_stack_lvl+0x10/0x10
[ 7.804834][ T1] ? __pfx__printk+0x10/0x10
[ 7.804834][ T1] ? _printk+0xd5/0x120
[ 7.804834][ T1] ? vscnprintf+0x5d/0x90
[ 7.804834][ T1] panic+0x349/0x860
[ 7.804834][ T1] ? __warn+0x172/0x4e0
[ 7.804834][ T1] ? __pfx_panic+0x10/0x10
[ 7.804834][ T1] ? show_trace_log_lvl+0x4e6/0x520
[ 7.814431][ T1] ? ret_from_fork_asm+0x1a/0x30
[ 7.814431][ T1] __warn+0x346/0x4e0
[ 7.814431][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.814431][ T1] report_bug+0x2b3/0x500
[ 7.814431][ T1] ? refcount_warn_saturate+0xfa/0x1d0
[ 7.814431][ T1] handle_bug+0x3e/0x70
[ 7.814431][ T1] exc_invalid_op+0x1a/0x50
[ 7.814431][ T1] asm_exc_invalid_op+0x1a/0x20
[ 7.814431][ T1] RIP: 0010:refcount_warn_saturate+0xfa/0x1d0
[ 7.814431][ T1] Code: b2 00 00 00 e8 97 ee e6 fc 5b 5d c3 cc cc cc cc e8 8b ee e6 fc c6 05 92 84 e4 0a 01 90 48 c7 c7 80 33 1f 8c e8 f7 6a a9 fc 90 <0f> 0b 90 90 eb d9 e8 6b ee e6 fc c6 05 6f 84 e4 0a 01 90 48 c7 c7
[ 7.814431][ T1] RSP: 0000:ffffc90000066e18 EFLAGS: 00010246
[ 7.824572][ T1] RAX: 802fad55264ab500 RBX: ffff888146ad6b3c RCX: ffff8880166d0000
[ 7.824572][ T1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 7.824572][ T1] RBP: 0000000000000004 R08: ffffffff81588082 R09: fffffbfff1c39b48
[ 7.824572][ T1] R10: dffffc0000000000 R11: fffffbfff1c39b48 R12: ffffea0000850dc0
[ 7.824572][ T1] R13: ffffea0000850dc8 R14: 1ffffd400010a1b9 R15: 0000000000000000
[ 7.824572][ T1] ? __warn_printk+0x292/0x360
[ 7.824572][ T1] ? refcount_warn_saturate+0xf9/0x1d0
[ 7.824572][ T1] __free_pages_ok+0xc60/0xd90
[ 7.824572][ T1] make_alloc_exact+0xa3/0xf0
[ 7.824572][ T1] vring_alloc_queue_split+0x20a/0x600
[ 7.824572][ T1] ? __pfx_vring_alloc_queue_split+0x10/0x10
[ 7.834413][ T1] ? vp_find_vqs+0x4c/0x4e0
[ 7.834413][ T1] ? virtscsi_probe+0x3ea/0xf60
[ 7.834413][ T1] ? virtio_dev_probe+0x991/0xaf0
[ 7.834413][ T1] ? really_probe+0x2b8/0xad0
[ 7.834413][ T1] ? driver_probe_device+0x50/0x430
[ 7.834413][ T1] vring_create_virtqueue_split+0xc6/0x310
[ 7.834413][ T1] ? ret_from_fork+0x4b/0x80
[ 7.834413][ T1] ? __pfx_vring_create_virtqueue_split+0x10/0x10
[ 7.834413][ T1] vring_create_virtqueue+0xca/0x110
[ 7.834413][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.834413][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.834413][ T1] setup_vq+0xe9/0x2d0
[ 7.834413][ T1] ? __pfx_vp_notify+0x10/0x10
[ 7.844326][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.844326][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.844326][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.844326][ T1] vp_setup_vq+0xbf/0x330
[ 7.844326][ T1] ? __pfx_vp_config_changed+0x10/0x10
[ 7.844326][ T1] ? ioread16+0x2f/0x90
[ 7.844326][ T1] ? __pfx_virtscsi_ctrl_done+0x10/0x10
[ 7.844326][ T1] vp_find_vqs_msix+0x8b2/0xc80
[ 7.844326][ T1] vp_find_vqs+0x4c/0x4e0
[ 7.844326][ T1] virtscsi_init+0x8db/0xd00
[ 7.844326][ T1] ? __pfx_virtscsi_init+0x10/0x10
[ 7.844326][ T1] ? __pfx_default_calc_sets+0x10/0x10
[ 7.844326][ T1] ? scsi_host_alloc+0xa57/0xea0
[ 7.844326][ T1] ? vp_get+0xfd/0x140
[ 7.854405][ T1] virtscsi_probe+0x3ea/0xf60
[ 7.854405][ T1] ? __pfx_virtscsi_probe+0x10/0x10
[ 7.854405][ T1] ? kernfs_add_one+0x156/0x8b0
[ 7.854405][ T1] ? virtio_no_restricted_mem_acc+0x9/0x10
[ 7.854405][ T1] ? virtio_features_ok+0x10c/0x270
[ 7.854405][ T1] virtio_dev_probe+0x991/0xaf0
[ 7.854405][ T1] ? __pfx_virtio_dev_probe+0x10/0x10
[ 7.854405][ T1] really_probe+0x2b8/0xad0
[ 7.854405][ T1] __driver_probe_device+0x1a2/0x390
[ 7.854405][ T1] driver_probe_device+0x50/0x430
[ 7.854405][ T1] __driver_attach+0x45f/0x710
[ 7.854405][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.854405][ T1] bus_for_each_dev+0x239/0x2b0
[ 7.864323][ T1] ? __pfx___driver_attach+0x10/0x10
[ 7.864323][ T1] ? __pfx_bus_for_each_dev+0x10/0x10
[ 7.864323][ T1] ? do_raw_spin_unlock+0x13c/0x8b0
[ 7.864323][ T1] bus_add_driver+0x347/0x620
[ 7.864323][ T1] driver_register+0x23a/0x320
[ 7.864323][ T1] virtio_scsi_init+0x69/0xe0
[ 7.864323][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.864323][ T1] do_one_initcall+0x248/0x880
[ 7.864323][ T1] ? __pfx_virtio_scsi_init+0x10/0x10
[ 7.864323][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.864323][ T1] ? __pfx_do_one_initcall+0x10/0x10
[ 7.864323][ T1] ? __pfx_parse_args+0x10/0x10
[ 7.864323][ T1] ? do_initcalls+0x1c/0x80
[ 7.864323][ T1] ? rcu_is_watching+0x15/0xb0
[ 7.874391][ T1] do_initcall_level+0x157/0x210
[ 7.874391][ T1] do_initcalls+0x3f/0x80
[ 7.874391][ T1] kernel_init_freeable+0x435/0x5d0
[ 7.874391][ T1] ? __pfx_kernel_init_freeable+0x10/0x10
[ 7.874391][ T1] ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
[ 7.874391][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.874391][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.874391][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.874391][ T1] kernel_init+0x1d/0x2b0
[ 7.874391][ T1] ret_from_fork+0x4b/0x80
[ 7.874391][ T1] ? __pfx_kernel_init+0x10/0x10
[ 7.874391][ T1] ret_from_fork_asm+0x1a/0x30
[ 7.874391][ T1] </TASK>
[ 7.884330][ T1] Kernel Offset: disabled
[ 7.884330][ T1] Rebooting in 86400 seconds..


syzkaller build log:
go env (err=<nil>)
GO111MODULE='auto'
GOARCH='amd64'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.21.4'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3954342966=/tmp/go-build -gno-record-gcc-switches'

git status (err=<nil>)
HEAD detached at af24b0505
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' ./sys/syz-sysgen | grep -q false || go install ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=af24b0505c748561efb50f1d03c824d6642f6c0b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240418-062732'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-fuzzer github.com/google/syzkaller/syz-fuzzer
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=af24b0505c748561efb50f1d03c824d6642f6c0b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240418-062732'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
GOOS=linux GOARCH=amd64 go build "-ldflags=-s -w -X github.com/google/syzkaller/prog.GitRevision=af24b0505c748561efb50f1d03c824d6642f6c0b -X 'github.com/google/syzkaller/prog.gitRevisionDate=20240418-062732'" "-tags=syz_target syz_os_linux syz_arch_amd64 " -o ./bin/linux_amd64/syz-stress github.com/google/syzkaller/tools/syz-stress
mkdir -p ./bin/linux_amd64
gcc -o ./bin/linux_amd64/syz-executor executor/executor.cc \
-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -fpermissive -w -DGOOS_linux=1 -DGOARCH_amd64=1 \
-DHOSTGOOS_linux=1 -DGIT_REVISION=\"af24b0505c748561efb50f1d03c824d6642f6c0b\"


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=11617880980000


Tested on:

commit: 4cad4efa Merge branch 'net-neigh-rcu'
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git main
kernel config: https://syzkaller.appspot.com/x/.config?x=ecd971c4c871c35d

dashboard link: https://syzkaller.appspot.com/bug?extid=f3f3eef1d2100200e593
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=15ef206f180000

[syzbot]

syzbot has bisected this issue to:

commit 77e5593aebba823bcbcf2c4b58b07efcd63933b8
Author: Kuniyuki Iwashima <kun...@amazon.com>
Date: Mon Mar 25 20:24:20 2024 +0000

af_unix: Skip GC if no cycle exists.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14bbda4f180000
start commit: 7b4f2bc91c15 Add linux-next specific files for 20240418
git tree: linux-next
final oops: https://syzkaller.appspot.com/x/report.txt?x=16bbda4f180000
console output: https://syzkaller.appspot.com/x/log.txt?x=12bbda4f180000

kernel config: https://syzkaller.appspot.com/x/.config?x=ae644165a243bf62
dashboard link: https://syzkaller.appspot.com/bug?extid=f3f3eef1d2100200e593

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=155e53af180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128b1d53180000

Reported-by: syzbot+f3f3ee...@syzkaller.appspotmail.com
Fixes: 77e5593aebba ("af_unix: Skip GC if no cycle exists.")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection