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* [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg
@ 2026-02-15 20:21 syzbot
  2026-02-16  0:59 ` Hillf Danton
  2026-02-16  5:16 ` Hillf Danton
  0 siblings, 2 replies; 5+ messages in thread
From: syzbot @ 2026-02-15 20:21 UTC (permalink / raw)
  To: andrii, ast, bpf, daniel, davem, edumazet, horms, jakub,
	john.fastabend, kuba, linux-kernel, netdev, pabeni,
	syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    a040afa3bca4 gve: fix probe failure if clock read fails
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=165bf05a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e3161cabe5a361ff
dashboard link: https://syzkaller.appspot.com/bug?extid=9307c991a6d07ce6e6d8
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13dd245a580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ecdb2a580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ff453661cfef/disk-a040afa3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c65fb54cea84/vmlinux-a040afa3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/94868c75f7e1/bzImage-a040afa3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9307c991a6d07ce6e6d8@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428
Read of size 4 at addr ffff88814cdcf000 by task syz.0.24/6020

CPU: 1 UID: 0 PID: 6020 Comm: syz.0.24 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 sk_msg_recvmsg+0xb54/0xc30 net/core/skmsg.c:428
 udp_bpf_recvmsg+0x4bd/0xe00 net/ipv4/udp_bpf.c:84
 inet_recvmsg+0x260/0x270 net/ipv4/af_inet.c:891
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x1a8/0x270 net/socket.c:1100
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812
 ___sys_recvmsg+0x215/0x590 net/socket.c:2854
 do_recvmmsg+0x334/0x800 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb319f9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb31ad97028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fb31a216090 RCX: 00007fb319f9aeb9
RDX: 0000000000000001 RSI: 0000200000000400 RDI: 0000000000000004
RBP: 00007fb31a008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000040000021 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb31a216128 R14: 00007fb31a216090 R15: 00007ffe21dd0a98
 </TASK>

Allocated by task 6019:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3d1/0x6e0 mm/slub.c:5780
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 alloc_sk_msg net/core/skmsg.c:510 [inline]
 sk_psock_skb_ingress_self+0x60/0x350 net/core/skmsg.c:612
 sk_psock_verdict_apply net/core/skmsg.c:1038 [inline]
 sk_psock_verdict_recv+0x7d9/0x8d0 net/core/skmsg.c:1236
 udp_read_skb+0x73e/0x7e0 net/ipv4/udp.c:2045
 sk_psock_verdict_data_ready+0x12d/0x550 net/core/skmsg.c:1257
 __udp_enqueue_schedule_skb+0xc54/0x10b0 net/ipv4/udp.c:1789
 __udp_queue_rcv_skb net/ipv4/udp.c:2346 [inline]
 udp_queue_rcv_one_skb+0xac5/0x19c0 net/ipv4/udp.c:2475
 __udp4_lib_mcast_deliver+0xc06/0xcf0 net/ipv4/udp.c:2585
 __udp4_lib_rcv+0x10f6/0x2620 net/ipv4/udp.c:2724
 ip_protocol_deliver_rcu+0x282/0x440 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
 dst_input include/net/dst.h:474 [inline]
 ip_sublist_rcv_finish+0x221/0x2a0 net/ipv4/ip_input.c:584
 ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline]
 ip_sublist_rcv+0x5c6/0xa70 net/ipv4/ip_input.c:644
 ip_list_rcv+0x3f1/0x450 net/ipv4/ip_input.c:678
 __netif_receive_skb_list_ptype net/core/dev.c:6195 [inline]
 __netif_receive_skb_list_core+0x7e5/0x810 net/core/dev.c:6242
 __netif_receive_skb_list net/core/dev.c:6294 [inline]
 netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6385
 netif_receive_skb_list+0x54/0x410 net/core/dev.c:6437
 xdp_recv_frames net/bpf/test_run.c:269 [inline]
 xdp_test_run_batch net/bpf/test_run.c:350 [inline]
 bpf_test_run_xdp_live+0x1946/0x1cf0 net/bpf/test_run.c:379
 bpf_prog_test_run_xdp+0x81c/0x1160 net/bpf/test_run.c:1396
 bpf_prog_test_run+0x2c7/0x340 kernel/bpf/syscall.c:4703
 __sys_bpf+0x5cb/0x920 kernel/bpf/syscall.c:6182
 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6272
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6021:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6674 [inline]
 kfree+0x1be/0x650 mm/slub.c:6882
 kfree_sk_msg include/linux/skmsg.h:385 [inline]
 sk_msg_recvmsg+0xaa8/0xc30 net/core/skmsg.c:483
 udp_bpf_recvmsg+0x4bd/0xe00 net/ipv4/udp_bpf.c:84
 inet_recvmsg+0x260/0x270 net/ipv4/af_inet.c:891
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x1a8/0x270 net/socket.c:1100
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2812
 ___sys_recvmsg+0x215/0x590 net/socket.c:2854
 do_recvmmsg+0x334/0x800 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0x198/0x250 net/socket.c:3039
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88814cdcf000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes inside of
 freed 1024-byte region [ffff88814cdcf000, ffff88814cdcf400)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14cdc8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88813fe26dc0 ffffea000509f800 dead000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88813fe26dc0 ffffea000509f800 dead000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000003 ffffea0005337201 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
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 1, tgid 1 (swapper/0), ts 17135672743, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884
 prep_new_page mm/page_alloc.c:1892 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3a0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xd82/0x1760 mm/slub.c:4656
 __slab_alloc+0x65/0x100 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __kmalloc_cache_noprof+0x40d/0x6e0 mm/slub.c:5775
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 init_srcu_struct_fields+0x7f/0xa20 kernel/rcu/srcutree.c:240
 rtnl_link_register+0x141/0x2f0 net/core/rtnetlink.c:615
 ipgre_init+0x64/0x110 net/ipv4/ip_gre.c:1819
 do_one_initcall+0x250/0x840 init/main.c:1378
 do_initcall_level+0x104/0x190 init/main.c:1440
 do_initcalls+0x59/0xa0 init/main.c:1456
 kernel_init_freeable+0x2a6/0x3d0 init/main.c:1688
 kernel_init+0x1d/0x1d0 init/main.c:1578
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88814cdcef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88814cdcef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88814cdcf000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88814cdcf080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88814cdcf100: 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.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.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

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:
#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

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg
  2026-02-15 20:21 [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg syzbot
@ 2026-02-16  0:59 ` Hillf Danton
  2026-02-16  2:10   ` syzbot
  2026-02-16  5:16 ` Hillf Danton
  1 sibling, 1 reply; 5+ messages in thread
From: Hillf Danton @ 2026-02-16  0:59 UTC (permalink / raw)
  To: syzbot; +Cc: linux-kernel, syzkaller-bugs

> Date: Sun, 15 Feb 2026 12:21:29 -0800	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a040afa3bca4 gve: fix probe failure if clock read fails
> git tree:       net
> console output: https://syzkaller.appspot.com/x/log.txt?x=165bf05a580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e3161cabe5a361ff
> dashboard link: https://syzkaller.appspot.com/bug?extid=9307c991a6d07ce6e6d8
> compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13dd245a580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ecdb2a580000

#syz test

--- x/net/core/skmsg.c
+++ y/net/core/skmsg.c
@@ -417,7 +417,9 @@ int sk_msg_recvmsg(struct sock *sk, stru
 	int peek = flags & MSG_PEEK;
 	struct sk_msg *msg_rx;
 	int i, copied = 0;
+	static DEFINE_MUTEX(lk);
 
+	mutex_lock(&lk);
 	msg_rx = sk_psock_peek_msg(psock);
 	while (copied != len) {
 		struct scatterlist *sge;
@@ -485,6 +487,7 @@ int sk_msg_recvmsg(struct sock *sk, stru
 		msg_rx = sk_psock_peek_msg(psock);
 	}
 out:
+	mutex_unlock(&lk);
 	return copied;
 }
 EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
--

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg
  2026-02-16  0:59 ` Hillf Danton
@ 2026-02-16  2:10   ` syzbot
  0 siblings, 0 replies; 5+ messages in thread
From: syzbot @ 2026-02-16  2:10 UTC (permalink / raw)
  To: hdanton, linux-kernel, syzkaller-bugs

Hello,

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

failed to apply patch:
checking file net/core/skmsg.c
Hunk #1 FAILED at 417.
Hunk #2 succeeded at 493 with fuzz 1 (offset 8 lines).
1 out of 2 hunks FAILED



Tested on:

commit:         ee5492fd fbnic: close fw_log race between users and te..
git tree:       net
kernel config:  https://syzkaller.appspot.com/x/.config?x=e3161cabe5a361ff
dashboard link: https://syzkaller.appspot.com/bug?extid=9307c991a6d07ce6e6d8
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12aa015a580000


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg
  2026-02-15 20:21 [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg syzbot
  2026-02-16  0:59 ` Hillf Danton
@ 2026-02-16  5:16 ` Hillf Danton
  2026-02-16  5:36   ` syzbot
  1 sibling, 1 reply; 5+ messages in thread
From: Hillf Danton @ 2026-02-16  5:16 UTC (permalink / raw)
  To: syzbot; +Cc: linux-kernel, syzkaller-bugs

> Date: Sun, 15 Feb 2026 12:21:29 -0800	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a040afa3bca4 gve: fix probe failure if clock read fails
> git tree:       net
> console output: https://syzkaller.appspot.com/x/log.txt?x=165bf05a580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e3161cabe5a361ff
> dashboard link: https://syzkaller.appspot.com/bug?extid=9307c991a6d07ce6e6d8
> compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13dd245a580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ecdb2a580000

#syz test

--- x/net/core/skmsg.c
+++ y/net/core/skmsg.c
@@ -500,7 +500,13 @@ out:
 int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
 		   int len, int flags)
 {
-	return __sk_msg_recvmsg(sk, psock, msg, len, flags, NULL);
+	static DEFINE_MUTEX(lk);
+	int rc;
+
+	mutex_lock(&lk);
+	rc = __sk_msg_recvmsg(sk, psock, msg, len, flags, NULL);
+	mutex_unlock(&lk);
+	return rc;
 }
 EXPORT_SYMBOL_GPL(sk_msg_recvmsg);
 
--

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg
  2026-02-16  5:16 ` Hillf Danton
@ 2026-02-16  5:36   ` syzbot
  0 siblings, 0 replies; 5+ messages in thread
From: syzbot @ 2026-02-16  5:36 UTC (permalink / raw)
  To: hdanton, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in inet_sock_destruct

------------[ cut here ]------------
sk->sk_forward_alloc
WARNING: net/ipv4/af_inet.c:157 at inet_sock_destruct+0x62d/0x740 net/ipv4/af_inet.c:157, CPU#0: swapper/0/0
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:inet_sock_destruct+0x62d/0x740 net/ipv4/af_inet.c:157
Code: 0f 0b 90 e9 58 fe ff ff e8 a0 6b ac f7 90 0f 0b 90 e9 8b fe ff ff e8 92 6b ac f7 90 0f 0b 90 e9 b1 fe ff ff e8 84 6b ac f7 90 <0f> 0b 90 e9 d7 fe ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 95 fc
RSP: 0018:ffffc90000007d48 EFLAGS: 00010246
RAX: ffffffff8a17cf4c RBX: dffffc0000000000 RCX: ffffffff8e494ec0
RDX: 0000000000000100 RSI: 0000000000000f70 RDI: 0000000000000000
RBP: 0000000000000f70 R08: ffff8880353d9c27 R09: 1ffff11006a7b384
R10: dffffc0000000000 R11: ffffed1006a7b385 R12: ffff8880353d9980
R13: dffffc0000000000 R14: ffff8880353d9c0c R15: ffffffff8fc9c980
FS:  0000000000000000(0000) GS:ffff8881254ae000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff98a5e8600 CR3: 000000007804e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __sk_destruct+0x85/0x880 net/core/sock.c:2350
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 24 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 18 2b 00 fb f4 <e9> 7c e8 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000246
RAX: 0000000000128b1b RBX: ffffffff8199661d RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8dee2c77 RDI: ffffffff8c276680
RBP: ffffffff8e407eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb
R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff9010a270
R13: 1ffffffff1c929d8 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/kernel/process.c:766 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:191 [inline]
 do_idle+0x1bd/0x500 kernel/sched/idle.c:332
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430
 rest_init+0x2de/0x300 init/main.c:757
 start_kernel+0x380/0x3d0 init/main.c:1206
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x147
 </TASK>
----------------
Code disassembly (best guess):
   0:	24 7b                	and    $0x7b,%al
   2:	02 c3                	add    %bl,%al
   4:	cc                   	int3
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	cc                   	int3
   a:	cc                   	int3
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d 43 18 2b 00 	verw   0x2b1843(%rip)        # 0x2b186b
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	e9 7c e8 02 00       	jmp    0x2e8ab <-- trapping instruction
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	cc                   	int3
  34:	cc                   	int3
  35:	cc                   	int3
  36:	cc                   	int3
  37:	cc                   	int3
  38:	cc                   	int3
  39:	cc                   	int3
  3a:	cc                   	int3
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop


Tested on:

commit:         ee5492fd fbnic: close fw_log race between users and te..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=10c8affa580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d2b1668f8734e4fc
dashboard link: https://syzkaller.appspot.com/bug?extid=9307c991a6d07ce6e6d8
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12123652580000


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2026-02-16  5:36 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2026-02-15 20:21 [syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_msg_recvmsg syzbot
2026-02-16  0:59 ` Hillf Danton
2026-02-16  2:10   ` syzbot
2026-02-16  5:16 ` Hillf Danton
2026-02-16  5:36   ` syzbot

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