From: syzbot <syzbot+431f9a9e3f5227fbb904@syzkaller.appspotmail.com>
To: kartikey406@gmail.com, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [net?] [bpf?] KASAN: slab-use-after-free Read in __sk_msg_recvmsg
Date: Wed, 01 Apr 2026 22:01:02 -0700 [thread overview]
Message-ID: <69cdf80e.050a0220.182279.0001.GAE@google.com> (raw)
In-Reply-To: <20260402042844.31897-1-kartikey406@gmail.com>
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:162 at inet_sock_destruct+0x62d/0x740 net/ipv4/af_inet.c:162, 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 03/18/2026
RIP: 0010:inet_sock_destruct+0x62d/0x740 net/ipv4/af_inet.c:162
Code: 0f 0b 90 e9 58 fe ff ff e8 50 dd 9e f7 90 0f 0b 90 e9 8b fe ff ff e8 42 dd 9e f7 90 0f 0b 90 e9 b1 fe ff ff e8 34 dd 9e 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: ffffffff8a26d13c RBX: dffffc0000000000 RCX: ffffffff8e494ec0
RDX: 0000000000000100 RSI: 0000000000000090 RDI: 0000000000000000
RBP: 0000000000000090 R08: ffff88801d7bf9a7 R09: 1ffff11003af7f34
R10: dffffc0000000000 R11: ffffed1003af7f35 R12: ffff88801d7bf700
R13: dffffc0000000000 R14: ffff88801d7bf98c R15: ffffffff8fca6c00
FS: 0000000000000000(0000) GS:ffff888125457000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000e54c000 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/0x870 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: 2e 6d 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 e3 42 18 00 fb f4 <e9> fc e9 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: 0000000000104be1 RBX: ffffffff819a913a RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8df2727a RDI: ffffffff8c27ca80
RBP: ffffffff8e407eb0 R08: ffff8880b863399b R09: 1ffff110170c6733
R10: dffffc0000000000 R11: ffffed10170c6734 R12: 0000000000000000
R13: 1ffffffff1c929d8 R14: 0000000000000000 R15: 1ffffffff1c929d8
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:199 [inline]
do_idle+0x36a/0x5f0 kernel/sched/idle.c:352
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451
rest_init+0x2de/0x300 init/main.c:760
start_kernel+0x385/0x3d0 init/main.c:1210
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: 2e 6d cs insl (%dx),%es:(%rdi)
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 e3 42 18 00 verw 0x1842e3(%rip) # 0x18430b
28: fb sti
29: f4 hlt
* 2a: e9 fc e9 02 00 jmp 0x2ea2b <-- 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: cee10a01 net: macb: fix use of at91_default_usrio with..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git main
console output: https://syzkaller.appspot.com/x/log.txt?x=1664d4d2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=71d49d824b43a0d9
dashboard link: https://syzkaller.appspot.com/bug?extid=431f9a9e3f5227fbb904
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=176d65da580000
next parent reply other threads:[~2026-04-02 5:01 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260402042844.31897-1-kartikey406@gmail.com>
2026-04-02 5:01 ` syzbot [this message]
[not found] <20260402021644.30008-1-kartikey406@gmail.com>
2026-04-02 3:39 ` [syzbot] [net?] [bpf?] KASAN: slab-use-after-free Read in __sk_msg_recvmsg syzbot
2026-04-02 0:49 syzbot
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