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AHgh+RqyWxRSvVXxoe7IvGGMuYImS6enIF5djgl9AB5EafSUIDN8SKXwMxm9PMn6K45S5wdcpSvy0minvbNklMY=@vger.kernel.org X-Gm-Message-State: AFuF++kcwRCf3FMDtZIA7AYB2cGhQHXE1JPTIrYgyNMnbERF7pE3KRIl S/wIfQrGmp+JjxmxsppiKFk+EFH+yBya7gbIxEKi9RgadF7rmjPzQoNR68GXzkIw2g82zb2X7in vUi3ptIcujTPTakxo9BJIonzIuIXzI9aMIttZv+mUorlKWTCFZGlE42fShsc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:3090:b0:495:ca1b:7865 with SMTP id 5614622812f47-4b3504b104amr7078694b6e.11.1787688455876; Tue, 25 Aug 2026 13:07:35 -0700 (PDT) Date: Tue, 25 Aug 2026 13:07:35 -0700 In-Reply-To: <20260825152152.86092-1-ahemadkhawar123@gmail.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a8df607.dbb3a75c.7844.002c.GAE@google.com> Subject: [syzbot ci] Re: xsk: Fix circular locking dependency in xsk_bind From: syzbot ci To: ahemadkhawar123@gmail.com, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, kuba@kernel.org, linux-kernel@vger.kernel.org, maciej.fijalkowski@intel.com, magnus.karlsson@intel.com, netdev@vger.kernel.org, pabeni@redhat.com, sdf@fomichev.me, syzbot@syzkaller.appspotmail.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v1] xsk: Fix circular locking dependency in xsk_bind https://lore.kernel.org/all/20260825152152.86092-1-ahemadkhawar123@gmail.com * [PATCH bpf-next] xsk: Fix circular locking dependency in xsk_bind and found the following issue: possible deadlock in xp_clear_dev Full report is available here: https://ci.syzbot.org/series/6f095c15-0f05-4d2e-a9eb-8d4d85f669a6 *** possible deadlock in xp_clear_dev tree: bpf-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next.git base: 5e289c5a4a526e870efac0ca658635c47138593a arch: amd64 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 config: https://ci.syzbot.org/builds/cde9ebbb-b104-4fe4-8779-17786d4f4336/config syz repro: https://ci.syzbot.org/findings/bb56c4f2-d20c-4177-a137-583624105374/syz_repro netlink: 14 bytes leftover after parsing attributes in process `syz.0.17'. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.17/5789 is trying to acquire lock: ffff88816f80ee70 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline] ffff88816f80ee70 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] ffff88816f80ee70 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: xp_clear_dev+0x13b/0x340 net/xdp/xsk_buff_pool.c:297 but task is already holding lock: ffff8881741d06b8 (&xs->mutex){+.+.}-{4:4}, at: xsk_notifier+0xcd/0x230 net/xdp/xsk.c:2109 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&xs->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 xsk_bind+0x2c0/0x1370 net/xdp/xsk.c:1622 __sys_bind_socket net/socket.c:1945 [inline] __sys_bind+0x2e3/0x410 net/socket.c:1976 __do_sys_bind net/socket.c:1981 [inline] __se_sys_bind net/socket.c:1979 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1979 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&dev_instance_lock_key#3){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 netdev_lock include/linux/netdevice.h:2861 [inline] netdev_lock_ops include/net/netdev_lock.h:42 [inline] xp_clear_dev+0x13b/0x340 net/xdp/xsk_buff_pool.c:297 xsk_notifier+0x1a1/0x230 net/xdp/xsk.c:2118 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2313 [inline] call_netdevice_notifiers net/core/dev.c:2327 [inline] unregister_netdevice_many_notify+0x17f9/0x2140 net/core/dev.c:12518 rtnl_delete_link net/core/rtnetlink.c:3652 [inline] rtnl_dellink+0x5be/0x810 net/core/rtnetlink.c:3694 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2713 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767 __sys_sendmsg net/socket.c:2799 [inline] __do_sys_sendmsg net/socket.c:2804 [inline] __se_sys_sendmsg net/socket.c:2802 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xs->mutex); lock(&dev_instance_lock_key#3); lock(&xs->mutex); lock(&dev_instance_lock_key#3); *** DEADLOCK *** locks held by syz.0.17/5789: 3, last CPU#1: #0: ffffffff90036040 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff90036040 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #0: ffffffff90036040 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810 net/core/rtnetlink.c:3686 #1: ffff88801d81eed0 (&net->xdp.lock){+.+.}-{4:4}, at: xsk_notifier+0x89/0x230 net/xdp/xsk.c:2105 #2: ffff8881741d06b8 (&xs->mutex){+.+.}-{4:4}, at: xsk_notifier+0xcd/0x230 net/xdp/xsk.c:2109 stack backtrace: CPU: 1 UID: 0 PID: 5789 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2059 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2191 check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5253 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 netdev_lock include/linux/netdevice.h:2861 [inline] netdev_lock_ops include/net/netdev_lock.h:42 [inline] xp_clear_dev+0x13b/0x340 net/xdp/xsk_buff_pool.c:297 xsk_notifier+0x1a1/0x230 net/xdp/xsk.c:2118 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2313 [inline] call_netdevice_notifiers net/core/dev.c:2327 [inline] unregister_netdevice_many_notify+0x17f9/0x2140 net/core/dev.c:12518 rtnl_delete_link net/core/rtnetlink.c:3652 [inline] rtnl_dellink+0x5be/0x810 net/core/rtnetlink.c:3694 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2713 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767 __sys_sendmsg net/socket.c:2799 [inline] __do_sys_sendmsg net/socket.c:2804 [inline] __se_sys_sendmsg net/socket.c:2802 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2ec039e0d9 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:00007f2ec1214028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2ec0625fa0 RCX: 00007f2ec039e0d9 RDX: 0000000004048004 RSI: 00002000000001c0 RDI: 0000000000000005 RBP: 00007f2ec0435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2ec0626038 R14: 00007f2ec0625fa0 R15: 00007ffca00aa538 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com. To test a fix for this bug, please reply with `#syz test` (on a separate line) and attach the patch to the email. Notes: - The patch will be applied on top of the tested series (as an incremental fix). - To test a new version of the whole series, please send it directly to syzbot@lists.linux.dev. - Arguments like custom git repos and branches are not supported.