From patchwork Sun Mar 3 14:48:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13579802 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9138B2E412 for ; Sun, 3 Mar 2024 14:48:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709477285; cv=none; b=iQNyo4yo8vAAeoNf2zutHBNKHvnIj7ulmAZB1voeJfV8tGcNHp7EWzsxjjk//WA7U0xbK3QN5asoxwMEtBEslarF0kKokosNs40uO51B9Q7yhy/MZknZB8f52larw6X/CaLaaX5i9H9ryBYJAg3D8PQVyYPq+rMnicd/RAKKN+k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709477285; c=relaxed/simple; bh=r5yvuHj/iCNRM0LxTbTQj8SE0mKMPlfwsmh18e7xolI=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=mG/7TbR5URvci0irGnlKaDfvkty8u6Z+qMl4A7VICPd/ua0Tlgm6xSf5YHWF3IRY0ZF/JBNh2eYoofNiBVrGf6FX9yj93cEU5KR2xbM05brJyJAnoOilEXCI/NShD8+usO57xCIH2yOzQv4UZb/GLcKDzFsIqWENIQvOVOWptk0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=kOFWlfrY; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kOFWlfrY" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-60998ed9df5so13288657b3.3 for ; Sun, 03 Mar 2024 06:48:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709477282; x=1710082082; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=LWpl37k+vNxC8MKMsn7FXXdvFXYFZL/S6M1c6cwpzBA=; b=kOFWlfrYSW0N1y28VJsDxexqCYOQC85VHXMok2vWUP/47yhpSm2aIy1zV07JR4X7kO WnkyVkKZvicABBF2T4RFfjQX3jC4rx1Z1gN/4Tdn8mgnGxO4VqQXxdA3CkWr96CMxDcT 7FmXHPB0cjssVNI9axCQoKGy5+IzvMbfyiJULj2jk/GWBw9HkwGdj14Ggux6j9rBXiRA eqn+SRFVzWAOSbAtJ9gHauo85/84SJz/cM71lfUmFycyOmjrVSg56CBxg59oZMcgmOYt 3fL3uKKcu/d7udBGl4373v7BMqoA3jHg6ZjQLh5EWV/+hBVzMHb/F8HXfba4likA2/0z mzfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709477282; x=1710082082; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=LWpl37k+vNxC8MKMsn7FXXdvFXYFZL/S6M1c6cwpzBA=; b=In37/k1yV51Od7V8sRl8by2Qe96UgyuMIMfurpfNsbL6pqjAq4J+czM/rXdAcPvgGD HkYgb9oxcNq9dole8mUk07YFrSbE6w0jdQ+Jjm3za+Wd7SyJ9z4iYXSJPHXNPRg9o9W9 cO8kU56qGbskVGtAkwVGnBSb8xbSxwZN5LBapWhNUtxSHUimHvrL9NZX+/dzYrWq4qlo 0qJUx6XrDCYPPGkM0UvjpD1clVddVT9SRokaBR2SMpMrpQ5LcvjVS+kUVmBthuW8xIQQ t8RRXGaRh1yATYdWvvFCkhtDgGmnMVI9+lzHGNSpk4gOE0CuBpi2Pe1heL5WX6+cv17Z kBVQ== X-Gm-Message-State: AOJu0YyOQDXETyZ1HlMTWzK5W4tttx3FZpI6QKqep4FFI7VjLebfZ58p yvuLl33EWGaXb7pWN7JeU9JD0TQkMY43bI+4H/z8FfjxmdJub3XjwzUkIgb99kTVkkXyrc97Cy1 /tqI/DLTxeA== X-Google-Smtp-Source: AGHT+IEHxn+TjrV3npZ5qEJgesXoBS99f416emBZdp8tOSCZz/JtAY3q9lIerA2z/Y8uD5gc5IO4iNZ4IhF7hg== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a81:7947:0:b0:609:359a:9313 with SMTP id u68-20020a817947000000b00609359a9313mr1480013ywc.1.1709477282606; Sun, 03 Mar 2024 06:48:02 -0800 (PST) Date: Sun, 3 Mar 2024 14:48:00 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.44.0.278.ge034bb2e1d-goog Message-ID: <20240303144801.702646-1-edumazet@google.com> Subject: [PATCH net] net/ipv6: avoid possible UAF in ip6_route_mpath_notify() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , syzbot , David Ahern X-Patchwork-Delegate: kuba@kernel.org syzbot found another use-after-free in ip6_route_mpath_notify() [1] Commit f7225172f25a ("net/ipv6: prevent use after free in ip6_route_mpath_notify") was not able to fix the root cause. We need to defer the fib6_info_release() calls after ip6_route_mpath_notify(), in the cleanup phase. [1] BUG: KASAN: slab-use-after-free in rt6_fill_node+0x1460/0x1ac0 Read of size 4 at addr ffff88809a07fc64 by task syz-executor.2/23037 CPU: 0 PID: 23037 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-01035-gea7f3cfaa588 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x167/0x540 mm/kasan/report.c:488 kasan_report+0x142/0x180 mm/kasan/report.c:601 rt6_fill_node+0x1460/0x1ac0 inet6_rt_notify+0x13b/0x290 net/ipv6/route.c:6184 ip6_route_mpath_notify net/ipv6/route.c:5198 [inline] ip6_route_multipath_add net/ipv6/route.c:5404 [inline] inet6_rtm_newroute+0x1d0f/0x2300 net/ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f73dd87dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f73de6550c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f73dd9ac050 RCX: 00007f73dd87dda9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 00007f73dd8ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f73dd9ac050 R15: 00007ffdbdeb7858 Allocated by task 23037: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:372 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3981 [inline] __kmalloc+0x22e/0x490 mm/slub.c:3994 kmalloc include/linux/slab.h:594 [inline] kzalloc include/linux/slab.h:711 [inline] fib6_info_alloc+0x2e/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x445/0x12b0 net/ipv6/route.c:3758 ip6_route_multipath_add net/ipv6/route.c:5298 [inline] inet6_rtm_newroute+0x744/0x2300 net/ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 Freed by task 16: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640 poison_slab_object+0xa6/0xe0 mm/kasan/common.c:241 __kasan_slab_free+0x34/0x70 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x14a/0x380 mm/slub.c:4409 rcu_do_batch kernel/rcu/tree.c:2190 [inline] rcu_core+0xd76/0x1810 kernel/rcu/tree.c:2465 __do_softirq+0x2bb/0x942 kernel/softirq.c:553 Last potentially related work creation: kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47 __kasan_record_aux_stack+0xae/0x100 mm/kasan/generic.c:586 __call_rcu_common kernel/rcu/tree.c:2715 [inline] call_rcu+0x167/0xa80 kernel/rcu/tree.c:2829 fib6_info_release include/net/ip6_fib.h:341 [inline] ip6_route_multipath_add net/ipv6/route.c:5344 [inline] inet6_rtm_newroute+0x114d/0x2300 net/ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 The buggy address belongs to the object at ffff88809a07fc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 100 bytes inside of freed 512-byte region [ffff88809a07fc00, ffff88809a07fe00) The buggy address belongs to the physical page: page:ffffea0002681f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x9a07c head:ffffea0002681f00 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888014c41c80 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 23028, tgid 23027 (syz-executor.4), ts 2340253595219, free_ts 2339107097036 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311 __alloc_pages+0x255/0x680 mm/page_alloc.c:4567 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] alloc_slab_page+0x5f/0x160 mm/slub.c:2190 allocate_slab mm/slub.c:2354 [inline] new_slab+0x84/0x2f0 mm/slub.c:2407 ___slab_alloc+0xd17/0x13e0 mm/slub.c:3540 __slab_alloc mm/slub.c:3625 [inline] __slab_alloc_node mm/slub.c:3678 [inline] slab_alloc_node mm/slub.c:3850 [inline] __do_kmalloc_node mm/slub.c:3980 [inline] __kmalloc+0x2e0/0x490 mm/slub.c:3994 kmalloc include/linux/slab.h:594 [inline] kzalloc include/linux/slab.h:711 [inline] new_dir fs/proc/proc_sysctl.c:956 [inline] get_subdir fs/proc/proc_sysctl.c:1000 [inline] sysctl_mkdir_p fs/proc/proc_sysctl.c:1295 [inline] __register_sysctl_table+0xb30/0x1440 fs/proc/proc_sysctl.c:1376 neigh_sysctl_register+0x416/0x500 net/core/neighbour.c:3859 devinet_sysctl_register+0xaf/0x1f0 net/ipv4/devinet.c:2644 inetdev_init+0x296/0x4d0 net/ipv4/devinet.c:286 inetdev_event+0x338/0x15c0 net/ipv4/devinet.c:1555 notifier_call_chain+0x18f/0x3b0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:1987 [inline] call_netdevice_notifiers net/core/dev.c:2001 [inline] register_netdevice+0x15b2/0x1a20 net/core/dev.c:10340 br_dev_newlink+0x27/0x100 net/bridge/br_netlink.c:1563 rtnl_newlink_create net/core/rtnetlink.c:3497 [inline] __rtnl_newlink net/core/rtnetlink.c:3717 [inline] rtnl_newlink+0x158f/0x20a0 net/core/rtnetlink.c:3730 page last free pid 11583 tgid 11583 stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1140 [inline] free_unref_page_prepare+0x968/0xa90 mm/page_alloc.c:2346 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2486 kasan_depopulate_vmalloc_pte+0x74/0x90 mm/kasan/shadow.c:415 apply_to_pte_range mm/memory.c:2619 [inline] apply_to_pmd_range mm/memory.c:2663 [inline] apply_to_pud_range mm/memory.c:2699 [inline] apply_to_p4d_range mm/memory.c:2735 [inline] __apply_to_page_range+0x8ec/0xe40 mm/memory.c:2769 kasan_release_vmalloc+0x9a/0xb0 mm/kasan/shadow.c:532 __purge_vmap_area_lazy+0x163f/0x1a10 mm/vmalloc.c:1770 drain_vmap_area_work+0x40/0xd0 mm/vmalloc.c:1804 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242 Memory state around the buggy address: ffff88809a07fb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809a07fb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88809a07fc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809a07fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809a07fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 3b1137fe7482 ("net: ipv6: Change notifications for multipath add to RTA_MULTIPATH") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: David Ahern Reviewed-by: David Ahern --- net/ipv6/route.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index ea1dec8448fce8ccf29be650301e937cfce6bd7a..ef815ba583a8f4ed0ca523a13c515f108132a939 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5332,19 +5332,7 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, err_nh = NULL; list_for_each_entry(nh, &rt6_nh_list, next) { err = __ip6_ins_rt(nh->fib6_info, info, extack); - fib6_info_release(nh->fib6_info); - - if (!err) { - /* save reference to last route successfully inserted */ - rt_last = nh->fib6_info; - - /* save reference to first route for notification */ - if (!rt_notif) - rt_notif = nh->fib6_info; - } - /* nh->fib6_info is used or freed at this point, reset to NULL*/ - nh->fib6_info = NULL; if (err) { if (replace && nhn) NL_SET_ERR_MSG_MOD(extack, @@ -5352,6 +5340,12 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, err_nh = nh; goto add_errout; } + /* save reference to last route successfully inserted */ + rt_last = nh->fib6_info; + + /* save reference to first route for notification */ + if (!rt_notif) + rt_notif = nh->fib6_info; /* Because each route is added like a single route we remove * these flags after the first nexthop: if there is a collision, @@ -5412,8 +5406,7 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, cleanup: list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) { - if (nh->fib6_info) - fib6_info_release(nh->fib6_info); + fib6_info_release(nh->fib6_info); list_del(&nh->next); kfree(nh); }