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authorEric Dumazet <edumazet@google.com>2022-03-21 18:23:14 -0700
committerPaolo Abeni <pabeni@redhat.com>2022-03-22 12:47:51 +0100
commitcde3fc244b3d2e1bb32fc5869c718ec1cbb79481 (patch)
tree4a3ea842277a9a4567d80fea6e36963cb6f69d87 /net/bridge
parent7b17d2d7d7bf5add35f1e9067ef9450698eac85e (diff)
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net: bridge: mst: prevent NULL deref in br_mst_info_size()
Call br_mst_info_size() only if vg pointer is not NULL. general protection fault, probably for non-canonical address 0xdffffc0000000058: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000002c0-0x00000000000002c7] CPU: 0 PID: 975 Comm: syz-executor.0 Tainted: G W 5.17.0-next-20220321-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:br_mst_info_size+0x97/0x270 net/bridge/br_mst.c:242 Code: 00 00 31 c0 e8 ba 10 53 f9 31 c0 b9 40 00 00 00 4c 8d 6c 24 30 4c 89 ef f3 48 ab 48 8d 83 c0 02 00 00 48 89 04 24 48 c1 e8 03 <80> 3c 28 00 0f 85 ae 01 00 00 48 8b 83 c0 02 00 00 41 bf 04 00 00 RSP: 0018:ffffc900153770a8 EFLAGS: 00010202 RAX: 0000000000000058 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff88259876 RDI: ffffc900153772d8 RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8db68957 R10: ffffffff881f737b R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900153770d8 R14: 00000000000002a0 R15: 00000000ffffffff FS: 00007f18bbb6f700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001a80 CR3: 000000001a7d9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 00000000000000d8 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> br_get_link_af_size_filtered+0x6e9/0xc00 net/bridge/br_netlink.c:123 rtnl_link_get_af_size net/core/rtnetlink.c:598 [inline] if_nlmsg_size+0x40c/0xa50 net/core/rtnetlink.c:1040 rtnl_calcit.isra.0+0x25f/0x460 net/core/rtnetlink.c:3780 rtnetlink_rcv_msg+0xa65/0xb80 net/core/rtnetlink.c:5937 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2413 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f18baa89049 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f18bbb6f168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f18bab9bf60 RCX: 00007f18baa89049 RDX: 0000000000000000 RSI: 0000000020001a80 RDI: 0000000000000004 RBP: 00007f18baae308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffeedb2be2f R14: 00007f18bbb6f300 R15: 0000000000022000 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:br_mst_info_size+0x97/0x270 net/bridge/br_mst.c:242 Code: 00 00 31 c0 e8 ba 10 53 f9 31 c0 b9 40 00 00 00 4c 8d 6c 24 30 4c 89 ef f3 48 ab 48 8d 83 c0 02 00 00 48 89 04 24 48 c1 e8 03 <80> 3c 28 00 0f 85 ae 01 00 00 48 8b 83 c0 02 00 00 41 bf 04 00 00 RSP: 0018:ffffc900153770a8 EFLAGS: 00010202 RAX: 0000000000000058 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff88259876 RDI: ffffc900153772d8 RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8db68957 R10: ffffffff881f737b R11: 0000000000000000 R12: 0000000000000000 R13: ffffc900153770d8 R14: 00000000000002a0 R15: 00000000ffffffff FS: 00007f18bbb6f700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ca22000 CR3: 000000001a7d9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 00000000000000d8 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 122c29486e1f ("net: bridge: mst: Support setting and reporting MST port states") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tobias Waldekranz <tobias@waldekranz.com> Cc: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Tobias Waldekranz <tobias@waldekranz.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20220322012314.795187-1-eric.dumazet@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net/bridge')
-rw-r--r--net/bridge/br_netlink.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index a8d90fa8621e..204472449ec9 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -119,7 +119,7 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
/* Each VLAN is returned in bridge_vlan_info along with flags */
vinfo_sz += num_vlan_infos * nla_total_size(sizeof(struct bridge_vlan_info));
- if (filter_mask & RTEXT_FILTER_MST)
+ if (vg && (filter_mask & RTEXT_FILTER_MST))
vinfo_sz += br_mst_info_size(vg);
if (!(filter_mask & RTEXT_FILTER_CFM_STATUS))