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authorEric Dumazet <edumazet@google.com>2018-10-26 09:33:27 -0700
committerDavid S. Miller <davem@davemloft.net>2018-10-26 16:03:51 -0700
commitaab456dfa404f3a16d6f1780e62a6a8533c4d008 (patch)
tree0694ea386567f9b411c5d9f41aaa1ffe84bb5c97 /net
parentnet: allow traceroute with a specified interface in a vrf (diff)
downloadlinux-dev-aab456dfa404f3a16d6f1780e62a6a8533c4d008.tar.xz
linux-dev-aab456dfa404f3a16d6f1780e62a6a8533c4d008.zip
net/neigh: fix NULL deref in pneigh_dump_table()
pneigh can have NULL device pointer, so we need to make neigh_master_filtered() and neigh_ifindex_filtered() more robust. syzbot report : kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 15867 Comm: syz-executor2 Not tainted 4.19.0+ #276 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:179 [inline] RIP: 0010:list_empty include/linux/list.h:203 [inline] RIP: 0010:netdev_master_upper_dev_get+0xa1/0x250 net/core/dev.c:6467 RSP: 0018:ffff8801bfaf7220 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffc90005e92000 RDX: 0000000000000016 RSI: ffffffff860b44d9 RDI: 0000000000000005 RBP: ffff8801bfaf72b0 R08: ffff8801c4c84080 R09: fffffbfff139a580 R10: fffffbfff139a580 R11: ffffffff89cd2c07 R12: 1ffff10037f5ee45 R13: 0000000000000000 R14: ffff8801bfaf7288 R15: 00000000000000b0 FS: 00007f65cc68d700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33a21000 CR3: 00000001c6116000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: neigh_master_filtered net/core/neighbour.c:2367 [inline] pneigh_dump_table net/core/neighbour.c:2456 [inline] neigh_dump_info+0x7a9/0x1ce0 net/core/neighbour.c:2577 netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244 __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352 netlink_dump_start include/linux/netlink.h:216 [inline] rtnetlink_rcv_msg+0x809/0xc20 net/core/rtnetlink.c:4898 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4953 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 sock_write_iter+0x35e/0x5c0 net/socket.c:900 call_write_iter include/linux/fs.h:1808 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Fixes: 6f52f80e8530 ("net/neigh: Extend dump filter to proxy neighbor dumps") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: David Ahern <dsahern@gmail.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: David Ahern <dsahern@gmail.com> Tested-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/neighbour.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index ee605d9d8bd4..41954e42a2de 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2364,7 +2364,7 @@ static bool neigh_master_filtered(struct net_device *dev, int master_idx)
if (!master_idx)
return false;
- master = netdev_master_upper_dev_get(dev);
+ master = dev ? netdev_master_upper_dev_get(dev) : NULL;
if (!master || master->ifindex != master_idx)
return true;
@@ -2373,7 +2373,7 @@ static bool neigh_master_filtered(struct net_device *dev, int master_idx)
static bool neigh_ifindex_filtered(struct net_device *dev, int filter_idx)
{
- if (filter_idx && dev->ifindex != filter_idx)
+ if (filter_idx && (!dev || dev->ifindex != filter_idx))
return true;
return false;