diff options
| author | Paolo Abeni | 2020-02-26 12:19:03 +0100 |
|---|---|---|
| committer | David S. Miller | 2020-02-26 20:49:50 -0800 |
| commit | dc24f8b4ecd3d6c4153a1ec1bc2006ab32a41b8d (patch) | |
| tree | a09ac86eeaa642f87dff19225f42ff5207f68bb9 /net | |
| parent | 4f31c532ad400a34dbdd836c204ed964d1ec2da5 (diff) | |
mptcp: add dummy icsk_sync_mss()
syzbot noted that the master MPTCP socket lacks the icsk_sync_mss
callback, and was able to trigger a null pointer dereference:
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 8e171067 P4D 8e171067 PUD 93fa2067 PMD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8984 Comm: syz-executor066 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffffc900020b7b80 EFLAGS: 00010246
RAX: 1ffff110124ba600 RBX: 0000000000000000 RCX: ffff88809fefa600
RDX: ffff8880994cdb18 RSI: 0000000000000000 RDI: ffff8880925d3140
RBP: ffffc900020b7bd8 R08: ffffffff870225be R09: fffffbfff140652a
R10: fffffbfff140652a R11: 0000000000000000 R12: ffff8880925d35d0
R13: ffff8880925d3140 R14: dffffc0000000000 R15: 1ffff110124ba6ba
FS: 0000000001a0b880(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000a6d6f000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
cipso_v4_sock_setattr+0x34b/0x470 net/ipv4/cipso_ipv4.c:1888
netlbl_sock_setattr+0x2a7/0x310 net/netlabel/netlabel_kapi.c:989
smack_netlabel security/smack/smack_lsm.c:2425 [inline]
smack_inode_setsecurity+0x3da/0x4a0 security/smack/smack_lsm.c:2716
security_inode_setsecurity+0xb2/0x140 security/security.c:1364
__vfs_setxattr_noperm+0x16f/0x3e0 fs/xattr.c:197
vfs_setxattr fs/xattr.c:224 [inline]
setxattr+0x335/0x430 fs/xattr.c:451
__do_sys_fsetxattr fs/xattr.c:506 [inline]
__se_sys_fsetxattr+0x130/0x1b0 fs/xattr.c:495
__x64_sys_fsetxattr+0xbf/0xd0 fs/xattr.c:495
do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440199
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcadc19e48 EFLAGS: 00000246 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440199
RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000003 R09: 00000000004002c8
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000401a20
R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
Address the issue adding a dummy icsk_sync_mss callback.
To properly sync the subflows mss and options list we need some
additional infrastructure, which will land to net-next.
Reported-by: syzbot+f4dfece964792d80b139@syzkaller.appspotmail.com
Fixes: 2303f994b3e1 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mptcp/protocol.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e9aa6807b5be..3c19a8efdcea 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -543,6 +543,11 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, } } +static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) +{ + return 0; +} + static int __mptcp_init_sock(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); @@ -551,6 +556,7 @@ static int __mptcp_init_sock(struct sock *sk) __set_bit(MPTCP_SEND_SPACE, &msk->flags); msk->first = NULL; + inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss; return 0; } |