Revision dc24f8b4ecd3d6c4153a1ec1bc2006ab32a41b8d authored by Paolo Abeni on 26 February 2020, 11:19:03 UTC, committed by David S. Miller on 27 February 2020, 04:49:50 UTC
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>
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File | Mode | Size |
---|---|---|
6lowpan | ||
802 | ||
8021q | ||
9p | ||
appletalk | ||
atm | ||
ax25 | ||
batman-adv | ||
bluetooth | ||
bpf | ||
bpfilter | ||
bridge | ||
caif | ||
can | ||
ceph | ||
core | ||
dcb | ||
dccp | ||
decnet | ||
dns_resolver | ||
dsa | ||
ethernet | ||
ethtool | ||
hsr | ||
ieee802154 | ||
ife | ||
ipv4 | ||
ipv6 | ||
iucv | ||
kcm | ||
key | ||
l2tp | ||
l3mdev | ||
lapb | ||
llc | ||
mac80211 | ||
mac802154 | ||
mpls | ||
mptcp | ||
ncsi | ||
netfilter | ||
netlabel | ||
netlink | ||
netrom | ||
nfc | ||
nsh | ||
openvswitch | ||
packet | ||
phonet | ||
psample | ||
qrtr | ||
rds | ||
rfkill | ||
rose | ||
rxrpc | ||
sched | ||
sctp | ||
smc | ||
strparser | ||
sunrpc | ||
switchdev | ||
tipc | ||
tls | ||
unix | ||
vmw_vsock | ||
wimax | ||
wireless | ||
x25 | ||
xdp | ||
xfrm | ||
Kconfig | -rw-r--r-- | 14.1 KB |
Makefile | -rw-r--r-- | 2.5 KB |
compat.c | -rw-r--r-- | 22.5 KB |
socket.c | -rw-r--r-- | 95.2 KB |
sysctl_net.c | -rw-r--r-- | 3.0 KB |
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