4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 9b1f19d810e92d6cdc68455fbc22d9f961a58ce1 ]
Similarly to commit 276bdb82dedb ("dccp: check ccid before dereferencing") it is wise to test for a NULL ccid.
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: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.0.0-rc3+ #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ccid_hc_tx_parse_options net/dccp/ccid.h:205 [inline] RIP: 0010:dccp_parse_options+0x8d9/0x12b0 net/dccp/options.c:233 Code: c5 0f b6 75 b3 80 38 00 0f 85 d6 08 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 b8 4c 8b b8 f8 07 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 95 08 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b kobject: 'loop5' (0000000080f78fc1): kobject_uevent_env RSP: 0018:ffff8880a94df0b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880858ac723 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000007 RDI: 0000000000000001 RBP: ffff8880a94df140 R08: 0000000000000001 R09: ffff888061b83a80 R10: ffffed100c370752 R11: ffff888061b83a97 R12: 0000000000000026 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0defa33518 CR3: 000000008db5e000 CR4: 00000000001406e0 kobject: 'loop5' (0000000080f78fc1): fill_kobj_path: path = '/devices/virtual/block/loop5' DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dccp_rcv_state_process+0x2b6/0x1af6 net/dccp/input.c:654 dccp_v4_do_rcv+0x100/0x190 net/dccp/ipv4.c:688 sk_backlog_rcv include/net/sock.h:936 [inline] __sk_receive_skb+0x3a9/0xea0 net/core/sock.c:473 dccp_v4_rcv+0x10cb/0x1f80 net/dccp/ipv4.c:880 ip_protocol_deliver_rcu+0xb6/0xa20 net/ipv4/ip_input.c:208 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_local_deliver+0x1f0/0x740 net/ipv4/ip_input.c:255 dst_input include/net/dst.h:450 [inline] ip_rcv_finish+0x1f4/0x2f0 net/ipv4/ip_input.c:414 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_rcv+0xed/0x620 net/ipv4/ip_input.c:524 __netif_receive_skb_one_core+0x160/0x210 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083 process_backlog+0x206/0x750 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x76d/0x1930 net/core/dev.c:6412 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:654 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:646 smpboot_thread_fn+0x6ab/0xa10 kernel/smpboot.c:164 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Modules linked in: ---[ end trace 58a0ba03bea2c376 ]--- RIP: 0010:ccid_hc_tx_parse_options net/dccp/ccid.h:205 [inline] RIP: 0010:dccp_parse_options+0x8d9/0x12b0 net/dccp/options.c:233 Code: c5 0f b6 75 b3 80 38 00 0f 85 d6 08 00 00 48 b9 00 00 00 00 00 fc ff df 48 8b 45 b8 4c 8b b8 f8 07 00 00 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 95 08 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b RSP: 0018:ffff8880a94df0b8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8880858ac723 RCX: dffffc0000000000 RDX: 0000000000000100 RSI: 0000000000000007 RDI: 0000000000000001 RBP: ffff8880a94df140 R08: 0000000000000001 R09: ffff888061b83a80 R10: ffffed100c370752 R11: ffff888061b83a97 R12: 0000000000000026 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0defa33518 CR3: 0000000009871000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Cc: Gerrit Renker gerrit@erg.abdn.ac.uk Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/dccp/ccid.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/dccp/ccid.h +++ b/net/dccp/ccid.h @@ -202,7 +202,7 @@ static inline void ccid_hc_tx_packet_rec static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk, u8 pkt, u8 opt, u8 *val, u8 len) { - if (ccid->ccid_ops->ccid_hc_tx_parse_options == NULL) + if (!ccid || !ccid->ccid_ops->ccid_hc_tx_parse_options) return 0; return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len); } @@ -214,7 +214,7 @@ static inline int ccid_hc_tx_parse_optio static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk, u8 pkt, u8 opt, u8 *val, u8 len) { - if (ccid->ccid_ops->ccid_hc_rx_parse_options == NULL) + if (!ccid || !ccid->ccid_ops->ccid_hc_rx_parse_options) return 0; return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len); }