From: Pedro Tammela pctammela@mojatatu.com
[ Upstream commit 42018a322bd453e38b3ffee294982243e50a484f ]
Syzkaller found an issue where a handle greater than 16 bits would trigger a null-ptr-deref in the imperfect hash area update.
general protection fault, probably for non-canonical address 0xdffffc0000000015: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af] CPU: 0 PID: 5070 Comm: syz-executor456 Not tainted 6.2.0-rc7-syzkaller-00112-gc68f345b7c42 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 RIP: 0010:tcindex_set_parms+0x1a6a/0x2990 net/sched/cls_tcindex.c:509 Code: 01 e9 e9 fe ff ff 4c 8b bd 28 fe ff ff e8 0e 57 7d f9 48 8d bb a8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 94 0c 00 00 48 8b 85 f8 fd ff ff 48 8b 9b a8 00 RSP: 0018:ffffc90003d3ef88 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000015 RSI: ffffffff8803a102 RDI: 00000000000000a8 RBP: ffffc90003d3f1d8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801e2b10a8 R13: dffffc0000000000 R14: 0000000000030000 R15: ffff888017b3be00 FS: 00005555569af300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056041c6d2000 CR3: 000000002bfca000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcindex_change+0x1ea/0x320 net/sched/cls_tcindex.c:572 tc_new_tfilter+0x96e/0x2220 net/sched/cls_api.c:2155 rtnetlink_rcv_msg+0x959/0xca0 net/core/rtnetlink.c:6132 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x334/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmmsg+0x18f/0x460 net/socket.c:2616 __do_sys_sendmmsg net/socket.c:2645 [inline] __se_sys_sendmmsg net/socket.c:2642 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2642 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
Fixes: ee059170b1f7 ("net/sched: tcindex: update imperfect hash filters respecting rcu") Signed-off-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Pedro Tammela pctammela@mojatatu.com Reported-by: syzbot syzkaller@googlegroups.com Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/cls_tcindex.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c index 50bf7ec4b5b25..2c0c95204cb5a 100644 --- a/net/sched/cls_tcindex.c +++ b/net/sched/cls_tcindex.c @@ -502,7 +502,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, /* lookup the filter, guaranteed to exist */ for (cf = rcu_dereference_bh_rtnl(*fp); cf; fp = &cf->next, cf = rcu_dereference_bh_rtnl(*fp)) - if (cf->key == handle) + if (cf->key == (u16)handle) break;
f->next = cf->next;