From: Tommi Rantala Date: Thu, 29 Nov 2012 23:17:42 +0000 (+0000) Subject: sctp: fix CONFIG_SCTP_DBG_MSG=y null pointer dereference in sctp_v6_get_dst() X-Git-Tag: master-2012-12-14~5^2~160 X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=ee3f34e857238a4552c68d860348893d7728bcab;p=~andy%2Flinux sctp: fix CONFIG_SCTP_DBG_MSG=y null pointer dereference in sctp_v6_get_dst() Trinity (the syscall fuzzer) triggered the following BUG, reproducible only when the kernel is configured with CONFIG_SCTP_DBG_MSG=y. When CONFIG_SCTP_DBG_MSG is not set, the null pointer is never dereferenced. ---[ end trace a4de0bfcb38a3642 ]--- BUG: unable to handle kernel NULL pointer dereference at 0000000000000100 IP: [] ip6_string+0x1e/0xa0 PGD 4eead067 PUD 4e472067 PMD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: CPU 3 Pid: 21324, comm: trinity-child11 Tainted: G W 3.7.0-rc7+ #61 ASUSTeK Computer INC. EB1012/EB1012 RIP: 0010:[] [] ip6_string+0x1e/0xa0 RSP: 0018:ffff88004e4637a0 EFLAGS: 00010046 RAX: ffff88004e4637da RBX: ffff88004e4637da RCX: 0000000000000000 RDX: ffffffff8246e92a RSI: 0000000000000100 RDI: ffff88004e4637da RBP: ffff88004e4637a8 R08: 000000000000ffff R09: 000000000000ffff R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8289d600 R13: ffffffff8289d230 R14: ffffffff8246e928 R15: ffffffff8289d600 FS: 00007fed95153700(0000) GS:ffff88005fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000100 CR3: 000000004eeac000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process trinity-child11 (pid: 21324, threadinfo ffff88004e462000, task ffff8800524b0000) Stack: ffff88004e4637da ffff88004e463828 ffffffff81368eee 000000004e4637d8 ffffffff0000ffff ffff88000000ffff 0000000000000000 000000004e4637f8 ffffffff826285d8 ffff88004e4637f8 0000000000000000 ffff8800524b06b0 Call Trace: [] ip6_addr_string.isra.11+0x3e/0xa0 [] pointer.isra.12+0x233/0x2d0 [] ? vprintk_emit+0x1ba/0x450 [] ? trace_hardirqs_on_caller+0x10d/0x1a0 [] vsnprintf+0x187/0x5d0 [] vscnprintf+0x12/0x30 [] vprintk_emit+0xa8/0x450 [] printk+0x49/0x4b [] sctp_v6_get_dst+0x731/0x780 [] ? sctp_v6_get_dst+0x325/0x780 [] sctp_transport_route+0x46/0x120 [] sctp_assoc_add_peer+0x161/0x350 [] sctp_sendmsg+0x6cd/0xcb0 [] ? inet_create+0x670/0x670 [] inet_sendmsg+0x10b/0x220 [] ? inet_create+0x670/0x670 [] ? sock_update_classid+0xa4/0x2b0 [] ? sock_update_classid+0xf0/0x2b0 [] sock_sendmsg+0xdc/0xf0 [] ? might_fault+0x85/0x90 [] ? might_fault+0x3c/0x90 [] sys_sendto+0xfa/0x130 [] ? do_setitimer+0x197/0x380 [] ? sysret_check+0x22/0x5d [] system_call_fastpath+0x16/0x1b Code: 01 eb 89 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 f8 31 c9 48 89 e5 53 eb 12 0f 1f 40 00 48 83 c1 01 48 83 c0 04 48 83 f9 08 74 70 <0f> b6 3c 4e 89 fb 83 e7 0f c0 eb 04 41 89 d8 41 83 e0 0f 0f b6 RIP [] ip6_string+0x1e/0xa0 RSP CR2: 0000000000000100 ---[ end trace a4de0bfcb38a3643 ]--- Signed-off-by: Tommi Rantala Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index ea14cb44529..f3f0f4dc31d 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -345,7 +345,7 @@ static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, } out: - if (!IS_ERR(dst)) { + if (!IS_ERR_OR_NULL(dst)) { struct rt6_info *rt; rt = (struct rt6_info *)dst; t->dst = dst;