Slacware64 current Intel Core i7 6GB RAM Since 3.6-rc2 (this is a regression from 3.6-rc1), I get the following warning when I ping a host: WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff8801c3f79460) 00000000030380ab00000000450000482881000080118ebbc0a8010bc0a8010d u u u u i i i i i i i i i i i i i i i i i i i i i i i i i i i i ^ Pid: 5836, comm: udev-acl.ck Not tainted 3.6.0-rc2 #3 Acer Aspire 7750G/JE70_HR RIP: 0010:[<ffffffff81697ed2>] [<ffffffff81697ed2>] __ip_select_ident+0x22/0x120 RSP: 0000:ffff8801c7e035e0 EFLAGS: 00010282 RAX: ffff88018194ab00 RBX: ffff88018b454700 RCX: 0000000000000040 RDX: 0000000000000001 RSI: ffff8801c7e035ec RDI: ffff8801c3f79450 RBP: ffff8801c7e03620 R08: ffff8801c54a8238 R09: 0000000000000000 R10: ffff8801c7e03770 R11: 0000000000000050 R12: ffff8801c3f79450 R13: 0000000000000000 R14: ffff88018db74a80 R15: ffff8801c3f79450 FS: 00007f0692dfb740(0000) GS:ffff8801c7e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8801c6b06a88 CR3: 00000001a9ae5000 CR4: 00000000000407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [<ffffffff816a2aa8>] __ip_make_skb+0x2f8/0x3c0 [<ffffffff816a2bd7>] ip_push_pending_frames+0x17/0x30 [<ffffffff816d16be>] icmp_push_reply+0xee/0x120 [<ffffffff816d1b95>] icmp_send+0x4a5/0xb10 [<ffffffff816ce5b8>] __udp4_lib_rcv+0x568/0x920 [<ffffffff816ce985>] udp_rcv+0x15/0x20 [<ffffffff8169b0d7>] ip_local_deliver_finish+0x107/0x460 [<ffffffff8169b6f8>] ip_local_deliver+0x88/0x90 [<ffffffff8169ab10>] ip_rcv_finish+0x120/0x5e0 [<ffffffff8169b919>] ip_rcv+0x219/0x2b0 [<ffffffff8164de82>] __netif_receive_skb+0x742/0x9b0 [<ffffffff8164ef68>] netif_receive_skb+0x28/0x1e0 [<ffffffff817a2de5>] ieee80211_deliver_skb.isra.28+0xa5/0x220 [<ffffffff817a3e87>] ieee80211_rx_handlers+0xf27/0x2380 [<ffffffff817a55e7>] ieee80211_prepare_and_rx_handle+0x307/0x8b0 [<ffffffff817a620e>] ieee80211_rx+0x67e/0xce0 [<ffffffff814b819c>] ath_rx_tasklet+0xc9c/0x1350 [<ffffffff814b6024>] ath9k_tasklet+0xe4/0x140 [<ffffffff810784ec>] tasklet_action+0x6c/0xe0 [<ffffffff81078e5a>] __do_softirq+0xba/0x180 [<ffffffff817e32dc>] call_softirq+0x1c/0x30 [<ffffffff8103a4ed>] do_softirq+0x7d/0xb0 [<ffffffff81079276>] irq_exit+0x96/0xc0 [<ffffffff81039f8e>] do_IRQ+0x5e/0xd0 [<ffffffff817e18ac>] ret_from_intr+0x0/0x13 [<ffffffffffffffff>] 0xffffffffffffffff This is a wireless network. gdb gives the following: (gdb) l *0xffffffff81697ed2 0xffffffff81697ed2 is in __ip_select_ident (include/net/inetpeer.h:145). 140 __be32 v4daddr, 141 int create) 142 { 143 struct inetpeer_addr daddr; 144 145 daddr.addr.a4 = v4daddr; 146 daddr.family = AF_INET; 147 return inet_getpeer(base, &daddr, create); 148 } 149 (gdb) l *0xffffffff816a2aa8 0xffffffff816a2aa8 is in __ip_make_skb (include/net/ip.h:264). 259 * a TCP stream using header compression. 260 */ 261 iph->id = (sk && inet_sk(sk)->inet_daddr) ? 262 htons(inet_sk(sk)->inet_id++) : 0; 263 } else 264 __ip_select_ident(iph, dst, 0); 265 } 266 267 static inline void ip_select_ident_more(struct iphdr *iph, struct dst_entry *dst, struct sock *sk, int more) 268 {
This is best reported to netdev@vger.kernel.org rather than just filed as a bug.
A patch referencing this bug report has been merged in Linux v3.6-rc3: commit a9915a1b52df52ad87f3b33422da95cf25372f09 Author: Eric Dumazet <edumazet@google.com> Date: Mon Aug 20 07:26:45 2012 +0000 ipv4: fix ip header ident selection in __ip_make_skb()