linux/net
Shyam Iyer 71b3346d18 net: Fix OOPS in skb_seq_read().
It oopsd for me in skb_seq_read. addr2line said it was
linux-2.6/net/core/skbuff.c:2228, which is this line:


	while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) {


I added some printks in there and it looks like we hit this:

        } else if (st->root_skb == st->cur_skb &&
                   skb_shinfo(st->root_skb)->frag_list) {
                 st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
                 st->frag_idx = 0;
                 goto next_skb;
        }



Actually I did some testing and added a few printks and found that the
st->cur_skb->data was 0 and hence the ptr used by iscsi_tcp was null.
This caused the kernel panic.

 	if (abs_offset < block_limit) {
-		*data = st->cur_skb->data + abs_offset;
+		*data = st->cur_skb->data + (abs_offset - st->stepped_offset);

I enabled the debug_tcp and with a few printks found that the code did
not go to the next_skb label and could find that the sequence being
followed was this -

It hit this if condition -

        if (st->cur_skb->next) {
                st->cur_skb = st->cur_skb->next;
                st->frag_idx = 0;
                goto next_skb;

And so, now the st pointer is shifted to the next skb whereas actually
it should have hit the second else if first since the data is in the
frag_list.

        else if (st->root_skb == st->cur_skb &&
                 skb_shinfo(st->root_skb)->frag_list) {
                st->cur_skb = skb_shinfo(st->root_skb)->frag_list;
                goto next_skb;
        }

Reversing the two conditions the attached patch fixes the issue for me
on top of Herbert's patches. 

Signed-off-by: Shyam Iyer <shyam_iyer@dell.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-29 16:12:42 -08:00
..
9p net/9p: fid->fid is used uninitialized 2009-01-19 16:20:15 -08:00
802 hippi: convert driver to net_device_ops 2008-11-20 20:32:15 -08:00
8021q vlan: Export symbols as non GPL symbols. 2009-01-26 12:37:53 -08:00
appletalk appletalk: convert aarp to net_device_ops 2009-01-07 17:21:44 -08:00
atm netdevice: Kill netdev->priv 2008-12-08 01:14:16 -08:00
ax25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2008-12-28 12:49:40 -08:00
bluetooth bluetooth: driver API update 2009-01-07 17:23:17 -08:00
bridge netfilter 05/09: ebtables: fix inversion in match code 2009-01-12 21:18:35 -08:00
can can: fix slowpath issue in hrtimer callback function 2009-01-14 21:06:55 -08:00
core net: Fix OOPS in skb_seq_read(). 2009-01-29 16:12:42 -08:00
dcb DCB: fix kfree(skb) 2009-01-04 17:29:21 -08:00
dccp dccp ccid-3: Fix RFC reference 2009-01-11 00:17:22 -08:00
decnet net: Make static 2008-12-10 15:18:31 -08:00
dsa dsa: convert to net_device_ops (v2) 2009-01-06 16:45:26 -08:00
econet netns: Use net_eq() to compare net-namespaces for optimization. 2008-07-19 22:34:43 -07:00
ethernet eth: Declare an optimized compare_ether_addr_64bits() function 2008-11-23 23:24:32 -08:00
ipv4 tcp: Fix length tcp_splice_data_recv passes to skb_splice_bits. 2009-01-26 22:15:31 -08:00
ipv6 ipv6: Make mc_forwarding sysctl read-only. 2009-01-27 22:41:03 -08:00
ipx net: '&' redux 2008-11-03 18:21:05 -08:00
irda tty: Fix an ircomm warning and note another bug 2009-01-02 10:19:43 -08:00
iucv s390: remove s390_root_dev_*() 2009-01-06 10:44:34 -08:00
key af_key: initialize xfrm encap_oa 2009-01-25 20:49:14 -08:00
lapb
llc net: remove redundant argument comments 2008-11-21 17:15:03 -08:00
mac80211 mac80211: fix slot time debug message 2009-01-22 13:55:01 -05:00
netfilter netfilter: ctnetlink: fix scheduling while atomic 2009-01-21 12:19:49 -08:00
netlabel netlabel: Update kernel configuration API 2008-12-31 12:54:11 -05:00
netlink genetlink: export genl_unregister_mc_group() 2009-01-07 10:00:17 -08:00
netrom Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2008-12-28 12:49:40 -08:00
packet net: Make sure BHs are disabled in sock_prot_inuse_add() 2008-11-24 00:09:29 -08:00
phonet phonet: update to net_device_ops 2009-01-07 17:24:34 -08:00
rfkill net/rfkill/rfkill.c: fix unused rfkill_led_trigger() warning 2009-01-04 17:11:24 -08:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2008-12-28 12:49:40 -08:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2008-12-28 12:49:40 -08:00
sched pkt_sched: sch_htb: Break all htb_do_events() after 2 jiffies 2009-01-12 21:54:40 -08:00
sctp sctp: Fix another socket race during accept/peeloff 2009-01-22 14:53:23 -08:00
sunrpc fs/Kconfig: move sunrpc out 2009-01-22 13:16:00 +03:00
tipc net/tipc/bcast.h: use ARRAY_SIZE 2009-01-11 00:06:33 -08:00
unix introduce new LSM hooks where vfsmount is available. 2008-12-31 18:07:37 -05:00
wanrouter netdevice wanrouter: Convert directly reference of netdev->priv 2008-11-20 04:26:21 -08:00
wimax wimax: testing for rfkill support should also test for CONFIG_RFKILL_MODULE 2009-01-08 11:08:01 -08:00
wireless cfg80211: print correct intersected regulatory domain 2009-01-29 15:46:43 -05:00
x25 net: '&' redux 2008-11-03 18:21:05 -08:00
xfrm Revert "xfrm: For 32/64 compatability wrt. xfrm_usersa_info" 2009-01-20 09:49:51 -08:00
compat.c reintroduce accept4 2008-11-19 18:49:57 -08:00
Kconfig net: Move config NET_NS to from net/Kconfig to init/Kconfig 2009-01-26 12:25:55 -08:00
Makefile wimax: Makefile, Kconfig and docbook linkage for the stack 2009-01-07 10:00:17 -08:00
nonet.c
socket.c [CVE-2009-0029] System call wrappers part 22 2009-01-14 14:15:27 +01:00
sysctl_net.c missing bits of net-namespace / sysctl 2008-07-27 09:45:34 -07:00
TUNABLE