| Message ID | 20171207142300.7635-2-kleber.souza@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [SRU,Trusty,Zesty,1/1] scsi: scsi_transport_iscsi: fix the issue that iscsi_if_rx doesn't parse nlmsg properly | expand |
On 07/12/17 14:23, Kleber Sacilotto de Souza wrote: > From: Xin Long <lucien.xin@gmail.com> > > ChunYu found a kernel crash by syzkaller: > > [ 651.617875] kasan: CONFIG_KASAN_INLINE enabled > [ 651.618217] kasan: GPF could be caused by NULL-ptr deref or user memory access > [ 651.618731] general protection fault: 0000 [#1] SMP KASAN > [ 651.621543] CPU: 1 PID: 9539 Comm: scsi Not tainted 4.11.0.cov #32 > [ 651.621938] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 > [ 651.622309] task: ffff880117780000 task.stack: ffff8800a3188000 > [ 651.622762] RIP: 0010:skb_release_data+0x26c/0x590 > [...] > [ 651.627260] Call Trace: > [ 651.629156] skb_release_all+0x4f/0x60 > [ 651.629450] consume_skb+0x1a5/0x600 > [ 651.630705] netlink_unicast+0x505/0x720 > [ 651.632345] netlink_sendmsg+0xab2/0xe70 > [ 651.633704] sock_sendmsg+0xcf/0x110 > [ 651.633942] ___sys_sendmsg+0x833/0x980 > [ 651.637117] __sys_sendmsg+0xf3/0x240 > [ 651.638820] SyS_sendmsg+0x32/0x50 > [ 651.639048] entry_SYSCALL_64_fastpath+0x1f/0xc2 > > It's caused by skb_shared_info at the end of sk_buff was overwritten by > ISCSI_KEVENT_IF_ERROR when parsing nlmsg info from skb in iscsi_if_rx. > > During the loop if skb->len == nlh->nlmsg_len and both are sizeof(*nlh), > ev = nlmsg_data(nlh) will acutally get skb_shinfo(SKB) instead and set a > new value to skb_shinfo(SKB)->nr_frags by ev->type. > > This patch is to fix it by checking nlh->nlmsg_len properly there to > avoid over accessing sk_buff. > > Reported-by: ChunYu Wang <chunwang@redhat.com> > Signed-off-by: Xin Long <lucien.xin@gmail.com> > Acked-by: Chris Leech <cleech@redhat.com> > Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> > > CVE-2017-14489 > (cherry picked from commit c88f0e6b06f4092995688211a631bb436125d77b) > Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> > --- > drivers/scsi/scsi_transport_iscsi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c > index 8934f19bce8e..0190aeff5f7f 100644 > --- a/drivers/scsi/scsi_transport_iscsi.c > +++ b/drivers/scsi/scsi_transport_iscsi.c > @@ -3689,7 +3689,7 @@ iscsi_if_rx(struct sk_buff *skb) > uint32_t group; > > nlh = nlmsg_hdr(skb); > - if (nlh->nlmsg_len < sizeof(*nlh) || > + if (nlh->nlmsg_len < sizeof(*nlh) + sizeof(*ev) || > skb->len < nlh->nlmsg_len) { > break; > } > Clean upstream cherry pick, does what it says. Acked-by: Colin Ian King <colin.king@canonical.com>
Clean cherrypick for both T and Z.
Acked-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Applied to trusty and zesty master-next branches. Thanks. Cascardo. Applied-to: trusty/master-next Applied-to: zesty/master-next
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 8934f19bce8e..0190aeff5f7f 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -3689,7 +3689,7 @@ iscsi_if_rx(struct sk_buff *skb) uint32_t group; nlh = nlmsg_hdr(skb); - if (nlh->nlmsg_len < sizeof(*nlh) || + if (nlh->nlmsg_len < sizeof(*nlh) + sizeof(*ev) || skb->len < nlh->nlmsg_len) { break; }