From: Eric Dumazet <[email protected]>
Upstream commit:
ipv6: orphan skbs in reassembly unit
Andrey reported a use-after-free in IPv6 stack.
Issue here is that we free the socket while it still has skb
in TX path and in some queues.
It happens here because IPv6 reassembly unit messes skb->truesize,
breaking skb_set_owner_w() badly.
We fixed a similar issue for IPV4 in commit 8282f27449bf ("inet: frag:
Always orphan skbs inside ip_defrag()")
Acked-by: Joe Stringer <[email protected]>
==================================================================
BUG: KASAN: use-after-free in sock_wfree+0x118/0x120
Read of size 8 at addr ffff880062da0060 by task a.out/4140
page:ffffea00018b6800 count:1 mapcount:0 mapping: (null)
index:0x0 compound_mapcount: 0
flags: 0x100000000008100(slab|head)
raw: 0100000000008100 0000000000000000 0000000000000000 0000000180130013
raw: dead000000000100 dead000000000200 ffff88006741f140 0000000000000000
page dumped because: kasan: bad access detected
CPU: 0 PID: 4140 Comm: a.out Not tainted 4.10.0-rc3+ #59
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:15
dump_stack+0x292/0x398 lib/dump_stack.c:51
describe_address mm/kasan/report.c:262
kasan_report_error+0x121/0x560 mm/kasan/report.c:370
kasan_report mm/kasan/report.c:392
__asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:413
sock_flag ./arch/x86/include/asm/bitops.h:324
sock_wfree+0x118/0x120 net/core/sock.c:1631
skb_release_head_state+0xfc/0x250 net/core/skbuff.c:655
skb_release_all+0x15/0x60 net/core/skbuff.c:668
__kfree_skb+0x15/0x20 net/core/skbuff.c:684
kfree_skb+0x16e/0x4e0 net/core/skbuff.c:705
inet_frag_destroy+0x121/0x290 net/ipv4/inet_fragment.c:304
inet_frag_put ./include/net/inet_frag.h:133
nf_ct_frag6_gather+0x1125/0x38b0
net/ipv6/netfilter/nf_conntrack_reasm.c:617
ipv6_defrag+0x21b/0x350 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68
nf_hook_entry_hookfn ./include/linux/netfilter.h:102
nf_hook_slow+0xc3/0x290 net/netfilter/core.c:310
nf_hook ./include/linux/netfilter.h:212
__ip6_local_out+0x52c/0xaf0 net/ipv6/output_core.c:160
ip6_local_out+0x2d/0x170 net/ipv6/output_core.c:170
ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1722
ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1742
rawv6_push_pending_frames net/ipv6/raw.c:613
rawv6_sendmsg+0x2cff/0x4130 net/ipv6/raw.c:927
inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744
sock_sendmsg_nosec net/socket.c:635
sock_sendmsg+0xca/0x110 net/socket.c:645
sock_write_iter+0x326/0x620 net/socket.c:848
new_sync_write fs/read_write.c:499
__vfs_write+0x483/0x760 fs/read_write.c:512
vfs_write+0x187/0x530 fs/read_write.c:560
SYSC_write fs/read_write.c:607
SyS_write+0xfb/0x230 fs/read_write.c:599
entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203
RIP: 0033:0x7ff26e6f5b79
RSP: 002b:00007ff268e0ed98 EFLAGS: 00000206 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff268e0f9c0 RCX: 00007ff26e6f5b79
RDX: 0000000000000010 RSI: 0000000020f50fe1 RDI: 0000000000000003
RBP: 00007ff26ebc1220 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ff268e0f9c0 R14: 00007ff26efec040 R15: 0000000000000003
The buggy address belongs to the object at ffff880062da0000
which belongs to the cache RAWv6 of size 1504
The buggy address ffff880062da0060 is located 96 bytes inside
of 1504-byte region [ffff880062da0000, ffff880062da05e0)
Freed by task 4113:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
save_stack+0x43/0xd0 mm/kasan/kasan.c:502
set_track mm/kasan/kasan.c:514
kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:578
slab_free_hook mm/slub.c:1352
slab_free_freelist_hook mm/slub.c:1374
slab_free mm/slub.c:2951
kmem_cache_free+0xb2/0x2c0 mm/slub.c:2973
sk_prot_free net/core/sock.c:1377
__sk_destruct+0x49c/0x6e0 net/core/sock.c:1452
sk_destruct+0x47/0x80 net/core/sock.c:1460
__sk_free+0x57/0x230 net/core/sock.c:1468
sk_free+0x23/0x30 net/core/sock.c:1479
sock_put ./include/net/sock.h:1638
sk_common_release+0x31e/0x4e0 net/core/sock.c:2782
rawv6_close+0x54/0x80 net/ipv6/raw.c:1214
inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425
inet6_release+0x50/0x70 net/ipv6/af_inet6.c:431
sock_release+0x8d/0x1e0 net/socket.c:599
sock_close+0x16/0x20 net/socket.c:1063
__fput+0x332/0x7f0 fs/file_table.c:208
____fput+0x15/0x20 fs/file_table.c:244
task_work_run+0x19b/0x270 kernel/task_work.c:116
exit_task_work ./include/linux/task_work.h:21
do_exit+0x186b/0x2800 kernel/exit.c:839
do_group_exit+0x149/0x420 kernel/exit.c:943
SYSC_exit_group kernel/exit.c:954
SyS_exit_group+0x1d/0x20 kernel/exit.c:952
entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203
Allocated by task 4115:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
save_stack+0x43/0xd0 mm/kasan/kasan.c:502
set_track mm/kasan/kasan.c:514
kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:605
kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544
slab_post_alloc_hook mm/slab.h:432
slab_alloc_node mm/slub.c:2708
slab_alloc mm/slub.c:2716
kmem_cache_alloc+0x1af/0x250 mm/slub.c:2721
sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1334
sk_alloc+0x105/0x1010 net/core/sock.c:1396
inet6_create+0x44d/0x1150 net/ipv6/af_inet6.c:183
__sock_create+0x4f6/0x880 net/socket.c:1199
sock_create net/socket.c:1239
SYSC_socket net/socket.c:1269
SyS_socket+0xf9/0x230 net/socket.c:1249
entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203
Memory state around the buggy address:
ffff880062d9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff880062d9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff880062da0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff880062da0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff880062da0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Reported-by: Andrey Konovalov <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
This patch is a bugfix, and will be progressively backported to earlier
kernels. If it is backported to any kernel 4.5 through 4.10, then users
use that updated kernel with the OVS kernel module prior to this patch, it
could cause a crash. The compat code here resolves such issues.
Upstream: 48cac18ecf1d ("ipv6: orphan skbs in reassembly unit")
Signed-off-by: Joe Stringer <[email protected]>
Signed-off-by: Andy Zhou <[email protected]>
---
v1->v2: Drop nf_ct_frag6_gather__(), rename as rpl_nf_ct_frag6_gather()
---
AUTHORS.rst | 1 +
acinclude.m4 | 4 ----
datapath/conntrack.c | 1 -
.../linux/compat/include/net/netfilter/ipv6/nf_defrag_ipv6.h | 11 +++++++----
datapath/linux/compat/nf_conntrack_reasm.c | 3 ++-
5 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/AUTHORS.rst b/AUTHORS.rst
index a8592f063f77..39bbd2c92613 100644
--- a/AUTHORS.rst
+++ b/AUTHORS.rst
@@ -116,6 +116,7 @@ Aymerich Edward [email protected]
Edward Tomasz Napierała [email protected]
Eitan Eliahu [email protected]
Eohyung Lee [email protected]
+Eric Dumazet [email protected]
Eric Garver [email protected]
Eric Sesterhenn [email protected]
Ethan J. Jackson [email protected]
diff --git a/acinclude.m4 b/acinclude.m4
index 744d8f89525c..a7aaf48b5d2f 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -548,10 +548,6 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
[OVS_DEFINE([HAVE_NF_CONNLABELS_GET_TAKES_BIT])])
OVS_FIND_FIELD_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_labels.h],
[nf_conn_labels], [words])
- OVS_GREP_IFELSE([$KSRC/include/net/netfilter/ipv6/nf_defrag_ipv6.h],
- [nf_ct_frag6_consume_orig])
- OVS_GREP_IFELSE([$KSRC/include/net/netfilter/ipv6/nf_defrag_ipv6.h],
- [nf_ct_frag6_output])
OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h], [nf_ct_nat_ext_add])
OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h],
[nf_nat_alloc_null_binding])
OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_seqadj.h],
[nf_ct_seq_adjust])
diff --git a/datapath/conntrack.c b/datapath/conntrack.c
index 99a0201cc189..109b2970cc85 100644
--- a/datapath/conntrack.c
+++ b/datapath/conntrack.c
@@ -519,7 +519,6 @@ static int handle_fragments(struct net *net, struct
sw_flow_key *key,
} else if (key->eth.type == htons(ETH_P_IPV6)) {
enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
- skb_orphan(skb);
memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
err = nf_ct_frag6_gather(net, skb, user);
if (err) {
diff --git a/datapath/linux/compat/include/net/netfilter/ipv6/nf_defrag_ipv6.h
b/datapath/linux/compat/include/net/netfilter/ipv6/nf_defrag_ipv6.h
index c65e7f2feb03..2ab6c0aa79a1 100644
--- a/datapath/linux/compat/include/net/netfilter/ipv6/nf_defrag_ipv6.h
+++ b/datapath/linux/compat/include/net/netfilter/ipv6/nf_defrag_ipv6.h
@@ -5,11 +5,14 @@
#include_next <net/netfilter/ipv6/nf_defrag_ipv6.h>
/* Upstream commit 029f7f3b8701 ("netfilter: ipv6: nf_defrag: avoid/free clone
- * operations") changed the semantics of nf_ct_frag6_gather(), so we backport
- * it for all prior kernels.
+ * operations") changed the semantics of nf_ct_frag6_gather(), so we need
+ * to backport for all prior kernels, i.e. kernel < 4.5.0.
+ *
+ * Upstream commit 48cac18ecf1d ("ipv6: orphan skbs in reassembly unit") fixes
+ * a bug that requires all kernels prior to this fix, i.e. kernel < 4.11.0
+ * to be backported.
*/
-#if defined(HAVE_NF_CT_FRAG6_CONSUME_ORIG) || \
- defined(HAVE_NF_CT_FRAG6_OUTPUT)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,11,0)
#define OVS_NF_DEFRAG6_BACKPORT 1
int rpl_nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user);
#define nf_ct_frag6_gather rpl_nf_ct_frag6_gather
diff --git a/datapath/linux/compat/nf_conntrack_reasm.c
b/datapath/linux/compat/nf_conntrack_reasm.c
index e633443d16e0..0bc4d9e4816c 100644
--- a/datapath/linux/compat/nf_conntrack_reasm.c
+++ b/datapath/linux/compat/nf_conntrack_reasm.c
@@ -498,7 +498,7 @@ find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int
*prevhoff, int *fhoff)
return 0;
}
-int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
+int rpl_nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
{
struct net_device *dev = skb->dev;
int fhoff, nhoff, ret;
@@ -530,6 +530,7 @@ int nf_ct_frag6_gather(struct net *net, struct sk_buff
*skb, u32 user)
local_bh_enable();
#endif
+ skb_orphan(skb);
fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr,
ip6_frag_ecn(hdr));
if (fq == NULL)
--
1.8.3.1
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