* [PATCH AUTOSEL 4.19 1/2] af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register
@ 2022-03-21 21:53 Sasha Levin
2022-03-21 21:53 ` [PATCH AUTOSEL 4.19 2/2] net: ipv6: fix skb_over_panic in __ip6_append_data Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Sasha Levin @ 2022-03-21 21:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Haimin Zhang, TCS Robot, Steffen Klassert, Sasha Levin, davem,
kuba, pabeni, netdev
From: Haimin Zhang <tcs_kernel@tencent.com>
[ Upstream commit 9a564bccb78a76740ea9d75a259942df8143d02c ]
Add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register
to initialize the buffer of supp_skb to fix a kernel-info-leak issue.
1) Function pfkey_register calls compose_sadb_supported to request
a sk_buff. 2) compose_sadb_supported calls alloc_sbk to allocate
a sk_buff, but it doesn't zero it. 3) If auth_len is greater 0, then
compose_sadb_supported treats the memory as a struct sadb_supported and
begins to initialize. But it just initializes the field sadb_supported_len
and field sadb_supported_exttype without field sadb_supported_reserved.
Reported-by: TCS Robot <tcs_robot@tencent.com>
Signed-off-by: Haimin Zhang <tcs_kernel@tencent.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/key/af_key.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/key/af_key.c b/net/key/af_key.c
index c7d5a6015389..8ce513e08fd7 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1709,7 +1709,7 @@ static int pfkey_register(struct sock *sk, struct sk_buff *skb, const struct sad
xfrm_probe_algs();
- supp_skb = compose_sadb_supported(hdr, GFP_KERNEL);
+ supp_skb = compose_sadb_supported(hdr, GFP_KERNEL | __GFP_ZERO);
if (!supp_skb) {
if (hdr->sadb_msg_satype != SADB_SATYPE_UNSPEC)
pfk->registered &= ~(1<<hdr->sadb_msg_satype);
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 4.19 2/2] net: ipv6: fix skb_over_panic in __ip6_append_data
2022-03-21 21:53 [PATCH AUTOSEL 4.19 1/2] af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register Sasha Levin
@ 2022-03-21 21:53 ` Sasha Levin
0 siblings, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2022-03-21 21:53 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Tadeusz Struk, syzbot+e223cf47ec8ae183f2a0, Willem de Bruijn,
Jakub Kicinski, Sasha Levin, davem, yoshfuji, dsahern, pabeni,
netdev
From: Tadeusz Struk <tadeusz.struk@linaro.org>
[ Upstream commit 5e34af4142ffe68f01c8a9acae83300f8911e20c ]
Syzbot found a kernel bug in the ipv6 stack:
LINK: https://syzkaller.appspot.com/bug?id=205d6f11d72329ab8d62a610c44c5e7e25415580
The reproducer triggers it by sending a crafted message via sendmmsg()
call, which triggers skb_over_panic, and crashes the kernel:
skbuff: skb_over_panic: text:ffffffff84647fb4 len:65575 put:65575
head:ffff888109ff0000 data:ffff888109ff0088 tail:0x100af end:0xfec0
dev:<NULL>
Update the check that prevents an invalid packet with MTU equal
to the fregment header size to eat up all the space for payload.
The reproducer can be found here:
LINK: https://syzkaller.appspot.com/text?tag=ReproC&x=1648c83fb00000
Reported-by: syzbot+e223cf47ec8ae183f2a0@syzkaller.appspotmail.com
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20220310232538.1044947-1-tadeusz.struk@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/ip6_output.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index fd496bda7ec7..373df391dc93 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1325,8 +1325,8 @@ static int __ip6_append_data(struct sock *sk,
sizeof(struct frag_hdr) : 0) +
rt->rt6i_nfheader_len;
- if (mtu < fragheaderlen ||
- ((mtu - fragheaderlen) & ~7) + fragheaderlen < sizeof(struct frag_hdr))
+ if (mtu <= fragheaderlen ||
+ ((mtu - fragheaderlen) & ~7) + fragheaderlen <= sizeof(struct frag_hdr))
goto emsgsize;
maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2022-03-21 23:00 UTC | newest]
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2022-03-21 21:53 [PATCH AUTOSEL 4.19 1/2] af_key: add __GFP_ZERO flag for compose_sadb_supported in function pfkey_register Sasha Levin
2022-03-21 21:53 ` [PATCH AUTOSEL 4.19 2/2] net: ipv6: fix skb_over_panic in __ip6_append_data Sasha Levin
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