This is a note to let you know that I've just added the patch titled
net: llc: fix use after free in llc_ui_recvmsg
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-llc-fix-use-after-free-in-llc_ui_recvmsg.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From foo@baz Mon Jan 13 09:39:01 PST 2014
From: Daniel Borkmann <[email protected]>
Date: Mon, 30 Dec 2013 23:40:50 +0100
Subject: net: llc: fix use after free in llc_ui_recvmsg
From: Daniel Borkmann <[email protected]>
[ Upstream commit 4d231b76eef6c4a6bd9c96769e191517765942cb ]
While commit 30a584d944fb fixes datagram interface in LLC, a use
after free bug has been introduced for SOCK_STREAM sockets that do
not make use of MSG_PEEK.
The flow is as follow ...
if (!(flags & MSG_PEEK)) {
...
sk_eat_skb(sk, skb, false);
...
}
...
if (used + offset < skb->len)
continue;
... where sk_eat_skb() calls __kfree_skb(). Therefore, cache
original length and work on skb_len to check partial reads.
Fixes: 30a584d944fb ("[LLX]: SOCK_DGRAM interface fixes")
Signed-off-by: Daniel Borkmann <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
net/llc/af_llc.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -715,7 +715,7 @@ static int llc_ui_recvmsg(struct kiocb *
unsigned long cpu_flags;
size_t copied = 0;
u32 peek_seq = 0;
- u32 *seq;
+ u32 *seq, skb_len;
unsigned long used;
int target; /* Read at least this many bytes */
long timeo;
@@ -812,6 +812,7 @@ static int llc_ui_recvmsg(struct kiocb *
}
continue;
found_ok_skb:
+ skb_len = skb->len;
/* Ok so how much can we use? */
used = skb->len - offset;
if (len < used)
@@ -844,7 +845,7 @@ static int llc_ui_recvmsg(struct kiocb *
}
/* Partial read */
- if (used + offset < skb->len)
+ if (used + offset < skb_len)
continue;
} while (len > 0);
Patches currently in stable-queue which might be from [email protected] are
queue-3.10/net-inet_diag-zero-out-uninitialized-idiag_-src-dst-fields.patch
queue-3.10/packet-fix-send-path-when-running-with-proto-0.patch
queue-3.10/net-llc-fix-use-after-free-in-llc_ui_recvmsg.patch
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