Messages in this thread Patch in this message | | | Subject | [PATCH v2 10/19] ipv4: prevent bounds-check bypass via speculative execution | From | Dan Williams <> | Date | Thu, 11 Jan 2018 16:47:18 -0800 |
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Static analysis reports that 'offset' may be a user controlled value that is used as a data dependency reading from a raw_frag_vec buffer. In order to avoid potential leaks of kernel memory values, block speculative execution of the instruction stream that could issue further reads based on an invalid '*(rfv->c + offset)' value.
Based on an original patch by Elena Reshetova.
Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: netdev@vger.kernel.org Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- net/ipv4/raw.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 125c1eab3eaa..91091a10294f 100644 --- a/net/ipv4/raw.c +++ b/net/ipv4/raw.c @@ -57,6 +57,7 @@ #include <linux/in_route.h> #include <linux/route.h> #include <linux/skbuff.h> +#include <linux/nospec.h> #include <linux/igmp.h> #include <net/net_namespace.h> #include <net/dst.h> @@ -472,17 +473,18 @@ static int raw_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) { struct raw_frag_vec *rfv = from; + char *rfv_buf; - if (offset < rfv->hlen) { + rfv_buf = array_ptr(rfv->hdr.c, offset, rfv->hlen); + if (rfv_buf) { int copy = min(rfv->hlen - offset, len); if (skb->ip_summed == CHECKSUM_PARTIAL) - memcpy(to, rfv->hdr.c + offset, copy); + memcpy(to, rfv_buf, copy); else skb->csum = csum_block_add( skb->csum, - csum_partial_copy_nocheck(rfv->hdr.c + offset, - to, copy, 0), + csum_partial_copy_nocheck(rfv_buf, to, copy, 0), odd); odd = 0;
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