This is a note to let you know that I've just added the patch titled
netfilter: nf_osf: avoid passing pointer to local var
to the 5.6-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:
netfilter-nf_osf-avoid-passing-pointer-to-local-var.patch
and it can be found in the queue-5.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c165d57b552aaca607fa5daf3fb524a6efe3c5a3 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Wed, 29 Apr 2020 21:00:41 +0200
Subject: netfilter: nf_osf: avoid passing pointer to local var
From: Arnd Bergmann <arnd@xxxxxxxx>
commit c165d57b552aaca607fa5daf3fb524a6efe3c5a3 upstream.
gcc-10 points out that a code path exists where a pointer to a stack
variable may be passed back to the caller:
net/netfilter/nfnetlink_osf.c: In function 'nf_osf_hdr_ctx_init':
cc1: warning: function may return address of local variable [-Wreturn-local-addr]
net/netfilter/nfnetlink_osf.c:171:16: note: declared here
171 | struct tcphdr _tcph;
| ^~~~~
I am not sure whether this can happen in practice, but moving the
variable declaration into the callers avoids the problem.
Fixes: 31a9c29210e2 ("netfilter: nf_osf: add struct nf_osf_hdr_ctx")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/nfnetlink_osf.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- a/net/netfilter/nfnetlink_osf.c
+++ b/net/netfilter/nfnetlink_osf.c
@@ -165,12 +165,12 @@ static bool nf_osf_match_one(const struc
static const struct tcphdr *nf_osf_hdr_ctx_init(struct nf_osf_hdr_ctx *ctx,
const struct sk_buff *skb,
const struct iphdr *ip,
- unsigned char *opts)
+ unsigned char *opts,
+ struct tcphdr *_tcph)
{
const struct tcphdr *tcp;
- struct tcphdr _tcph;
- tcp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(struct tcphdr), &_tcph);
+ tcp = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(struct tcphdr), _tcph);
if (!tcp)
return NULL;
@@ -205,10 +205,11 @@ nf_osf_match(const struct sk_buff *skb,
int fmatch = FMATCH_WRONG;
struct nf_osf_hdr_ctx ctx;
const struct tcphdr *tcp;
+ struct tcphdr _tcph;
memset(&ctx, 0, sizeof(ctx));
- tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts);
+ tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts, &_tcph);
if (!tcp)
return false;
@@ -265,10 +266,11 @@ bool nf_osf_find(const struct sk_buff *s
const struct nf_osf_finger *kf;
struct nf_osf_hdr_ctx ctx;
const struct tcphdr *tcp;
+ struct tcphdr _tcph;
memset(&ctx, 0, sizeof(ctx));
- tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts);
+ tcp = nf_osf_hdr_ctx_init(&ctx, skb, ip, opts, &_tcph);
if (!tcp)
return false;
Patches currently in stable-queue which might be from arnd@xxxxxxxx are
queue-5.6/netfilter-nf_osf-avoid-passing-pointer-to-local-var.patch
queue-5.6/amba-initialize-dma_parms-for-amba-devices.patch
queue-5.6/driver-core-platform-initialize-dma_parms-for-platform-devices.patch
