4.17-stable review patch. If anyone has any objections, please let me know.
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From: Stefano Brivio sbrivio@redhat.com
[ Upstream commit e78bfb0751d4e312699106ba7efbed2bab1a53ca ]
Commit 8b7008620b84 ("net: Don't copy pfmemalloc flag in __copy_skb_header()") introduced a different handling for the pfmemalloc flag in copy and clone paths.
In __skb_clone(), now, the flag is set only if it was set in the original skb, but not cleared if it wasn't. This is wrong and might lead to socket buffers being flagged with pfmemalloc even if the skb data wasn't allocated from pfmemalloc reserves. Copy the flag instead of ORing it.
Reported-by: Sabrina Dubroca sd@queasysnail.net Fixes: 8b7008620b84 ("net: Don't copy pfmemalloc flag in __copy_skb_header()") Signed-off-by: Stefano Brivio sbrivio@redhat.com Tested-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/skbuff.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -858,8 +858,7 @@ static struct sk_buff *__skb_clone(struc n->cloned = 1; n->nohdr = 0; n->peeked = 0; - if (skb->pfmemalloc) - n->pfmemalloc = 1; + C(pfmemalloc); n->destructor = NULL; C(tail); C(end);