| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 62/85] r8169: fix potential skb double free in an error path | Date | Tue, 17 Nov 2020 14:05:31 +0100 |
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From: Heiner Kallweit <hkallweit1@gmail.com>
[ Upstream commit cc6528bc9a0c901c83b8220a2e2617f3354d6dd9 ]
The caller of rtl8169_tso_csum_v2() frees the skb if false is returned. eth_skb_pad() internally frees the skb on error what would result in a double free. Therefore use __skb_put_padto() directly and instruct it to not free the skb on error.
Fixes: b423e9ae49d7 ("r8169: fix offloaded tx checksum for small packets.") Reported-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Link: https://lore.kernel.org/r/f7e68191-acff-9ded-4263-c016428a8762@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/ethernet/realtek/r8169.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -7143,7 +7143,8 @@ static bool rtl8169_tso_csum_v2(struct r opts[1] |= transport_offset << TCPHO_SHIFT; } else { if (unlikely(rtl_test_hw_pad_bug(tp, skb))) - return !eth_skb_pad(skb); + /* eth_skb_pad would free the skb on error */ + return !__skb_put_padto(skb, ETH_ZLEN, false); } return true;
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