From 7d6bc28cfe5c8e3a279b4b4bdeed6698b2702685 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 16 Jun 2025 11:21:15 -0700 Subject: atm: Revert atm_account_tx() if copy_from_iter_full() fails. commit 7851263998d4269125fd6cb3fdbfc7c6db853859 upstream. In vcc_sendmsg(), we account skb->truesize to sk->sk_wmem_alloc by atm_account_tx(). It is expected to be reverted by atm_pop_raw() later called by vcc->dev->ops->send(vcc, skb). However, vcc_sendmsg() misses the same revert when copy_from_iter_full() fails, and then we will leak a socket. Let's factorise the revert part as atm_return_tx() and call it in the failure path. Note that the corresponding sk_wmem_alloc operation can be found in alloc_tx() as of the blamed commit. $ git blame -L:alloc_tx net/atm/common.c c55fa3cccbc2c~ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Simon Horman Closes: https://lore.kernel.org/netdev/20250614161959.GR414686@horms.kernel.org/ Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250616182147.963333-3-kuni1840@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- include/linux/atmdev.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/atmdev.h') diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h index 9b02961d65ee..45f2f278b50a 100644 --- a/include/linux/atmdev.h +++ b/include/linux/atmdev.h @@ -249,6 +249,12 @@ static inline void atm_account_tx(struct atm_vcc *vcc, struct sk_buff *skb) ATM_SKB(skb)->atm_options = vcc->atm_options; } +static inline void atm_return_tx(struct atm_vcc *vcc, struct sk_buff *skb) +{ + WARN_ON_ONCE(refcount_sub_and_test(ATM_SKB(skb)->acct_truesize, + &sk_atm(vcc)->sk_wmem_alloc)); +} + static inline void atm_force_charge(struct atm_vcc *vcc,int truesize) { atomic_add(truesize, &sk_atm(vcc)->sk_rmem_alloc); -- cgit v1.2.3