Date: Sat, 07 Feb 2026 00:58:29 +0000 From: Bjoern A. Zeeb <bz@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 94be5dbdfd22 - main - LinuxKPI: 802.11: catch possible NULL pointer deref with mt76 Message-ID: <69868e35.3497c.7cff2db@gitrepo.freebsd.org>
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The branch main has been updated by bz: URL: https://cgit.FreeBSD.org/src/commit/?id=94be5dbdfd22de4ec9ad699803ae18d9d209d824 commit 94be5dbdfd22de4ec9ad699803ae18d9d209d824 Author: Bjoern A. Zeeb <bz@FreeBSD.org> AuthorDate: 2026-02-04 22:46:47 +0000 Commit: Bjoern A. Zeeb <bz@FreeBSD.org> CommitDate: 2026-02-07 00:57:53 +0000 LinuxKPI: 802.11: catch possible NULL pointer deref with mt76 With mt76 we, for the first time, see that txstat->skb or txstat->info may not be filled in linuxkpi_ieee80211_tx_status_ext(). Guard for these cases checking for skb and info to be not NULL and assume a TX failure in case info is NULL. Sponsored by: The FreeBSD Foundation MFC after: 3 days --- sys/compat/linuxkpi/common/src/linux_80211.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/sys/compat/linuxkpi/common/src/linux_80211.c b/sys/compat/linuxkpi/common/src/linux_80211.c index 54571b28e2b8..0b732cb691c6 100644 --- a/sys/compat/linuxkpi/common/src/linux_80211.c +++ b/sys/compat/linuxkpi/common/src/linux_80211.c @@ -8304,6 +8304,9 @@ _lkpi_ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb, struct ieee80211_node *ni; struct mbuf *m; + if (skb == NULL) + return; + m = skb->m; skb->m = NULL; @@ -8329,13 +8332,13 @@ linuxkpi_ieee80211_tx_status_ext(struct ieee80211_hw *hw, struct ieee80211_tx_status *txstat) { struct sk_buff *skb; - struct ieee80211_tx_info *info; + struct ieee80211_tx_info *info, _info = { }; struct ieee80211_ratectl_tx_status txs; struct ieee80211_node *ni; int status; skb = txstat->skb; - if (skb->m != NULL) { + if (skb != NULL && skb->m != NULL) { struct mbuf *m; m = skb->m; @@ -8345,7 +8348,13 @@ linuxkpi_ieee80211_tx_status_ext(struct ieee80211_hw *hw, ni = NULL; } + /* + * If we have no info information on tx, set info to an all-zero struct + * to make the code (and debug output) simpler. + */ info = txstat->info; + if (info == NULL) + info = &_info; if (info->flags & IEEE80211_TX_STAT_ACK) { status = 0; /* No error. */ txs.status = IEEE80211_RATECTL_TX_SUCCESS; @@ -8410,7 +8419,8 @@ linuxkpi_ieee80211_tx_status_ext(struct ieee80211_hw *hw, if (txstat->free_list) { _lkpi_ieee80211_free_txskb(hw, skb, status); - list_add_tail(&skb->list, txstat->free_list); + if (skb != NULL) + list_add_tail(&skb->list, txstat->free_list); } else { linuxkpi_ieee80211_free_txskb(hw, skb, status); }home | help
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