The branch main has been updated by jah: URL: https://cgit.FreeBSD.org/src/commit/?id=880d180bb21c764aec6bd5bc8c0a6b07b8c2e199
commit 880d180bb21c764aec6bd5bc8c0a6b07b8c2e199 Author: Jason A. Harmening <[email protected]> AuthorDate: 2025-10-13 20:40:46 +0000 Commit: Jason A. Harmening <[email protected]> CommitDate: 2025-10-14 18:48:51 +0000 unionfs: fix NULL deref on closing an fd passed through SCM_RIGHTS If the last reference to an open file is contained in an SCM_RIGHTS message in a UNIX domain socket, and that message is discarded without being read out by the receiver, VOP_CLOSE will ultimately be called with ap->a_td == NULL. Change unionfs_close() to check for this condition instead of blindly passing the thread to unionfs_find_node_status() which will try to dereference it. Also add relevant asserts on the node status lookup paths. PR: 289700 Reported by: asomers Reviewed by: asomers, olce MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D53079 --- sys/fs/unionfs/union_subr.c | 2 ++ sys/fs/unionfs/union_vnops.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c index a14f9ca74305..b6d6db60ca3d 100644 --- a/sys/fs/unionfs/union_subr.c +++ b/sys/fs/unionfs/union_subr.c @@ -587,6 +587,7 @@ unionfs_find_node_status(struct unionfs_node *unp, struct thread *td) struct unionfs_node_status *unsp; pid_t pid; + MPASS(td != NULL); pid = td->td_proc->p_pid; ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), __func__); @@ -612,6 +613,7 @@ unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status *unsp; pid_t pid; + MPASS(td != NULL); pid = td->td_proc->p_pid; KASSERT(NULL != unspp, ("%s: NULL status", __func__)); diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c index 627b2f6e9a1d..26fa14603c85 100644 --- a/sys/fs/unionfs/union_vnops.c +++ b/sys/fs/unionfs/union_vnops.c @@ -814,7 +814,7 @@ unionfs_close(struct vop_close_args *ap) unp = VTOUNIONFS(vp); lvp = unp->un_lowervp; uvp = unp->un_uppervp; - unsp = unionfs_find_node_status(unp, td); + unsp = (td != NULL) ? unionfs_find_node_status(unp, td) : NULL; if (unsp == NULL || (unsp->uns_lower_opencnt <= 0 && unsp->uns_upper_opencnt <= 0)) {
