diff options
| author | Jason A. Harmening <jah@FreeBSD.org> | 2025-10-13 20:40:46 +0000 |
|---|---|---|
| committer | Jason A. Harmening <jah@FreeBSD.org> | 2025-10-14 18:48:51 +0000 |
| commit | 880d180bb21c764aec6bd5bc8c0a6b07b8c2e199 (patch) | |
| tree | d7fb192e62c51bf3a0b59ef877abce8b5ffcd400 | |
| parent | 86d17239233ea4f5766bee68ba6355804525cefa (diff) | |
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
| -rw-r--r-- | sys/fs/unionfs/union_subr.c | 2 | ||||
| -rw-r--r-- | sys/fs/unionfs/union_vnops.c | 2 |
2 files changed, 3 insertions, 1 deletions
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)) { |