Date: Wed, 05 Aug 2026 15:16:48 +0000 From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 6d9339c7b1b6 - stable/14 - inotify: Work around the vput() bug directly Message-ID: <6a7353e0.46d94.699a2707@gitrepo.freebsd.org>
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The branch stable/14 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=6d9339c7b1b60b97ea1e9391af31b7f4e8de0d00 commit 6d9339c7b1b60b97ea1e9391af31b7f4e8de0d00 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2025-11-15 18:00:44 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2026-08-05 15:15:16 +0000 inotify: Work around the vput() bug directly For 15.0, apply a minimal fix which at least ensures that inotify can't trigger the latent race described in commit 99cb3dca4773 ("vnode: Rework vput() to avoid holding the vnode lock after decrementing"). Reviewed by: olce, kib MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D53774 (cherry picked from commit ebc17879f0885ca87644980f6275b9759b311eb3) --- sys/kern/vfs_inotify.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/sys/kern/vfs_inotify.c b/sys/kern/vfs_inotify.c index eba2f0147409..6b82d5e9ab96 100644 --- a/sys/kern/vfs_inotify.c +++ b/sys/kern/vfs_inotify.c @@ -377,7 +377,14 @@ inotify_unlink_watch_locked(struct inotify_softc *sc, struct inotify_watch *watc static void inotify_free_watch(struct inotify_watch *watch) { - vrele(watch->vp); + /* + * Formally, we don't need to lock the vnode here. However, if we + * don't, and vrele() releases the last reference, it's possible the + * vnode will be recycled while a different thread holds the vnode lock. + * Work around this bug by acquiring the lock here. + */ + (void)vn_lock(watch->vp, LK_EXCLUSIVE | LK_RETRY); + vput(watch->vp); free(watch, M_INOTIFY); }home | help
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