git: 45456abc4ce7 - main - cache: fix trailing slash support in face of permission problems

[Mateusz Guzik]

The branch main has been updated by mjg:

URL: https://cgit.FreeBSD.org/src/commit/?id=45456abc4ce71053d07cf03ca63bd1ce459fec55

commit 45456abc4ce71053d07cf03ca63bd1ce459fec55
Author:     Mateusz Guzik <mjg at FreeBSD.org>
AuthorDate: 2021-02-02 18:06:56 +0000
Commit:     Mateusz Guzik <mjg at FreeBSD.org>
CommitDate: 2021-02-02 18:13:51 +0000

    cache: fix trailing slash support in face of permission problems
    
    Reported by:    Johan Hendriks <joh.hendriks gmail.com>
    Tested by:      kevans
---
 sys/kern/vfs_cache.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c
index 7f0e59f1a1ee..db482ea4eba3 100644
--- a/sys/kern/vfs_cache.c
+++ b/sys/kern/vfs_cache.c
@@ -5521,6 +5521,16 @@ cache_fplookup_failed_vexec(struct cache_fpl *fpl, int error)
 	dvp = fpl->dvp;
 	dvp_seqc = fpl->dvp_seqc;
 
+	/*
+	 * TODO: Due to ignoring slashes lookup will perform a permission check
+	 * on the last dir when it should not have. If it fails, we get here.
+	 * It is possible possible to fix it up fully without resorting to
+	 * regular lookup, but for now just abort.
+	 */
+	if (cache_fpl_istrailingslash(fpl)) {
+		return (cache_fpl_aborted(fpl));
+	}
+
 	/*
 	 * Hack: delayed degenerate path checking.
 	 */