fix a leak in replace_fd() users

replace_fd() began with "eats a reference, tries to insert into
descriptor table" semantics; at some point I'd switched it to
much saner current behaviour ("try to insert into descriptor
table, grabbing a new reference if inserted; caller should do
fput() in any case"), but forgot to update the callers.
Mea culpa...

[Spotted by Pavel Roskin, who has really weird system with pipe-fed
coredumps as part of what he considers a normal boot ;-)]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/coredump.c b/fs/coredump.c
index fd37fac..ce47379 100644 (file)
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -450,11 +450,12 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
 
        cp->file = files[1];
 
-       replace_fd(0, files[0], 0);
+       err = replace_fd(0, files[0], 0);
+       fput(files[0]);
        /* and disallow core files too */
        current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
 
-       return 0;
+       return err;
 }
 
 void do_coredump(siginfo_t *siginfo, struct pt_regs *regs)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 24ab414..61a5336 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2132,18 +2132,14 @@ static inline void flush_unauthorized_files(const struct cred *cred,
                return;
 
        devnull = dentry_open(&selinux_null, O_RDWR, cred);
-       if (!IS_ERR(devnull)) {
-               /* replace all the matching ones with this */
-               do {
-                       replace_fd(n - 1, get_file(devnull), 0);
-               } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
+       if (IS_ERR(devnull))
+               devnull = NULL;
+       /* replace all the matching ones with this */
+       do {
+               replace_fd(n - 1, devnull, 0);
+       } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
+       if (devnull)
                fput(devnull);
-       } else {
-               /* just close all the matching ones */
-               do {
-                       replace_fd(n - 1, NULL, 0);
-               } while ((n = iterate_fd(files, n, match_file, cred)) != 0);
-       }
 }
 
 /*