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authorLinus Torvalds <torvalds@linux-foundation.org>2018-11-16 09:30:13 -0600
committerLinus Torvalds <torvalds@linux-foundation.org>2018-11-16 09:30:13 -0600
commit9b5f361ac4a923bf53ca8c0875509ef68c8958cd (patch)
tree07edca4e552da466dab697ff1c8932ffa8679730
parentda5322e65940e4e8426613a8ff3d99a08b350a52 (diff)
parentebacb81273599555a7a19f7754a1451206a5fc4f (diff)
downloadlinux-9b5f361ac4a923bf53ca8c0875509ef68c8958cd.tar.bz2
Merge tag 'fuse-fixes-4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse fixes from Miklos Szeredi: "A couple of fixes, all bound for -stable (i.e. not regressions in this cycle)" * tag 'fuse-fixes-4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: fix use-after-free in fuse_direct_IO() fuse: fix possibly missed wake-up after abort fuse: fix leaked notify reply
-rw-r--r--fs/fuse/dev.c16
-rw-r--r--fs/fuse/file.c4
2 files changed, 15 insertions, 5 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ae813e609932..a5e516a40e7a 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -165,9 +165,13 @@ static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
static void fuse_drop_waiting(struct fuse_conn *fc)
{
- if (fc->connected) {
- atomic_dec(&fc->num_waiting);
- } else if (atomic_dec_and_test(&fc->num_waiting)) {
+ /*
+ * lockess check of fc->connected is okay, because atomic_dec_and_test()
+ * provides a memory barrier mached with the one in fuse_wait_aborted()
+ * to ensure no wake-up is missed.
+ */
+ if (atomic_dec_and_test(&fc->num_waiting) &&
+ !READ_ONCE(fc->connected)) {
/* wake up aborters */
wake_up_all(&fc->blocked_waitq);
}
@@ -1768,8 +1772,10 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
req->in.args[1].size = total_len;
err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
- if (err)
+ if (err) {
fuse_retrieve_end(fc, req);
+ fuse_put_request(fc, req);
+ }
return err;
}
@@ -2219,6 +2225,8 @@ EXPORT_SYMBOL_GPL(fuse_abort_conn);
void fuse_wait_aborted(struct fuse_conn *fc)
{
+ /* matches implicit memory barrier in fuse_drop_waiting() */
+ smp_mb();
wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
}
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index cc2121b37bf5..b52f9baaa3e7 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2924,10 +2924,12 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
}
if (io->async) {
+ bool blocking = io->blocking;
+
fuse_aio_complete(io, ret < 0 ? ret : 0, -1);
/* we have a non-extending, async request, so return */
- if (!io->blocking)
+ if (!blocking)
return -EIOCBQUEUED;
wait_for_completion(&wait);