When calling fcntl(F_SETLEASE) for a second time on the same fd, do_fcntl_add_lease
will allocate and initialize a new file_lock, then if __vfs_setlease decides to
reuse the existing file_lock it will free the newly allocated one to prevent leaking
memory.
However, the new file_lock was initialized to the point where it has a valid file
descriptor pointer and lmops, so calling locks_free_lock will trigger a call to
lease_release_private_callback which will have the side effect of clearing the
fcntl(F_SETOWN) and fcntl(F_SETSIG) settings for the file descriptor even though
that was not supposed to happen at that point.
This patch will fix this by calling kmem_cache_free(filelock_cache, fl) instead of
locks_free_lock(fl) if the file_lock is not completely initialized and actually
associated to the file descriptor, avoiding the call to lease_release_private_callback
with the undesired side effects.
Signed-off-by: Filipe Brandenburger <filbranden@xxxxxxxxx>
---
fs/locks.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index 814c51d..ce57c59 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -473,7 +473,7 @@ static struct file_lock *lease_alloc(struct file *filp, int type)
error = lease_init(filp, type, fl);
if (error) {
- locks_free_lock(fl);
+ kmem_cache_free(filelock_cache, fl);
return ERR_PTR(error);
}
return fl;
@@ -1538,7 +1538,7 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
new = fasync_alloc();
if (!new) {
- locks_free_lock(fl);
+ kmem_cache_free(filelock_cache, fl);
return -ENOMEM;
}
ret = fl;
@@ -1546,11 +1546,11 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
error = __vfs_setlease(filp, arg, &ret);
if (error) {
unlock_flocks();
- locks_free_lock(fl);
+ kmem_cache_free(filelock_cache, fl);
goto out_free_fasync;
}
if (ret != fl)
- locks_free_lock(fl);
+ kmem_cache_free(filelock_cache, fl);
/*
* fasync_insert_entry() returns the old entry if any.
--
1.7.7.6
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