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| author | Alexander Aring <aahringo@redhat.com> | 2024-03-12 20:05:07 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-03 16:28:32 +0300 |
| commit | 700ed41bf63ec22af3611fc32f7af4285f6aff6f (patch) | |
| tree | 260e8b70e91670f133d6beae87a1ccfd7b2a71ff | |
| parent | b31301a1fa61d7a854b3a1914e8119adb799db3d (diff) | |
| download | linux-700ed41bf63ec22af3611fc32f7af4285f6aff6f.tar.xz | |
dlm: fix user space lkb refcounting
[ Upstream commit 2ab3d705ca5d4f7ea345a21c3da41a447a549649 ]
This patch fixes to check on the right return value if it was the last
callback. The rv variable got overwritten by the return of
copy_result_to_user(). Fixing it by introducing a second variable for
the return value and don't let rv being overwritten.
Cc: stable@vger.kernel.org
Fixes: 61bed0baa4db ("fs: dlm: use a non-static queue for callbacks")
Reported-by: Valentin Vidić <vvidic@valentin-vidic.from.hr>
Closes: https://lore.kernel.org/gfs2/Ze4qSvzGJDt5yxC3@valentin-vidic.from.hr
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/dlm/user.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 695e691b38b3..9f9b68448830 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -806,7 +806,7 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, struct dlm_lkb *lkb; DECLARE_WAITQUEUE(wait, current); struct dlm_callback *cb; - int rv, copy_lvb = 0; + int rv, ret, copy_lvb = 0; int old_mode, new_mode; if (count == sizeof(struct dlm_device_version)) { @@ -906,9 +906,9 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, trace_dlm_ast(lkb->lkb_resource->res_ls, lkb); } - rv = copy_result_to_user(lkb->lkb_ua, - test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), - cb->flags, cb->mode, copy_lvb, buf, count); + ret = copy_result_to_user(lkb->lkb_ua, + test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), + cb->flags, cb->mode, copy_lvb, buf, count); kref_put(&cb->ref, dlm_release_callback); @@ -916,7 +916,7 @@ static ssize_t device_read(struct file *file, char __user *buf, size_t count, if (rv == DLM_DEQUEUE_CALLBACK_LAST) dlm_put_lkb(lkb); - return rv; + return ret; } static __poll_t device_poll(struct file *file, poll_table *wait) |