6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicolin Chen nicolinc@nvidia.com
commit af7f4780514f850322b2959032ecaa96e4b26472 upstream.
As fput() calls the file->f_op->release op, where fault obj and ictx are getting released, there is no need to release these two after fput() one more time, which would result in imbalanced refcounts: refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 48 PID: 2369 at lib/refcount.c:31 refcount_warn_saturate+0x60/0x230 Call trace: refcount_warn_saturate+0x60/0x230 (P) refcount_warn_saturate+0x60/0x230 (L) iommufd_fault_fops_release+0x9c/0xe0 [iommufd] ... VFS: Close: file count is 0 (f_op=iommufd_fops [iommufd]) WARNING: CPU: 48 PID: 2369 at fs/open.c:1507 filp_flush+0x3c/0xf0 Call trace: filp_flush+0x3c/0xf0 (P) filp_flush+0x3c/0xf0 (L) __arm64_sys_close+0x34/0x98 ... imbalanced put on file reference count WARNING: CPU: 48 PID: 2369 at fs/file.c:74 __file_ref_put+0x100/0x138 Call trace: __file_ref_put+0x100/0x138 (P) __file_ref_put+0x100/0x138 (L) __fput_sync+0x4c/0xd0
Drop those two lines to fix the warnings above.
Cc: stable@vger.kernel.org Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object") Link: https://patch.msgid.link/r/b5651beb3a6b1adeef26fffac24607353bf67ba1.17332127... Signed-off-by: Nicolin Chen nicolinc@nvidia.com Reviewed-by: Yi Liu yi.l.liu@intel.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/iommufd/fault.c | 2 -- 1 file changed, 2 deletions(-)
--- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -415,8 +415,6 @@ out_put_fdno: put_unused_fd(fdno); out_fput: fput(filep); - refcount_dec(&fault->obj.users); - iommufd_ctx_put(fault->ictx); out_abort: iommufd_object_abort_and_destroy(ucmd->ictx, &fault->obj);