From: Nicolin Chen <nicolinc@nvidia.com> mainline inclusion from mainline-v6.13-rc2 commit af7f4780514f850322b2959032ecaa96e4b26472 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAOW CVE: CVE-2024-56624 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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: GONG Ruiqi <gongruiqi1@huawei.com> --- drivers/iommu/iommufd/fault.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/iommu/iommufd/fault.c b/drivers/iommu/iommufd/fault.c index 11c70922ec47..f8c8bbf8e457 100644 --- a/drivers/iommu/iommufd/fault.c +++ b/drivers/iommu/iommufd/fault.c @@ -431,8 +431,6 @@ int iommufd_fault_alloc(struct iommufd_ucmd *ucmd) 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); -- 2.25.1