6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicolin Chen <nicolinc@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object")
Link: https://patch.msgid.link/r/b5651beb3a6b1adeef26fffac24607353bf67ba1.1733212723.git.nicolinc@xxxxxxxxxx
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
Reviewed-by: Yi Liu <yi.l.liu@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
