Messages in this thread Patch in this message | | | From | Souptick Joarder <> | Subject | [PATCH] misc: mic: scif: Fix error handling path | Date | Sun, 20 Sep 2020 08:21:35 +0530 |
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Inside __scif_pin_pages(), when map_flags != SCIF_MAP_KERNEL it will call pin_user_pages_fast() to map nr_pages. However, pin_user_pages_fast() might fail with a return value -ERRNO.
The return value is stored in pinned_pages->nr_pages. which in turn is passed to unpin_user_pages(), which expects pinned_pages->nr_pages >=0, else disaster.
Fix this by assigning pinned_pages->nr_pages to 0 if pin_user_pages_fast() returns -ERRNO.
Fixes: ba612aa8b487 ("misc: mic: SCIF memory registration and unregistration") Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/misc/mic/scif/scif_rma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c index 2da3b47..18fb9d8 100644 --- a/drivers/misc/mic/scif/scif_rma.c +++ b/drivers/misc/mic/scif/scif_rma.c @@ -1392,6 +1392,8 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot, (prot & SCIF_PROT_WRITE) ? FOLL_WRITE : 0, pinned_pages->pages); if (nr_pages != pinned_pages->nr_pages) { + if (pinned_pages->nr_pages < 0) + pinned_pages->nr_pages = 0; if (try_upgrade) { if (ulimit) __scif_dec_pinned_vm_lock(mm, nr_pages); @@ -1408,7 +1410,6 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot, if (pinned_pages->nr_pages < nr_pages) { err = -EFAULT; - pinned_pages->nr_pages = nr_pages; goto dec_pinned; } @@ -1421,7 +1422,6 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot, __scif_dec_pinned_vm_lock(mm, nr_pages); /* Something went wrong! Rollback */ error_unmap: - pinned_pages->nr_pages = nr_pages; scif_destroy_pinned_pages(pinned_pages); *pages = NULL; dev_dbg(scif_info.mdev.this_device, -- 1.9.1
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