On 9/19/20 7:51 PM, Souptick Joarder wrote:
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 <[email protected]> Cc: John Hubbard <[email protected]> Cc: Ira Weiny <[email protected]> Cc: Dan Carpenter <[email protected]> ---
Reviewed-by: John Hubbard <[email protected]> thanks, -- John Hubbard NVIDIA
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,
