From: Souptick Joarder jrdr.linux@gmail.com
[ Upstream commit a81072a9c0ae734b7889929b0bc070fe3f353f0e ]
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") Cc: John Hubbard jhubbard@nvidia.com Cc: Ira Weiny ira.weiny@intel.com Cc: Dan Carpenter dan.carpenter@oracle.com Reviewed-by: John Hubbard jhubbard@nvidia.com Signed-off-by: Souptick Joarder jrdr.linux@gmail.com Link: https://lore.kernel.org/r/1600570295-29546-1-git-send-email-jrdr.linux@gmail... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 32ab0f43f5061..4e2cfb6eea353 100644 --- a/drivers/misc/mic/scif/scif_rma.c +++ b/drivers/misc/mic/scif/scif_rma.c @@ -1401,6 +1401,8 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot, NULL); up_write(&mm->mmap_sem); 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, @@ -1421,7 +1423,6 @@ 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; }
@@ -1434,7 +1435,6 @@ int __scif_pin_pages(void *addr, size_t len, int *out_prot, __scif_dec_pinned_vm_lock(mm, nr_pages, 0); /* 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,