This is a note to let you know that I've just added the patch titled
misc: mic: scif: Fix error handling path
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
misc-mic-scif-fix-error-handling-path.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0b2db552f35c6af2f6ddec1bf45aef95555c2221
Author: Souptick Joarder <jrdr.linux@xxxxxxxxx>
Date: Sun Sep 20 08:21:35 2020 +0530
misc: mic: scif: Fix error handling path
[ 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@xxxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
Link: https://lore.kernel.org/r/1600570295-29546-1-git-send-email-jrdr.linux@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/misc/mic/scif/scif_rma.c b/drivers/misc/mic/scif/scif_rma.c
index 2da3b474f4863..18fb9d8b8a4b5 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,
